1.
NASA
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President Dwight D. Eisenhower established NASA in 1958 with a distinctly civilian orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29,1958, disestablishing NASAs predecessor, the new agency became operational on October 1,1958. Since that time, most US space exploration efforts have led by NASA, including the Apollo Moon landing missions, the Skylab space station. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the agency is also responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA shares data with various national and international such as from the Greenhouse Gases Observing Satellite. Since 2011, NASA has been criticized for low cost efficiency, from 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1. In the early 1950s, there was challenge to launch a satellite for the International Geophysical Year. An effort for this was the American Project Vanguard, after the Soviet launch of the worlds first artificial satellite on October 4,1957, the attention of the United States turned toward its own fledgling space efforts. This led to an agreement that a new federal agency based on NACA was needed to conduct all non-military activity in space. The Advanced Research Projects Agency was created in February 1958 to develop technology for military application. On July 29,1958, Eisenhower signed the National Aeronautics and Space Act, a NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA, earlier research efforts within the US Air Force and many of ARPAs early space programs were also transferred to NASA. In December 1958, NASA gained control of the Jet Propulsion Laboratory, NASA has conducted many manned and unmanned spaceflight programs throughout its history. Some missions include both manned and unmanned aspects, such as the Galileo probe, which was deployed by astronauts in Earth orbit before being sent unmanned to Jupiter, the experimental rocket-powered aircraft programs started by NACA were extended by NASA as support for manned spaceflight. This was followed by a space capsule program, and in turn by a two-man capsule program. This goal was met in 1969 by the Apollo program, however, reduction of the perceived threat and changing political priorities almost immediately caused the termination of most of these plans. NASA turned its attention to an Apollo-derived temporary space laboratory, to date, NASA has launched a total of 166 manned space missions on rockets, and thirteen X-15 rocket flights above the USAF definition of spaceflight altitude,260,000 feet. The X-15 was an NACA experimental rocket-powered hypersonic research aircraft, developed in conjunction with the US Air Force, the design featured a slender fuselage with fairings along the side containing fuel and early computerized control systems
2.
Atlas II
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Atlas II was a member of the Atlas family of launch vehicles, which evolved from the successful Atlas missile program of the 1950s. It was designed to launch payloads into low orbit, geosynchronous transfer orbit or geosynchronous orbit. The Atlas line was continued by the Atlas III, used between 2000 and 2005, and the Atlas V which is still in use, Atlas II provided higher performance than the earlier Atlas I by using engines with greater thrust and longer fuel tanks for both stages. LR-89 and RS-27 were replaced by the RS-56, derived from the RS-27, the total thrust capability of the Atlas II of 490,000 pounds force enabled the booster to lift payloads of 6,100 pounds into geosynchronous transfer orbit of 22,000 miles or more. Atlas II was the last Atlas to use a three engine, stage-and-a-half design, two of its three engines were jettisoned during ascent, but its fuel tanks and other elements were retained. The two booster engines, RS-56-OBAs, were integrated into a unit called the MA-5A and shared a common gas generator. They burned for 164 seconds before being jettisoned, the central sustainer engine, an RS-56-OSA, would burn for an additional 125 seconds. The Vernier engines on the first stage of the Atlas I were replaced by a hydrazine fueled roll control system and this series used an improved Centaur upper stage, the world’s first cryogenic propellant stage, to increase its payload capability. Atlas II also had lower-cost electronics, a flight computer and longer propellant tanks than its predecessor. The original Atlas II was based on the Atlas I and its predecessors and this version flew between 1991 and 1998. Atlas IIA was a designed to service the commercial launch market. The main improvement was the switch from the RL10A-3-3A to RL10A-4 engine on the Centaur upper stage, the IIA version flew between 1992 and 2002. Atlas IIAS was largely identical to IIA, but added four Castor 4A solid rocket boosters to increase performance and these boosters were ignited in pairs, with one pair igniting on the ground, and the second igniting in the air shortly after the first pair separated. The half-stage booster section would then drop off as usual, IIAS was used between 1993 and 2004, concurrently with IIA. Led by lead engineer Samuel Wagner, the Atlas II was crucial to the development of the United States space program. Atlas IIs were launched from Cape Canaveral Air Force Station, Fla. by the 45th Space Wing, the final West Coast Atlas II launch was accomplished December 2003 by the 30th Space Wing, Vandenberg AFB, California
3.
Vandenberg Air Force Base
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Vandenberg Air Force Base is a United States Air Force Base 9.2 miles northwest of Lompoc, California. It is under the jurisdiction of the 30th Space Wing, Air Force Space Command, Vandenberg AFB is a Department of Defense space and missile testing base, with a mission of placing satellites into polar orbit from the West Coast using expendable boosters. Wing personnel also support the Services LGM-30G Minuteman III Intercontinental Ballistic Missile Force Development Evaluation program, in addition to its military mission, the base also leases launch pad facilities to SpaceX, as well as 100 acres leased to the California Spaceport in 1995. Established in 1941, the base is named in honor of former Air Force Chief of Staff General Hoyt Vandenberg, the host unit at Vandenberg AFB is the 30th Space Wing. The 30th SW is home to the Western Range, manages Department of Defense space and missile testing, Wing personnel also support the Air Forces Minuteman III Intercontinental Ballistic Missile Force Development Test and Evaluation program. The Western Range begins at the boundaries of Vandenberg and extends westward from the California coast to the Western Pacific. Operations involve dozens of federal and commercial interests, the wing is organized into operations, launch, mission support and medical groups, along with several directly assigned staff agencies. 30th Launch Group The 30th Launch Group is responsible for booster and satellite technical oversight and launch processing activities to launch, integration. The group consists of a military, civilian and contractor team with more than 250 personnel directly supporting operations from the Western Range. 1st Air and Space Test Squadron 4th Space Launch Squadron 30th Operations Group The 30th Operations Group provides the capability for West Coast spacelift. Operations professionals are responsible for operating and maintaining the Western Range for spacelift, missile test launch, aeronautical, 30th Mission Support Group The 30th Mission Support Group supports the third largest Air Force Base in the United States. It is also responsible for quality-of-life needs, housing, personnel, services, civil engineering, contracting, 30th Medical Group The 30th Medical Group provides medical, dental, bio-environmental and public health services for people assigned to Vandenberg Air Force Base, their families and retirees. It is Vandenbergs only National Historic Landmark that is open for scheduled tours through the 30th Space Wings Public Affairs office. The current display area is made up of two exhibits, the Chronology of the Cold War and the Evolution of Technology, there are plans to evolve the center in stages from the current exhibit areas as restorations of additional facilities are completed. In 1941 the United States Army sought more and better training centers for the development of its armored. In March 1941, the Army acquired approximately 86,000 acres of open ranch lands along the Central Coast of California between Lompoc and Santa Maria, most of the land was purchased. Smaller parcels were obtained either by lease, license, or as easements, with its flat plateau, surrounding hills, numerous canyons, and relative remoteness from populated areas, the Army was convinced it had found the ideal training location. Construction of the Army camp began in September 1941, although its completion was still months away, the Army activated the camp on 5 October, and named it Camp Cooke in honor of Major General Phillip St. George Cooke
4.
Vandenberg AFB Space Launch Complex 3
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Space Launch Complex 3 is a launch site at Vandenberg Air Force Base that has been used by Atlas and Thor rockets. It was built in the early 1960s and consists of two pads, SLC-3E and SLC-3W, the East-West coastline at Vandenberg allows SLC-3 to launch over-ocean polar trajectories that avoid landfall until passing over Antarctica. By contrast, Cape Canaveral has a North-South coastline permitting over-ocean launches into standard orbits, three successful Atlas IIAS missions were flown from SLC-3E. The first mission, flown on December 18,1999, launched the Terra satellite, the other two launched satellites in the Naval Ocean Surveillance System, USA160 and USA173. The final Atlas IIAS mission from SLC-3E was launched on December 2,2003, the tower can thus accommodate an Atlas V500 series vehicle with its larger payload fairing. In July 2004 Lockheed Martin announced the arrival of the fourth, the segments had been transported from a fabrication facility in Oak Hill, FL,3,500 miles away. The largest segment weighed 90 tons and, is thought to be the biggest over-the-road shipment ever attempted cross-country, in February 2005 the activations team handed over the launch pad to the operational team, marking the end of major reconstruction. The first Atlas V launch from SLC-3E took place at 10,02 GMT on March 13,2008, SLC-3W was originally built for Atlas-Agena launches and the first flight off the pad was the launch of Samos 1 in October 1960. The facility was extensively damaged 11 months later when Samos 3s booster exploded on the pad, in 1962-63, the pad was converted for Thor-Agena use and was the primary launching site for Corona reconnaissance satellites for the next decade. After the Corona program ended in 1972, SLC-3W was converted back to support Atlases, the final such launch took place in 1995. SpaceX initially planned to use SLC-3W for the Falcon 1 launch vehicle, canyon Fire - A2016 wildfire that burned near the Launch Complex
5.
International Launch Services
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International Launch Services is an American-Russian joint venture with exclusive rights to the worldwide sale of commercial Proton rocket launch services from the Baikonur Cosmodrome in Kazakhstan. ILS was formed in 1995 as a private partnership between Lockheed Martin, Khrunichev and Energia. ILS initially co-marketed non-military launches on both the U. S. Atlas and the Russian Proton expendable launch vehicles, with the Atlas V launch of the SES 1KR satellite on April 20,2006, ILS had made 100 launches,97 of which were successful. Space Transport Inc. was formed specifically for this transaction by Mario Lemme, who has been a consultant to ILS since its inception, the transaction between Lockheed Martin and Space Transport Inc. completed in October 2006. ILS, no longer affiliated with Lockheed Martin, continued to market the Proton launch vehicles to commercial clients, terms of the transaction were not disclosed. In October 2006, Krunichev spokesman said that the firm was ready to buy the stake being sold by Lockheed Martin, Russian space agency spokesman said that despite that Lockheed is selling its stake to Space Transport, Khrunichev may eventually end up owning it. He expressed the desire of the Russian side to increase its presence in the joint venture, Space Transport Inc, registered in the British Virgin Islands and headquartered in Moscow, denied that it would be selling the stake. In May 2008, Khrunichev State Research and Production Space Center, ILS will remain a U. S. company and headquarters are currently in Reston, Virginia, near Washington, D. C. where approximately 60 employees are based. In May 2008, ILS had a backlog of 22 orders, totaling approximately $2 billion, by June 2009, the backlog had grown to 24 firm missions. The 50th ILS Proton launch took place in early 2009, in January 2014 ILS had an order book of 14 launches worth more than $1 billion, with up to 6 launches planned for 2014. After October 2006, ILS focused solely on the Proton launch vehicle, the first Atlas launch was the Atlas IIAS Intelsat 704 launch on 10 January 1995 and the last was the Atlas V Astra 1KR launch on 20 April 2006. NewSpace ILS Website Proton rockets commercial marketer begins new era, Spaceflight Now, November 8,2006
6.
Geocentric orbit
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A geocentric orbit or Earth orbit involves any object orbiting the Earth, such as the Moon or artificial satellites. In 1997 NASA estimated there were approximately 2,465 artificial satellite orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. Over 16,291 previously launched objects have decayed into the Earths atmosphere, altitude as used here, the height of an object above the average surface of the Earths oceans. Analemma a term in astronomy used to describe the plot of the positions of the Sun on the celestial sphere throughout one year, apogee is the farthest point that a satellite or celestial body can go from Earth, at which the orbital velocity will be at its minimum. Eccentricity a measure of how much an orbit deviates from a perfect circle, eccentricity is strictly defined for all circular and elliptical orbits, and parabolic and hyperbolic trajectories. Equatorial plane as used here, an imaginary plane extending from the equator on the Earth to the celestial sphere, escape velocity as used here, the minimum velocity an object without propulsion needs to have to move away indefinitely from the Earth. An object at this velocity will enter a parabolic trajectory, above this velocity it will enter a hyperbolic trajectory, impulse the integral of a force over the time during which it acts. Inclination the angle between a plane and another plane or axis. In the sense discussed here the reference plane is the Earths equatorial plane, orbital characteristics the six parameters of the Keplerian elements needed to specify that orbit uniquely. Orbital period as defined here, time it takes a satellite to make one orbit around the Earth. Perigee is the nearest approach point of a satellite or celestial body from Earth, sidereal day the time it takes for a celestial object to rotate 360°. For the Earth this is,23 hours,56 minutes,4.091 seconds, solar time as used here, the local time as measured by a sundial. Velocity an objects speed in a particular direction, since velocity is defined as a vector, both speed and direction are required to define it. The following is a list of different geocentric orbit classifications, Low Earth orbit - Geocentric orbits ranging in altitude from 160 kilometers to 2,000 kilometres above mean sea level. At 160 km, one revolution takes approximately 90 minutes, medium Earth orbit - Geocentric orbits with altitudes at apogee ranging between 2,000 kilometres and that of the geosynchronous orbit at 35,786 kilometres. Geosynchronous orbit - Geocentric circular orbit with an altitude of 35,786 kilometres, the period of the orbit equals one sidereal day, coinciding with the rotation period of the Earth. The speed is approximately 3,000 metres per second, high Earth orbit - Geocentric orbits with altitudes at apogee higher than that of the geosynchronous orbit. A special case of high Earth orbit is the elliptical orbit
7.
Low Earth orbit
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A low Earth orbit is an orbit around Earth with an altitude between 160 kilometers, and 2,000 kilometers. Objects below approximately 160 kilometers will experience very rapid orbital decay, with the exception of the 24 human beings who flew lunar flights in the Apollo program during the four-year period spanning 1968 through 1972, all human spaceflights have taken place in LEO or below. The International Space Station conducts operations in LEO, the altitude record for a human spaceflight in LEO was Gemini 11 with an apogee of 1,374.1 kilometers. All crewed space stations to date, as well as the majority of satellites, have been in LEO, objects in LEO encounter atmospheric drag from gases in the thermosphere or exosphere, depending on orbit height. Due to atmospheric drag, satellites do not usually orbit below 300 km, objects in LEO orbit Earth between the denser part of the atmosphere and below the inner Van Allen radiation belt. The mean orbital velocity needed to maintain a stable low Earth orbit is about 7.8 km/s, calculated for circular orbit of 200 km it is 7.79 km/s and for 1500 km it is 7.12 km/s. The delta-v needed to achieve low Earth orbit starts around 9.4 km/s, atmospheric and gravity drag associated with launch typically adds 1. 3–1.8 km/s to the launch vehicle delta-v required to reach normal LEO orbital velocity of around 7.8 km/s. Equatorial low Earth orbits are a subset of LEO and these orbits, with low inclination to the Equator, allow rapid revisit times and have the lowest delta-v requirement of any orbit. Orbits with an inclination angle to the equator are usually called polar orbits. Higher orbits include medium Earth orbit, sometimes called intermediate circular orbit, orbits higher than low orbit can lead to early failure of electronic components due to intense radiation and charge accumulation. Although the Earths pull due to gravity in LEO is not much less than on the surface of the Earth, people, a low Earth orbit is simplest and cheapest for satellite placement. It provides high bandwidth and low communication time lag, but satellites in LEO will not be visible from any point on the Earth at all times. Earth observation satellites and spy satellites use LEO as they are able to see the surface of the Earth more clearly as they are not so far away and they are also able to traverse the surface of the Earth. A majority of satellites are placed in LEO, making one complete revolution around the Earth in about 90 minutes. The International Space Station is in a LEO about 400 km above the Earths surface, since it requires less energy to place a satellite into a LEO and the LEO satellite needs less powerful amplifiers for successful transmission, LEO is used for many communication applications. Because these LEO orbits are not geostationary, a network of satellites is required to provide continuous coverage, lower orbits also aid remote sensing satellites because of the added detail that can be gained. Remote sensing satellites can also take advantage of sun-synchronous LEO orbits at an altitude of about 800 km, envisat is one example of an Earth observation satellite that makes use of this particular type of LEO. The LEO environment is becoming congested with space debris due to the frequency of object launches and this has caused growing concern in recent years, since collisions at orbital velocities can easily be dangerous, and even deadly
8.
Semi-major and semi-minor axes
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In geometry, the major axis of an ellipse is its longest diameter, a line segment that runs through the center and both foci, with ends at the widest points of the perimeter. The semi-major axis is one half of the axis, and thus runs from the centre, through a focus. Essentially, it is the radius of an orbit at the two most distant points. For the special case of a circle, the axis is the radius. One can think of the axis as an ellipses long radius. The semi-major axis of a hyperbola is, depending on the convention, thus it is the distance from the center to either vertex of the hyperbola. A parabola can be obtained as the limit of a sequence of ellipses where one focus is fixed as the other is allowed to move arbitrarily far away in one direction. Thus a and b tend to infinity, a faster than b, the semi-minor axis is a line segment associated with most conic sections that is at right angles with the semi-major axis and has one end at the center of the conic section. It is one of the axes of symmetry for the curve, in an ellipse, the one, in a hyperbola. The semi-major axis is the value of the maximum and minimum distances r max and r min of the ellipse from a focus — that is. In astronomy these extreme points are called apsis, the semi-minor axis of an ellipse is the geometric mean of these distances, b = r max r min. The eccentricity of an ellipse is defined as e =1 − b 2 a 2 so r min = a, r max = a. Now consider the equation in polar coordinates, with one focus at the origin, the mean value of r = ℓ / and r = ℓ /, for θ = π and θ =0 is a = ℓ1 − e 2. In an ellipse, the axis is the geometric mean of the distance from the center to either focus. The semi-minor axis of an ellipse runs from the center of the ellipse to the edge of the ellipse, the semi-minor axis is half of the minor axis. The minor axis is the longest line segment perpendicular to the axis that connects two points on the ellipses edge. The semi-minor axis b is related to the axis a through the eccentricity e. A parabola can be obtained as the limit of a sequence of ellipses where one focus is fixed as the other is allowed to move arbitrarily far away in one direction
9.
Orbital eccentricity
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The orbital eccentricity of an astronomical object is a parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is an orbit, values between 0 and 1 form an elliptical orbit,1 is a parabolic escape orbit. The term derives its name from the parameters of conic sections and it is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the galaxy. In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit, the eccentricity of this Kepler orbit is a non-negative number that defines its shape. The limit case between an ellipse and a hyperbola, when e equals 1, is parabola, radial trajectories are classified as elliptic, parabolic, or hyperbolic based on the energy of the orbit, not the eccentricity. Radial orbits have zero angular momentum and hence eccentricity equal to one, keeping the energy constant and reducing the angular momentum, elliptic, parabolic, and hyperbolic orbits each tend to the corresponding type of radial trajectory while e tends to 1. For a repulsive force only the trajectory, including the radial version, is applicable. For elliptical orbits, a simple proof shows that arcsin yields the projection angle of a circle to an ellipse of eccentricity e. For example, to view the eccentricity of the planet Mercury, next, tilt any circular object by that angle and the apparent ellipse projected to your eye will be of that same eccentricity. From Medieval Latin eccentricus, derived from Greek ἔκκεντρος ekkentros out of the center, from ἐκ- ek-, eccentric first appeared in English in 1551, with the definition a circle in which the earth, sun. Five years later, in 1556, a form of the word was added. The eccentricity of an orbit can be calculated from the state vectors as the magnitude of the eccentricity vector, e = | e | where. For elliptical orbits it can also be calculated from the periapsis and apoapsis since rp = a and ra = a, where a is the semimajor axis. E = r a − r p r a + r p =1 −2 r a r p +1 where, rp is the radius at periapsis. For Earths annual orbit path, ra/rp ratio = longest_radius / shortest_radius ≈1.034 relative to center point of path, the eccentricity of the Earths orbit is currently about 0.0167, the Earths orbit is nearly circular. Venus and Neptune have even lower eccentricity, over hundreds of thousands of years, the eccentricity of the Earths orbit varies from nearly 0.0034 to almost 0.058 as a result of gravitational attractions among the planets. The table lists the values for all planets and dwarf planets, Mercury has the greatest orbital eccentricity of any planet in the Solar System. Such eccentricity is sufficient for Mercury to receive twice as much solar irradiation at perihelion compared to aphelion, before its demotion from planet status in 2006, Pluto was considered to be the planet with the most eccentric orbit
10.
Apsis
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An apsis is an extreme point in an objects orbit. The word comes via Latin from Greek and is cognate with apse, for elliptic orbits about a larger body, there are two apsides, named with the prefixes peri- and ap-, or apo- added to a reference to the thing being orbited. For a body orbiting the Sun, the point of least distance is the perihelion, the terms become periastron and apastron when discussing orbits around other stars. For any satellite of Earth including the Moon the point of least distance is the perigee, for objects in Lunar orbit, the point of least distance is the pericynthion and the greatest distance the apocynthion. For any orbits around a center of mass, there are the terms pericenter and apocenter, periapsis and apoapsis are equivalent alternatives. A straight line connecting the pericenter and apocenter is the line of apsides and this is the major axis of the ellipse, its greatest diameter. For a two-body system the center of mass of the lies on this line at one of the two foci of the ellipse. When one body is larger than the other it may be taken to be at this focus. Historically, in systems, apsides were measured from the center of the Earth. In orbital mechanics, the apsis technically refers to the distance measured between the centers of mass of the central and orbiting body. However, in the case of spacecraft, the family of terms are used to refer to the orbital altitude of the spacecraft from the surface of the central body. The arithmetic mean of the two limiting distances is the length of the axis a. The geometric mean of the two distances is the length of the semi-minor axis b, the geometric mean of the two limiting speeds is −2 ε = μ a which is the speed of a body in a circular orbit whose radius is a. The words pericenter and apocenter are often seen, although periapsis/apoapsis are preferred in technical usage, various related terms are used for other celestial objects. The -gee, -helion and -astron and -galacticon forms are used in the astronomical literature when referring to the Earth, Sun, stars. The suffix -jove is occasionally used for Jupiter, while -saturnium has very rarely used in the last 50 years for Saturn. The -gee form is used as a generic closest approach to planet term instead of specifically applying to the Earth. During the Apollo program, the terms pericynthion and apocynthion were used when referring to the Moon, regarding black holes, the term peri/apomelasma was used by physicist Geoffrey A. Landis in 1998 before peri/aponigricon appeared in the scientific literature in 2002
11.
Orbital inclination
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Orbital inclination measures the tilt of an objects orbit around a celestial body. It is expressed as the angle between a plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the equator, the plane of the orbit is the same as the Earths equatorial plane. The general case is that the orbit is tilted, it spends half an orbit over the northern hemisphere. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°, the inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planets equator, for planets in the Solar System, the plane of reference is usually the ecliptic, the plane in which the Earth orbits the Sun. This reference plane is most practical for Earth-based observers, therefore, Earths inclination is, by definition, zero. Inclination could instead be measured with respect to another plane, such as the Suns equator or the invariable plane, the inclination of orbits of natural or artificial satellites is measured relative to the equatorial plane of the body they orbit, if they orbit sufficiently closely. The equatorial plane is the perpendicular to the axis of rotation of the central body. An inclination of 30° could also be described using an angle of 150°, the convention is that the normal orbit is prograde, an orbit in the same direction as the planet rotates. Inclinations greater than 90° describe retrograde orbits, thus, An inclination of 0° means the orbiting body has a prograde orbit in the planets equatorial plane. An inclination greater than 0° and less than 90° also describe prograde orbits, an inclination of 63. 4° is often called a critical inclination, when describing artificial satellites orbiting the Earth, because they have zero apogee drift. An inclination of exactly 90° is an orbit, in which the spacecraft passes over the north and south poles of the planet. An inclination greater than 90° and less than 180° is a retrograde orbit, an inclination of exactly 180° is a retrograde equatorial orbit. For gas giants, the orbits of moons tend to be aligned with the giant planets equator, the inclination of exoplanets or members of multiple stars is the angle of the plane of the orbit relative to the plane perpendicular to the line-of-sight from Earth to the object. An inclination of 0° is an orbit, meaning the plane of its orbit is parallel to the sky. An inclination of 90° is an orbit, meaning the plane of its orbit is perpendicular to the sky
12.
Longitude of the ascending node
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The longitude of the ascending node is one of the orbital elements used to specify the orbit of an object in space. It is the angle from a direction, called the origin of longitude, to the direction of the ascending node. The ascending node is the point where the orbit of the passes through the plane of reference. Commonly used reference planes and origins of longitude include, For a geocentric orbit, Earths equatorial plane as the plane. In this case, the longitude is called the right ascension of the ascending node. The angle is measured eastwards from the First Point of Aries to the node, for a heliocentric orbit, the ecliptic as the reference plane, and the First Point of Aries as the origin of longitude. The angle is measured counterclockwise from the First Point of Aries to the node, the angle is measured eastwards from north to the node. pp.40,72,137, chap. In the case of a star known only from visual observations, it is not possible to tell which node is ascending. In this case the orbital parameter which is recorded is the longitude of the node, Ω, here, n=<nx, ny, nz> is a vector pointing towards the ascending node. The reference plane is assumed to be the xy-plane, and the origin of longitude is taken to be the positive x-axis, K is the unit vector, which is the normal vector to the xy reference plane. For non-inclined orbits, Ω is undefined, for computation it is then, by convention, set equal to zero, that is, the ascending node is placed in the reference direction, which is equivalent to letting n point towards the positive x-axis. Kepler orbits Equinox Orbital node perturbation of the plane can cause revolution of the ascending node
13.
Argument of periapsis
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The argument of periapsis, symbolized as ω, is one of the orbital elements of an orbiting body. Parametrically, ω is the angle from the ascending node to its periapsis. For specific types of orbits, words such as perihelion, perigee, periastron, an argument of periapsis of 0° means that the orbiting body will be at its closest approach to the central body at the same moment that it crosses the plane of reference from South to North. An argument of periapsis of 90° means that the body will reach periapsis at its northmost distance from the plane of reference. Adding the argument of periapsis to the longitude of the ascending node gives the longitude of the periapsis, however, especially in discussions of binary stars and exoplanets, the terms longitude of periapsis or longitude of periastron are often used synonymously with argument of periapsis. In the case of equatorial orbits, the argument is strictly undefined, where, ex and ey are the x- and y-components of the eccentricity vector e. In the case of circular orbits it is assumed that the periapsis is placed at the ascending node. Kepler orbit Orbital mechanics Orbital node
14.
Mean anomaly
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In celestial mechanics, the mean anomaly is an angle used in calculating the position of a body in an elliptical orbit in the classical two-body problem. Define T as the time required for a body to complete one orbit. In time T, the radius vector sweeps out 2π radians or 360°. The average rate of sweep, n, is then n =2 π T or n =360 ∘ T, define τ as the time at which the body is at the pericenter. From the above definitions, a new quantity, M, the mean anomaly can be defined M = n, because the rate of increase, n, is a constant average, the mean anomaly increases uniformly from 0 to 2π radians or 0° to 360° during each orbit. It is equal to 0 when the body is at the pericenter, π radians at the apocenter, if the mean anomaly is known at any given instant, it can be calculated at any later instant by simply adding n δt where δt represents the time difference. Mean anomaly does not measure an angle between any physical objects and it is simply a convenient uniform measure of how far around its orbit a body has progressed since pericenter. The mean anomaly is one of three parameters that define a position along an orbit, the other two being the eccentric anomaly and the true anomaly. Define l as the longitude, the angular distance of the body from the same reference direction. Thus mean anomaly is also M = l − ϖ, mean angular motion can also be expressed, n = μ a 3, where μ is a gravitational parameter which varies with the masses of the objects, and a is the semi-major axis of the orbit. Mean anomaly can then be expanded, M = μ a 3, and here mean anomaly represents uniform angular motion on a circle of radius a
15.
Satellite
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In the context of spaceflight, a satellite is an artificial object which has been intentionally placed into orbit. Such objects are called artificial satellites to distinguish them from natural satellites such as Earths Moon. In 1957 the Soviet Union launched the worlds first artificial satellite, since then, about 6,600 satellites from more than 40 countries have been launched. According to a 2013 estimate,3,600 remained in orbit, of those, about 1,000 were operational, the rest have lived out their useful lives and become space debris. Approximately 500 operational satellites are in orbit,50 are in medium-Earth orbit. A few large satellites have been launched in parts and assembled in orbit. Over a dozen space probes have been placed into orbit around other bodies and become artificial satellites to the Moon, Mercury, Venus, Mars, Jupiter, Saturn, a few asteroids, Satellites are used for many purposes. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, Space stations and human spacecraft in orbit are also satellites. Satellite orbits vary greatly, depending on the purpose of the satellite, well-known classes include low Earth orbit, polar orbit, and geostationary orbit. A launch vehicle is a rocket that throws a satellite into orbit, usually it lifts off from a launch pad on land. Some are launched at sea from a submarine or a mobile maritime platform, Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control, the first fictional depiction of a satellite being launched into orbit was a short story by Edward Everett Hale, The Brick Moon. The idea surfaced again in Jules Vernes The Begums Fortune, in 1903, Konstantin Tsiolkovsky published Exploring Space Using Jet Propulsion Devices, which is the first academic treatise on the use of rocketry to launch spacecraft. He calculated the speed required for a minimal orbit. In 1928, Herman Potočnik published his book, The Problem of Space Travel — The Rocket Motor. He described the use of orbiting spacecraft for observation of the ground, in a 1945 Wireless World article, the English science fiction writer Arthur C. Clarke described in detail the possible use of communications satellites for mass communications. He suggested that three geostationary satellites would provide coverage over the entire planet, the first artificial satellite was Sputnik 1, launched by the Soviet Union on October 4,1957, and initiating the Soviet Sputnik program, with Sergei Korolev as chief designer. This in turn triggered the Space Race between the Soviet Union and the United States, Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital change and provided data on radio-signal distribution in the ionosphere
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Sun-synchronous orbit
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A Sun-synchronous orbit is a geocentric orbit that combines altitude and inclination in such a way that the satellite passes over any given point of the planets surface at the same local solar time. Such an orbit can place a satellite in constant sunlight and is useful for imaging, spy, more technically, it is an orbit arranged in such a way that it precesses once a year. The surface illumination angle will be nearly the same time that the satellite is overhead. This consistent lighting is a characteristic for satellites that image the Earths surface in visible or infrared wavelengths. For example, a satellite in sun-synchronous orbit might ascend across the twelve times a day each time at approximately 15,00 mean local time. This is achieved by having the orbital plane precess approximately one degree each day with respect to the celestial sphere, eastward. Typical sun-synchronous orbits are about 600–800 km in altitude, with periods in the 96–100 minute range, riding the terminator is useful for active radar satellites as the satellites solar panels can always see the Sun, without being shadowed by the Earth. The dawn/dusk orbit has been used for solar observing scientific satellites such as Yohkoh, TRACE, Hinode and PROBA2, Sun-synchronous orbits can happen around other oblate planets, such as Mars. A satellite around the almost spherical Venus, for example, will need an outside push to be in a sun-synchronous orbit.696 deg. Note that according to this approximation cos i equals −1 when the semi-major axis equals 12352 km, the period can be in the range from 88 minutes for a very low orbit to 3.8 hours. If one wants a satellite to fly over some given spot on Earth every day at the same hour, it can do between 7 and 16 orbits per day, as shown in the following table. When one says that a Sun-synchronous orbit goes over a spot on the earth at the local time each time. The Sun will not be in exactly the same position in the sky during the course of the year, very often a frozen orbit is therefore selected that is slightly higher over the Southern hemisphere than over the Northern hemisphere. ERS-1, ERS-2 and Envisat of European Space Agency as well as the MetOp spacecraft of EUMETSAT are all operated in Sun-synchronous, orbital perturbation analysis Analemma Geosynchronous orbit Geostationary orbit List of orbits Polar orbit World Geodetic System Sandwell, David T. The Gravity Field of the Earth - Part 1 Sun-Synchronous Orbit dictionary entry, centennial of Flight Commission NASA Q&A Boain, Ronald J. The A-B-Cs of Sun Synchronous Orbit Design, List of satellites in Sun-synchronous orbit
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Orbit
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In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet about a star or a natural satellite around a planet. Normally, orbit refers to a regularly repeating path around a body, to a close approximation, planets and satellites follow elliptical orbits, with the central mass being orbited at a focal point of the ellipse, as described by Keplers laws of planetary motion. For ease of calculation, in most situations orbital motion is adequately approximated by Newtonian Mechanics, historically, the apparent motions of the planets were described by European and Arabic philosophers using the idea of celestial spheres. This model posited the existence of perfect moving spheres or rings to which the stars and it assumed the heavens were fixed apart from the motion of the spheres, and was developed without any understanding of gravity. After the planets motions were accurately measured, theoretical mechanisms such as deferent. Originally geocentric it was modified by Copernicus to place the sun at the centre to help simplify the model, the model was further challenged during the 16th century, as comets were observed traversing the spheres. The basis for the understanding of orbits was first formulated by Johannes Kepler whose results are summarised in his three laws of planetary motion. Second, he found that the speed of each planet is not constant, as had previously been thought. Third, Kepler found a relationship between the orbital properties of all the planets orbiting the Sun. For the planets, the cubes of their distances from the Sun are proportional to the squares of their orbital periods. Jupiter and Venus, for example, are respectively about 5.2 and 0.723 AU distant from the Sun, their orbital periods respectively about 11.86 and 0.615 years. The proportionality is seen by the fact that the ratio for Jupiter,5. 23/11.862, is equal to that for Venus,0. 7233/0.6152. Idealised orbits meeting these rules are known as Kepler orbits, isaac Newton demonstrated that Keplers laws were derivable from his theory of gravitation and that, in general, the orbits of bodies subject to gravity were conic sections. Newton showed that, for a pair of bodies, the sizes are in inverse proportion to their masses. Where one body is more massive than the other, it is a convenient approximation to take the center of mass as coinciding with the center of the more massive body. Lagrange developed a new approach to Newtonian mechanics emphasizing energy more than force, in a dramatic vindication of classical mechanics, in 1846 le Verrier was able to predict the position of Neptune based on unexplained perturbations in the orbit of Uranus. This led astronomers to recognize that Newtonian mechanics did not provide the highest accuracy in understanding orbits, in relativity theory, orbits follow geodesic trajectories which are usually approximated very well by the Newtonian predictions but the differences are measurable. Essentially all the evidence that can distinguish between the theories agrees with relativity theory to within experimental measurement accuracy
18.
Earth
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Earth, otherwise known as the World, or the Globe, is the third planet from the Sun and the only object in the Universe known to harbor life. It is the densest planet in the Solar System and the largest of the four terrestrial planets, according to radiometric dating and other sources of evidence, Earth formed about 4.54 billion years ago. Earths gravity interacts with objects in space, especially the Sun. During one orbit around the Sun, Earth rotates about its axis over 365 times, thus, Earths axis of rotation is tilted, producing seasonal variations on the planets surface. The gravitational interaction between the Earth and Moon causes ocean tides, stabilizes the Earths orientation on its axis, Earths lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years. About 71% of Earths surface is covered with water, mostly by its oceans, the remaining 29% is land consisting of continents and islands that together have many lakes, rivers and other sources of water that contribute to the hydrosphere. The majority of Earths polar regions are covered in ice, including the Antarctic ice sheet, Earths interior remains active with a solid iron inner core, a liquid outer core that generates the Earths magnetic field, and a convecting mantle that drives plate tectonics. Within the first billion years of Earths history, life appeared in the oceans and began to affect the Earths atmosphere and surface, some geological evidence indicates that life may have arisen as much as 4.1 billion years ago. Since then, the combination of Earths distance from the Sun, physical properties, in the history of the Earth, biodiversity has gone through long periods of expansion, occasionally punctuated by mass extinction events. Over 99% of all species that lived on Earth are extinct. Estimates of the number of species on Earth today vary widely, over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival. Humans have developed diverse societies and cultures, politically, the world has about 200 sovereign states, the modern English word Earth developed from a wide variety of Middle English forms, which derived from an Old English noun most often spelled eorðe. It has cognates in every Germanic language, and their proto-Germanic root has been reconstructed as *erþō, originally, earth was written in lowercase, and from early Middle English, its definite sense as the globe was expressed as the earth. By early Modern English, many nouns were capitalized, and the became the Earth. More recently, the name is simply given as Earth. House styles now vary, Oxford spelling recognizes the lowercase form as the most common, another convention capitalizes Earth when appearing as a name but writes it in lowercase when preceded by the. It almost always appears in lowercase in colloquial expressions such as what on earth are you doing, the oldest material found in the Solar System is dated to 4. 5672±0.0006 billion years ago. By 4. 54±0.04 Gya the primordial Earth had formed, the formation and evolution of Solar System bodies occurred along with the Sun
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Latin
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Latin is a classical language belonging to the Italic branch of the Indo-European languages. The Latin alphabet is derived from the Etruscan and Greek alphabets, Latin was originally spoken in Latium, in the Italian Peninsula. Through the power of the Roman Republic, it became the dominant language, Vulgar Latin developed into the Romance languages, such as Italian, Portuguese, Spanish, French, and Romanian. Latin, Italian and French have contributed many words to the English language, Latin and Ancient Greek roots are used in theology, biology, and medicine. By the late Roman Republic, Old Latin had been standardised into Classical Latin, Vulgar Latin was the colloquial form spoken during the same time and attested in inscriptions and the works of comic playwrights like Plautus and Terence. Late Latin is the language from the 3rd century. Later, Early Modern Latin and Modern Latin evolved, Latin was used as the language of international communication, scholarship, and science until well into the 18th century, when it began to be supplanted by vernaculars. Ecclesiastical Latin remains the language of the Holy See and the Roman Rite of the Catholic Church. Today, many students, scholars and members of the Catholic clergy speak Latin fluently and it is taught in primary, secondary and postsecondary educational institutions around the world. The language has been passed down through various forms, some inscriptions have been published in an internationally agreed, monumental, multivolume series, the Corpus Inscriptionum Latinarum. Authors and publishers vary, but the format is about the same, volumes detailing inscriptions with a critical apparatus stating the provenance, the reading and interpretation of these inscriptions is the subject matter of the field of epigraphy. The works of several hundred ancient authors who wrote in Latin have survived in whole or in part and they are in part the subject matter of the field of classics. The Cat in the Hat, and a book of fairy tales, additional resources include phrasebooks and resources for rendering everyday phrases and concepts into Latin, such as Meissners Latin Phrasebook. The Latin influence in English has been significant at all stages of its insular development. From the 16th to the 18th centuries, English writers cobbled together huge numbers of new words from Latin and Greek words, dubbed inkhorn terms, as if they had spilled from a pot of ink. Many of these words were used once by the author and then forgotten, many of the most common polysyllabic English words are of Latin origin through the medium of Old French. Romance words make respectively 59%, 20% and 14% of English, German and those figures can rise dramatically when only non-compound and non-derived words are included. Accordingly, Romance words make roughly 35% of the vocabulary of Dutch, Roman engineering had the same effect on scientific terminology as a whole
20.
Natural environment
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The natural environment encompasses all living and non-living things occurring naturally. The term is most often applied to the Earth or some part of Earth and this environment encompasses the interaction of all living species, climate, weather, and natural resources that affect human survival and economic activity. Even acts which seem less extreme, such as building a mud hut or a system in the desert. Though many animals build things to provide an environment for themselves, they are not human, hence beaver dams. People seldom find absolutely natural environments on Earth, and naturalness usually varies in a continuum, more precisely, we can consider the different aspects or components of an environment, and see that their degree of naturalness is not uniform. If, for instance, in a field, the mineralogic composition and the structure of its soil are similar to those of an undisturbed forest soil. Natural environment is used as a synonym for habitat. For instance, when we say that the environment of giraffes is the savanna. Earth science generally recognizes 4 spheres, the lithosphere, the hydrosphere, the atmosphere, and the biosphere as correspondent to rocks, water, air, and life respectively. Some scientists include, as part of the spheres of the Earth, Earth science, is an all-embracing term for the sciences related to the planet Earth. There are four major disciplines in sciences, namely geography, geology, geophysics. These major disciplines use physics, chemistry, biology, chronology, the Earths crust, or lithosphere, is the outermost solid surface of the planet and is chemically and mechanically different from underlying mantle. It has been generated greatly by igneous processes in which magma cools, beneath the lithosphere lies the mantle which is heated by the decay of radioactive elements. The mantle though solid is in a state of rheic convection and this convection process causes the lithospheric plates to move, albeit slowly. The resulting process is known as plate tectonics, volcanoes result primarily from the melting of subducted crust material or of rising mantle at mid-ocean ridges and mantle plumes. An ocean is a body of saline water, and a component of the hydrosphere. Approximately 71% of the Earths surface is covered by ocean, a body of water that is customarily divided into several principal oceans. More than half of area is over 3,000 meters deep
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Climate
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Climate is the statistics of weather, usually over a 30-year interval. Climate differs from weather, in that weather only describes the conditions of these variables in a given region. A regions climate is generated by the system, which has five components, atmosphere, hydrosphere, cryosphere, lithosphere. The climate of a location is affected by its latitude, terrain, climates can be classified according to the average and the typical ranges of different variables, most commonly temperature and precipitation. The most commonly used classification scheme was the Köppen climate classification, the Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region. Paleoclimatology is the study of ancient climates, Climate models are mathematical models of past, present and future climates. Climate change may occur long and short timescales from a variety of factors. For example, a 3°C change in mean annual temperature corresponds to a shift in isotherms of approximately 300–400 km in latitude or 500 m in elevation, therefore, species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones. Climate is commonly defined as the weather averaged over a long period, the standard averaging period is 30 years, but other periods may be used depending on the purpose. Climate also includes statistics other than the average, such as the magnitudes of day-to-day or year-to-year variations, the classical period is 30 years, as defined by the World Meteorological Organization. These quantities are most often surface variables such as temperature, precipitation, Climate in a wider sense is the state, including a statistical description, of the climate system. The World Meteorological Organization describes climate normals as reference points used by climatologists to compare current climatological trends to that of the past or what is considered normal, a Normal is defined as the arithmetic average of a climate element over a 30-year period. A30 year period is used, as it is enough to filter out any interannual variation or anomalies. The WMO originated from the International Meteorological Organization which set up a commission for climatology in 1929. At its 1934 Wiesbaden meeting the commission designated the thirty-year period from 1901 to 1930 as the reference time frame for climatological standard normals. In 1982 the WMO agreed to update climate normals, and in these were completed on the basis of climate data from 1 January 1961 to 31 December 1990. The difference between climate and weather is usefully summarized by the popular phrase Climate is what you expect, weather is what you get. Over historical time spans there are a number of nearly constant variables that determine climate, including latitude, altitude, proportion of land to water and these change only over periods of millions of years due to processes such as plate tectonics
22.
Clouds and the Earth's Radiant Energy System
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Clouds and the Earths Radiant Energy System is on-going NASA climatological experiment from Earth orbit. Cloud properties are determined using simultaneous measurements by other EOS instruments such as the Moderate Resolution Imaging Spectroradiometer, CERES experiment has four main objectives, Continuation of the ERBE record of radiative fluxes at the top of the atmosphere for climate change analysis. Doubling the accuracy of estimates of radiative fluxes at TOA and the Earths surface, provide the first long-term global estimates of the radiative fluxes within the Earths atmosphere. Provide cloud property estimates that are consistent with the radiative fluxes from surface to TOA, the CERES instrument was based on the successful Earth Radiation Budget Experiment which used three satellites to provide global energy budget measurements from 1984 to 1993. CERES spatial resolution at nadir view is 10 km for CERES on TRMM, onboard calibration sources for channels measuring reflected sunlight include solar diffusers and tungsten lamps. A pair of blackbody cavities that can be controlled at different temperatures are used for the Total, cold space observations and internal calibration are performed during normal Earth scans. The first CERES instrument was launched aboard the NASA Tropical Rainfall Measuring Mission in November 1997 from Japan, however, this instrument failed to operate after 8 months due to an on-board circuit failure. An additional four CERES instruments were launched on the Earth Observing System Terra satellite in December 1999, a fifth instrument is on the Suomi NPP satellite. Currently operational are all CERES instruments on Terra and Aqua satellites, the FM6 instrument is to be launched on the JPSS-1 spacecraft in 2017. CERES operates in three scanning modes, across the ground track, along the direction of the satellite ground track. In RAP mode, the radiometers scan in elevation as they rotate in azimuth, until February 2005, on Terra and Aqua satellites one of CERES instruments scanned in cross-track mode while the other was in RAP or along-track mode. The instrument operating in RAP scanning mode took two days of data every month. However the multi-angular CERES data allowed to derive new models which account for anisotropy of the viewed scene, Earths energy budget Radiometry Remote sensing NASA CERES official site CERES Data Products Terra satellite, NASA EOS flagship Aqua satallite, NASA EOS VISIBLE EARTH, catalog of CERES images
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Moderate-resolution imaging spectroradiometer
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The instruments capture data in 36 spectral bands ranging in wavelength from 0.4 µm to 14.4 µm and at varying spatial resolutions. Together the instruments image the entire Earth every 1 to 2 days, MODIS has used the marine optical buoy for vicarious calibration. MODIS is succeeded by the VIIRS instrument on board the Suomi NPP satellite launched in 2011, the MODIS characterization support team is dedicated to the production of high-quality MODIS calibrated product which is a precursor to every geophysical science product. A detailed description of the MCST mission statement and other details can be found at MCST Web, with its low spatial resolution but high temporal resolution, MODIS data is useful to track changes in the landscape over time. The United States Forest Services Remote Sensing Applications Center analyzes MODIS imagery on a basis to provide information for the management. The following MODIS Level 3 datasets are available from NASA, as processed by the Collection 5 software, most of the data is available in the HDF-EOS format — a variant of Hierarchical Data Format prescribed for the data derived from Earth Observing System missions. Imaging spectroscopy NASA World Wind Official NASA site MODIS bands and spectral ranges MODIS Images of the Day MODIS Image of the Day – Google Gadget referring to MODIS image of the day
24.
MOPITT
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MOPITT is a payload scientific instrument launched into Earth orbit by NASA on board the Terra satellite in 1999. It is designed to monitor changes in patterns and its effect in the lower atmosphere of the Earth. The instrument was funded by the Space Science Division of the Canadian Space Agency, MOPITT is a nadir sounding instrument which measures upwelling infrared radiation at 4.7 μm and 2. 2-2.4 μm. It uses correlation spectroscopy to calculate total column observations and profiles of carbon monoxide in the lower atmosphere, although observations of methane were also planned, to date no data have been released. The measurements of pollution in the instrument, Overall performance. Journal of Atmospheric and Oceanic Technology, transport of carbon monoxide from the tropics to the extratropics. Official website for MOPITT science and product development team MOPITT instrument website at the University of Toronto NASA WIST data archive system MOPITT data available through NASA-Langley
25.
Aerosol
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An aerosol is a colloid of fine solid particles or liquid droplets, in air or another gas. Aerosols can be natural or artificial, examples of natural aerosols are fog, forest exudates and geyser steam. Examples of artificial aerosols are haze, dust, particulate air pollutants, the liquid or solid particles have diameter mostly smaller than 1 μm or so, larger particles with a significant settling speed make the mixture a suspension, but the distinction is not clear-cut. In general conversation, aerosol refers to an aerosol spray that delivers a consumer product from a can or similar container. Other technological applications of aerosols include dispersal of pesticides, medical treatment of respiratory illnesses, diseases can also spread by means of small droplets in the breath, also called aerosols. Aerosol science covers generation and removal of aerosols, technological application of aerosols, effects of aerosols on the environment and people, an aerosol is defined as a colloidal system of solid or liquid particles in a gas. An aerosol includes both the particles and the gas, which is usually air. Frederick G. Donnan presumably first used the term aerosol during World War I to describe an aero-solution and this term developed analogously to the term hydrosol, a colloid system with water as the dispersing medium. Primary aerosols contain particles introduced directly into the gas, secondary aerosols form through gas-to-particle conversion, various types of aerosol, classified according to physical form and how they were generated, include dust, fume, mist, smoke and fog. There are several measures of aerosol concentration, Environmental science and health often uses the mass concentration, defined as the mass of particulate matter per unit volume with units such as μg/m3. Also commonly used is the concentration, the number of particles per unit volume with units such as number/m3 or number/cm3. The size of particles has an influence on their properties. A monodisperse aerosol, producible in the laboratory, contains particles of uniform size, most aerosols, however, as polydisperse colloidal systems, exhibit a range of particle sizes. Liquid droplets are almost always nearly spherical, but scientists use an equivalent diameter to characterize the properities of various shapes of solid particles, the equivalent diameter is the diameter of a spherical particle with the same value of some physical property as the irregular particle. The equivalent volume diameter is defined as the diameter of a sphere of the volume as that of the irregular particle. Also commonly used is the aerodynamic diameter, for a monodisperse aerosol, a single number—the particle diameter—suffices to describe the size of the particles. However, more complicated particle-size distributions describe the sizes of the particles in a polydisperse aerosol and this distribution defines the relative amounts of particles, sorted according to size. One approach to defining the size distribution uses a list of the sizes of every particle in a sample
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Solar eclipse of August 1, 2008
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A total solar eclipse occurred on August 1,2008. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. A total solar eclipse occurs when the Moons apparent diameter is larger than the Suns, blocking all direct sunlight, totality occurs in a narrow path across Earths surface, with the partial solar eclipse visible over a surrounding region thousands of kilometres wide. It had a magnitude of 1.0394 that was visible from a corridor through northern Canada, Greenland, central Russia, eastern Kazakhstan, western Mongolia. Occurring north of the circle, it belonged to the so-called midnight sun eclipses. The largest city on the path of the eclipse was Novosibirsk in Russia, the total eclipse lasted for 2 minutes, and covered 0. 4% of the Earths surface in a 10,200 km long path. It was the 47th eclipse of the 126th Saros cycle, which began with an eclipse on March 10,1179. A partial eclipse could be seen from the much broader path of the Moons penumbra, including northeastern North America and most of Europe and it was described by observers as special for its colours around the horizon. There were wonderful oranges and reds all around, the lit up, some dark in silhouette, some golden. The path of the eclipse then headed north-east, crossing over northern Greenland, the path of totality touched the northeast corner of Kvitøya, an uninhabited Norwegian island in the Svalbard archipelago, at 09,47 UT. The eclipse reached the Russian mainland at 10,10 UT, with a path 232 km wide and a duration of 2 minutes 26 seconds. The greatest eclipse occurred shortly after, at 10,21,07 UT at coordinates 65°39′N 72°18′E, when the path was 237 km wide, cities in the path of the total eclipse included Megion, Nizhnevartovsk, Strezhevoy, Novosibirsk and Barnaul. Around 10,000 tourists were present in Novosibirsk, the largest city to experience the eclipse, the path of the eclipse then moved south-east, crossing into Mongolia and just clipping Kazakhstan at around 10,58 UT. The path here was 252 km wide, but the duration was decreased to 2 minutes 10 seconds, the path then ran down the China-Mongolia border, ending in China at 11,18 UT, with an eclipse lasting 1 minute 27 seconds at sunset. The total eclipse finished at 11,21 UT, the total eclipse passed over Yiwu County, Jiuquan and Xi’an. Around 10,000 people were gathered to watch the eclipse in Yiwu, a partial eclipse was seen from the much broader path of the Moons penumbra, including the north east coast of North America and most of Europe and Asia. In London, England, the eclipse began at 09,33 BST, with a maximum eclipse of 12% at 10,18 BST. At Edinburgh the partial eclipse was 23. 5% of the sun, german charter airline LTU, now trading as Air Berlin, operated a special flight from Düsseldorf to the North Pole to observe the eclipse
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Russia
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Russia, also officially the Russian Federation, is a country in Eurasia. The European western part of the country is more populated and urbanised than the eastern. Russias capital Moscow is one of the largest cities in the world, other urban centers include Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod. Extending across the entirety of Northern Asia and much of Eastern Europe, Russia spans eleven time zones and incorporates a range of environments. It shares maritime borders with Japan by the Sea of Okhotsk, the East Slavs emerged as a recognizable group in Europe between the 3rd and 8th centuries AD. Founded and ruled by a Varangian warrior elite and their descendants, in 988 it adopted Orthodox Christianity from the Byzantine Empire, beginning the synthesis of Byzantine and Slavic cultures that defined Russian culture for the next millennium. Rus ultimately disintegrated into a number of states, most of the Rus lands were overrun by the Mongol invasion. The Soviet Union played a role in the Allied victory in World War II. The Soviet era saw some of the most significant technological achievements of the 20th century, including the worlds first human-made satellite and the launching of the first humans in space. By the end of 1990, the Soviet Union had the second largest economy, largest standing military in the world. It is governed as a federal semi-presidential republic, the Russian economy ranks as the twelfth largest by nominal GDP and sixth largest by purchasing power parity in 2015. Russias extensive mineral and energy resources are the largest such reserves in the world, making it one of the producers of oil. The country is one of the five recognized nuclear weapons states and possesses the largest stockpile of weapons of mass destruction, Russia is a great power as well as a regional power and has been characterised as a potential superpower. The name Russia is derived from Rus, a state populated mostly by the East Slavs. However, this name became more prominent in the later history, and the country typically was called by its inhabitants Русская Земля. In order to distinguish this state from other states derived from it, it is denoted as Kievan Rus by modern historiography, an old Latin version of the name Rus was Ruthenia, mostly applied to the western and southern regions of Rus that were adjacent to Catholic Europe. The current name of the country, Россия, comes from the Byzantine Greek designation of the Kievan Rus, the standard way to refer to citizens of Russia is Russians in English and rossiyane in Russian. There are two Russian words which are translated into English as Russians
28.
Norway
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The Antarctic Peter I Island and the sub-Antarctic Bouvet Island are dependent territories and thus not considered part of the Kingdom. Norway also lays claim to a section of Antarctica known as Queen Maud Land, until 1814, the kingdom included the Faroe Islands, Greenland, and Iceland. It also included Isle of Man until 1266, Shetland and Orkney until 1468, Norway has a total area of 385,252 square kilometres and a population of 5,258,317. The country shares a long border with Sweden. Norway is bordered by Finland and Russia to the north-east, Norway has an extensive coastline, facing the North Atlantic Ocean and the Barents Sea. King Harald V of the Dano-German House of Glücksburg is the current King of Norway, erna Solberg became Prime Minister in 2013, replacing Jens Stoltenberg. A constitutional monarchy, Norway divides state power between the Parliament, the Cabinet and the Supreme Court, as determined by the 1814 Constitution, the kingdom is established as a merger of several petty kingdoms. By the traditional count from the year 872, the kingdom has existed continuously for 1,144 years, Norway has both administrative and political subdivisions on two levels, counties and municipalities. The Sámi people have an amount of self-determination and influence over traditional territories through the Sámi Parliament. Norway maintains close ties with the European Union and the United States, the country maintains a combination of market economy and a Nordic welfare model with universal health care and a comprehensive social security system. Norway has extensive reserves of petroleum, natural gas, minerals, lumber, seafood, the petroleum industry accounts for around a quarter of the countrys gross domestic product. On a per-capita basis, Norway is the worlds largest producer of oil, the country has the fourth-highest per capita income in the world on the World Bank and IMF lists. On the CIAs GDP per capita list which includes territories and some regions, from 2001 to 2006, and then again from 2009 to 2017, Norway had the highest Human Development Index ranking in the world. It also has the highest inequality-adjusted ranking, Norway ranks first on the World Happiness Report, the OECD Better Life Index, the Index of Public Integrity and the Democracy Index. Norway has two names, Noreg in Nynorsk and Norge in Bokmål. The name Norway comes from the Old English word Norðrveg mentioned in 880, meaning way or way leading to the north. In contrasting with suðrvegar southern way for Germany, and austrvegr eastern way for the Baltic, the Anglo-Saxon of Britain also referred to the kingdom of Norway in 880 as Norðmanna land. This was the area of Harald Fairhair, the first king of Norway, and because of him
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Arctic Ocean
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The Arctic Ocean is the smallest and shallowest of the worlds five major oceans. Alternatively, the Arctic Ocean can be seen as the northernmost part of the all-encompassing World Ocean, located mostly in the Arctic north polar region in the middle of the Northern Hemisphere, the Arctic Ocean is almost completely surrounded by Eurasia and North America. It is partly covered by sea ice throughout the year and almost completely in winter, the summer shrinking of the ice has been quoted at 50%. The US National Snow and Ice Data Center uses satellite data to provide a record of Arctic sea ice cover. The Arctic may become ice free for the first time in human history within a few years or by 2040, for much of European history, the north polar regions remained largely unexplored and their geography conjectural. He was probably describing loose sea ice known today as growlers or bergy bits, his Thule was probably Norway, early cartographers were unsure whether to draw the region around the North Pole as land or water. The makers of navigational charts, more conservative than some of the more fanciful cartographers, tended to leave the region blank and this lack of knowledge of what lay north of the shifting barrier of ice gave rise to a number of conjectures. In England and other European nations, the myth of an Open Polar Sea was persistent, john Barrow, longtime Second Secretary of the British Admiralty, promoted exploration of the region from 1818 to 1845 in search of this. In the United States in the 1850s and 1860s, the explorers Elisha Kane, even quite late in the century, the eminent authority Matthew Fontaine Maury included a description of the Open Polar Sea in his textbook The Physical Geography of the Sea. Nevertheless, as all the explorers who travelled closer and closer to the reported, the polar ice cap is quite thick. Fridtjof Nansen was the first to make a crossing of the Arctic Ocean. The first surface crossing of the ocean was led by Wally Herbert in 1969, in a dog sled expedition from Alaska to Svalbard, with air support. The first nautical transit of the pole was made in 1958 by the submarine USS Nautilus. Since 1937, Soviet and Russian manned drifting ice stations have extensively monitored the Arctic Ocean, scientific settlements were established on the drift ice and carried thousands of kilometres by ice floes. In World War II, the European region of the Arctic Ocean was heavily contested, the Arctic Ocean occupies a roughly circular basin and covers an area of about 14,056,000 km2, almost the size of Antarctica. The coastline is 45,390 km long and it is surrounded by the land masses of Eurasia, North America, Greenland, and by several islands. It is connected to the Pacific Ocean by the Bering Strait and to the Atlantic Ocean through the Greenland Sea, countries bordering the Arctic Ocean are, Russia, Norway, Iceland, Greenland, Canada and the United States. There are several ports and harbours around the Arctic Ocean In Alaska, in Canada, ships may anchor at Churchill in Manitoba, Nanisivik in Nunavut, Tuktoyaktuk or Inuvik in the Northwest territories
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Great Britain
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Great Britain, also known as Britain, is a large island in the north Atlantic Ocean off the northwest coast of continental Europe. With an area of 209,331 km2, Great Britain is the largest European island, in 2011 the island had a population of about 61 million people, making it the worlds third-most populous island after Java in Indonesia and Honshu in Japan. The island of Ireland is situated to the west of it, the island is dominated by a maritime climate with quite narrow temperature differences between seasons. Politically, the island is part of the United Kingdom of Great Britain and Northern Ireland, most of England, Scotland, and Wales are on the island. The term Great Britain often extends to surrounding islands that form part of England, Scotland, and Wales. A single Kingdom of Great Britain resulted from the union of the Kingdom of England, the archipelago has been referred to by a single name for over 2000 years, the term British Isles derives from terms used by classical geographers to describe this island group. By 50 BC Greek geographers were using equivalents of Prettanikē as a name for the British Isles. However, with the Roman conquest of Britain the Latin term Britannia was used for the island of Great Britain, the oldest mention of terms related to Great Britain was by Aristotle, or possibly by Pseudo-Aristotle, in his text On the Universe, Vol. III. To quote his works, There are two large islands in it, called the British Isles, Albion and Ierne. The name Britain descends from the Latin name for Britain, Britannia or Brittānia, Old French Bretaigne and Middle English Bretayne, Breteyne. The French form replaced the Old English Breoton, Breoten, Bryten, Breten, Britannia was used by the Romans from the 1st century BC for the British Isles taken together. It is derived from the writings of the Pytheas around 320 BC. Marcian of Heraclea, in his Periplus maris exteri, described the group as αἱ Πρεττανικαὶ νῆσοι. The peoples of these islands of Prettanike were called the Πρεττανοί, Priteni is the source of the Welsh language term Prydain, Britain, which has the same source as the Goidelic term Cruithne used to refer to the early Brythonic-speaking inhabitants of Ireland. The latter were later called Picts or Caledonians by the Romans, the Greco-Egyptian scientist Ptolemy referred to the larger island as great Britain and to Ireland as little Britain in his work Almagest. The name Albion appears to have out of use sometime after the Roman conquest of Britain. After the Anglo-Saxon period, Britain was used as a term only. It was used again in 1604, when King James VI and I styled himself King of Great Brittaine, France, Great Britain refers geographically to the island of Great Britain, politically to England, Scotland and Wales in combination
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Deepwater Horizon oil spill
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The Deepwater Horizon oil spill began on April 20,2010, in the Gulf of Mexico on the BP-operated Macondo Prospect. The US Government estimated the total discharge at 4.9 million barrels, after several failed efforts to contain the flow, the well was declared sealed on September 19,2010. Reports in early 2012 indicated the site was still leaking. Due to the spill, along with adverse effects from the response and cleanup activities, extensive damage to marine and wildlife habitats and fishing. In Louisiana,4.9 million pounds of material was removed from the beaches in 2013. Oil cleanup crews worked four days a week on 55 miles of Louisiana shoreline throughout 2013. Oil continued to be found as far from the Macondo site as the waters off the Florida Panhandle and Tampa Bay, in 2013 it was reported that dolphins and other marine life continued to die in record numbers with infant dolphins dying at six times the normal rate. Numerous investigations explored the causes of the explosion and record-setting spill, notably, the U. S. governments September 2011 report pointed to defective cement on the well, faulting mostly BP, but also rig operator Transocean and contractor Halliburton. BP and the Department of Justice agreed to a record-setting $4.525 billion in fines, as of February 2013, criminal and civil settlements and payments to a trust fund had cost the company $42.2 billion. In September 2014, a U. S. District Court judge ruled that BP was primarily responsible for the oil spill because of its gross negligence and reckless conduct. In July 2015, BP agreed to pay $18.7 billion in fines, the Deepwater Horizon was a 10-year-old semi-submersible, mobile, floating, dynamically positioned drilling rig that could operate in waters up to 10,000 feet deep. Built by South Korean company Hyundai Heavy Industries and owned by Transocean, the rig operated under the Marshallese flag of convenience and it was drilling a deep exploratory well,18,360 feet below sea level, in approximately 5,100 feet of water. The well is situated in the Macondo Prospect in Mississippi Canyon Block 252 of the Gulf of Mexico, the Macondo well is located roughly 41 miles off the Louisiana coast. BP was the operator and principal developer of the Macondo Prospect with a 65% share, while 25% was owned by Anadarko Petroleum Corporation, and 10% by MOEX Offshore 2007, a unit of Mitsui. At the time,126 crew members were on board, seven BP employees,79 of Transocean, eleven missing workers were never found despite a three-day U. S. Coast Guard search operation and are believed to have died in the explosion. Ninety-four crew were rescued by lifeboat or helicopter,17 of whom were treated for injuries, the Deepwater Horizon sank on the morning of 22 April 2010. The oil leak was discovered on the afternoon of 22 April 2010 when an oil slick began to spread at the former rig site. The oil flowed for 87 days, BP originally estimated a flow rate of 1,000 to 5,000 barrels per day
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Hurricane Karl
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Hurricane Karl was the most destructive tropical cyclone on record to strike the Mexican state of Veracruz. It crossed the Caribbean and was upgraded to Tropical Storm Karl on September 14 and this marked the first known time that a major hurricane existed in the Bay of Campeche. As of September 23,22 people have been confirmed killed, insured losses from the storm are estimated at $206 million USD as of January 2011 while total losses equated to approximately $3.9 billion. The origins of Hurricane Karl were from the interaction between a trough and westward-tracking tropical wave. The trough—an elongated area of low pressure—emerged from an area of disorganized monsoonal convection just north of South America over the Windward Islands in early September. A few days later, the wave, which had departed the coast of Africa on September 1, approached the area, although the convection remained disassociated from the mean low feature, the overall wind circulation continued to become better defined at the surface. The development trend briefly became disrupted by September 13, however, conditions remained favorable for reorganization, and a small but consolidated circulation center developed by 2100 UTC September 14. With a predominant ridge anchored to its north along the Gulf of Mexico, supported by symmetrical upper-level outflow, the storm strengthened slowly over very high water temperatures in a low-shear environment. Karl subsequently made its landfall on the southeastern coast of Yucatán as a strong tropical storm early on September 15. As it moved inland, radar imagery from Belize depicted a developing eye, although the storm slowly weakened as it crossed the Yucatán, its cloud pattern remained well-organized, with a ring of deep convection surrounding an eye-like feature. Around 0400 UTC September 16, the center of Karl emerged into the Bay of Campeche as it slowed slightly, at the time, Karl co-existed with Hurricanes Igor and Julia, the first such occasion since 1998 with at least three simultaneous hurricanes in the North Atlantic. Recurving toward the southwest along the ridge, Karl became a Category 3 hurricane on September 17. Karl became the strongest hurricane ever observed in the Bay of Campeche upon attaining this intensity, despite a sudden increase in minimum central pressure, Karl retained its strength and moved ashore near Veracruz, Mexico as a major hurricane at 1645 UTC. Once inland, the storm rapidly weakened over the high terrain. Upon the formation of a cyclone, the government of Mexico issued a tropical storm warning for the east coast of the Yucatán Peninsula. Additionally, a storm watch was in place for the coast of northern Belize. At the threat of a storm, authorities in Honduras declared an alert for the entire country. El Cajón, a hydroelectric power plant located in western Honduras
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2010 Atlantic hurricane season
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The 2010 Atlantic hurricane season was the third most active Atlantic hurricane season on record, tying with the 1887,1995,2011, and 2012 Atlantic hurricane seasons. It had the most named storms since the 2005 season, in addition, the 2010 Atlantic hurricane season was more active than the years Pacific typhoon season, only the second time this is known to have occurred. Following Alex, a series of relatively weak systems occurred into the month of July and early August. In the latter part of August and September, the season much more active with the formation of eleven named storms in about 40 days. Four of those Cape Verde storms each reached Category 4 intensity, Danielle and Earl were back-to-back major hurricanes, followed by several weak tropical storms, and then another series of three consecutive major hurricanes. In the month of September, eight named storms formed, which is the highest ever recorded, in addition, there were three occasions when three tropical cyclones were active simultaneously, with the first set being Danielle, Earl, and Fiona co-existing on August 30 – August 31. The second occasion was when Earl, Fiona, and Gaston co-existed on September 1 – September 2, the third and most notable was when Igor, Julia, and Karl were active September 14 – September 18. During a brief period, on September 15, Igor and Julia were simultaneously Category 4 hurricanes. Both were still hurricanes when Karl was upgraded to a hurricane on September 16, in advance of, and during, each hurricane season, several forecasts of hurricane activity are issued by national meteorological services, scientific agencies, and noted hurricane experts. The forecasts include weekly and monthly changes in significant factors that determine the number of tropical storms, hurricanes. The organization referenced two main factors, slower trade winds across the Caribbean and above-average ocean temperatures across the Atlantic, for an above-average season. Two days later, Colorado State University issued their first extended range outlook, featuring 11 to 16 named storms,6 to 8 hurricanes,3 to 5 major hurricanes, and an ACE index of 100 to 162 units. Meanwhile, on January 27,2010, The Weather Company called for the year to feature 13 named storms,7 hurricanes, and 3 major hurricanes. CSU issued a detailed update on April 7, upping their forecast to 15 named storms,8 hurricanes,4 major hurricanes. More confidence in the weakening of El Niño and the continuation of anomalously warm sea surface temperatures across the Atlantic Ocean were cited. Two days later, TSR revised their forecast upward to 16.3 named storms,8.5 hurricanes,4 major hurricanes, and an ACE index of 159 units. In their April 21 update, WSI predicted the most active year since the record-breaking 2005 season, with 16 named storms,9 hurricanes, and 5 major hurricanes. Five days later, North Carolina State University released their only forecast for the season, TSR largely maintained their forecast for their May 25 release
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Aqua (satellite)
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Aqua is a multi-national NASA scientific research satellite in orbit around the Earth, studying the precipitation, evaporation, and cycling of water. It is the major component of the Earth Observing System preceded by Terra. The name Aqua comes from the Latin word for water, the satellite was launched from Vandenberg Air Force Base on May 4,2002, aboard a Delta II rocket. Aqua is on a Sun-synchronous orbit and it flies as the second in the satellite formation called the A Train with several other satellites. Furnished by the National Space Development Agency of Japan, MODIS — Moderate Resolution Imaging Spectroradiometer, also measures cloud properties and radiative energy flux, also aerosol properties, land cover and land use change, fires and volcanoes. This instrument is also aboard Terra, aMSU-A — Advanced Microwave Sounding Unit — measures atmospheric temperature and humidity. AIRS — Atmospheric Infrared Sounder — measures atmospheric temperature and humidity, land, HSB — Humidity Sounder for Brazil — VHF band equipment measuring atmospheric humidity. Furnished by Instituto Nacional de Pesquisas Espaciais of Brazil, the HSB instrument has been in survival mode since 2/5/2003. CERES — Clouds and the Earths Radiant Energy System, Flying Models 3 and 4, the Aqua spacecraft has a mass of about 2,850 kilograms, plus propellant of about 230 kilograms. Stowed, the satellite is 2.68 m x 2.49 m x 6.49 m. Deployed, Aqua is 4.81 m x 16.70 m x 8.04 m. Terra Aura NASA Aqua site Aqua Mission Profile by NASAs Solar System Exploration Mission Control Tunes Up Aquas Orbit, August 20,2009
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Aura (satellite)
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Aura is a multi-national NASA scientific research satellite in orbit around the Earth, studying the Earths ozone layer, air quality and climate. It is the major component of the Earth Observing System following on Terra. Aura follows on from the Upper Atmosphere Research Satellite, the name Aura comes from the Latin word for air. The satellite was launched from Vandenberg Air Force Base on July 15,2004, the Aura spacecraft has a mass of about 1,765 kg. The body is 6.9 m long with the extended single solar panel about 15 m long, Aura flies in a sun-synchronous orbit, in formation with 6 other satellites, collectively known as the A Train. The other satellites in the formation are, Aqua CALIPSO CloudSat GCOM-W1 OCO-2 PARASOL All satellites have an equatorial crossing time at about 1,30 in the afternoon, developed jointly with the United Kingdom Natural Environment Research Council. The HIRDLS chopper shutdown on March 17,2008, and has not produced science since, MLS — Microwave Limb Sounder — measures emissions from ozone, chlorine and other trace gases, and clarifies the role of water vapor in global warming. OMI — Ozone Monitoring Instrument — uses ultraviolet and visible radiation to produce daily high-resolution maps, developed by the Finnish Meteorological Institute and the Netherlands Agency for Aerospace Programmes. TES — Tropospheric Emission Spectrometer — measures tropospheric ozone in infrared wavelengths, also carbon monoxide, methane, Terra Aqua NASA site Aura validation data centre Aura Mission Profile by NASAs Solar System Exploration
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Man-made structures visible from space
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Man-made structures visible from earth orbit without magnification include highways, dams, and cities. The most commonly cited example, the Great Wall of China, is visible from low Earth orbit, and even then only under perfect conditions. Because of the square law, there are major differences in visibility from just above the Kármán line. From US Space Shuttles, which orbit at around 135 miles, cities are easily distinguishable from surrounding countryside. Using binoculars, astronauts could see roads, airports, dams, harbors, even large vehicles such as ships. Cities are also visible from the orbit of the ISS. Metropolitan areas are clear at night, particularly in industrialized countries, due to a multitude of street lights, the greenhouse complex that covers almost 50,000 acres in the province of Almería, Andalucía, Spain is visible from space. The claim that the Great Wall of China is the only man-made object visible from the moon or outer space has been debunked many times, but remains a common misconception in popular culture. According to astronauts Eugene Cernan and Ed Lu, the Great Wall is visible from the part of low Earth orbit. Different claims are made for the factoid that the Great Wall is visible from the Moon, william Stukeley mentioned this claim in his letter dated 1754, and Henry Norman made the same claim in 1895. The issue of canals on Mars was prominent in the late 19th century and may have led to the belief that long, a viewer would need visual acuity 17,000 times better than normal to see the Great Wall from the Moon. Trivia questions and urban legends often claim certain constructed objects or effects are so large they are visible from outer space, for example, a giant beaver dam in Canada was described as so large it is visible from outer space. Field and Stream, a Canadian Magazine, wrote, How big, Great Wall of China from space
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Remote sensing
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Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object and thus in contrast to on-site observation. It may be split into active remote sensing and passive remote sensing, passive sensors gather radiation that is emitted or reflected by the object or surrounding areas. Reflected sunlight is the most common source of radiation measured by passive sensors, examples of passive remote sensors include film photography, infrared, charge-coupled devices, and radiometers. Active collection, on the hand, emits energy in order to scan objects and areas whereupon a sensor then detects. RADAR and LiDAR are examples of remote sensing where the time delay between emission and return is measured, establishing the location, speed and direction of an object. Remote sensing makes it possible to data of dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as the Amazon Basin, glacial features in Arctic and Antarctic regions, military collection during the Cold War made use of stand-off collection of data about dangerous border areas. Remote sensing also replaces costly and slow data collection on the ground, the basis for multispectral collection and analysis is that of examined areas or objects that reflect or emit radiation that stand out from surrounding areas. For a summary of major remote sensing satellite systems see the overview table, conventional radar is mostly associated with aerial traffic control, early warning, and certain large scale meteorological data. Other types of active collection includes plasmas in the ionosphere, interferometric synthetic aperture radar is used to produce precise digital elevation models of large scale terrain. Laser and radar altimeters on satellites have provided a range of data. By measuring the bulges of water caused by gravity, they map features on the seafloor to a resolution of a mile or so, by measuring the height and wavelength of ocean waves, the altimeters measure wind speeds and direction, and surface ocean currents and directions. Ultrasound and radar tide gauges measure sea level, tides and wave direction in coastal, light detection and ranging is well known in examples of weapon ranging, laser illuminated homing of projectiles. Vegetation remote sensing is an application of LIDAR. Radiometers and photometers are the most common instrument in use, collecting reflected and emitted radiation in a range of frequencies. The most common are visible and infrared sensors, followed by microwave, gamma ray and rarely and they may also be used to detect the emission spectra of various chemicals, providing data on chemical concentrations in the atmosphere. Simultaneous multi-spectral platforms such as Landsat have been in use since the 1970s and these thematic mappers take images in multiple wavelengths of electro-magnetic radiation and are usually found on Earth observation satellites, including the Landsat program or the IKONOS satellite. Landsat images are used by agencies such as KYDOW to indicate water quality parameters including Secchi depth, chlorophyll a density
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Earth observation satellite
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Most Earth observation satellites carry instruments that should be operated at a relatively low altitude. Altitudes below 500-600 kilometers are in general avoided, though, because of the significant air-drag at such low altitudes making frequent orbit reboost maneuvres necessary. The Earth observation satellites ERS-1, ERS-2 and Envisat of European Space Agency as well as the MetOp spacecraft of EUMETSAT are all operated at altitudes of about 800 km. The Proba-1, Proba-2 and SMOS spacecraft of European Space Agency are observing the Earth from an altitude of about 700 km, the Earth observation satellites of UAE, DubaiSat-1 & DubaiSat-2 are also placed in Low Earth Orbits orbits and providing satellite imagery of various parts of the Earth. To get global coverage with a low orbit it must be a polar orbit or nearly so, spacecraft carrying instruments for which an altitude of 36000 km is suitable sometimes use a geostationary orbit. Such an orbit allows uninterrupted coverage of more than 1/3 of the Earth, three geostationary spacecraft at longitudes separated with 120 deg can cover the whole Earth except the extreme polar regions. This type of orbit is used for meteorological satellites. A weather satellite is a type of satellite that is used to monitor the weather. These meteorological satellites, however, see more than clouds and cloud systems, weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens and activity from other volcanoes such as Mount Etna. By monitoring vegetation changes over time, droughts can be monitored by comparing the current vegetation state to its long term average, anthropogenic emissions can be monitored by evaluating data of tropospheric NO2 and SO2. These types of satellites are almost always in Sun synchronous and frozen orbits, the Sun synchronous orbit is in general sufficiently close to polar to get the desired global coverage while the relatively constant geometry to the Sun mostly is an advantage for the instruments. The frozen orbit is selected as this is the closest to an orbit that is possible in the gravitational field of the Earth. Terrain can be mapped from space with the use of satellites, such as Radarsat-1 and TerraSAR-X. campevans. org/_CE/html/tiros1-2. html
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Geographic information system
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A geographic information system is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data. What goes beyond a GIS is a spatial data infrastructure, a concept that has no such restrictive boundaries, in general, the term describes any information system that integrates, stores, edits, analyzes, shares, and displays geographic information. GIS applications are tools that allow users to create interactive queries, analyze spatial information, edit data in maps, Geographic information science is the science underlying geographic concepts, applications, and systems. GIS is a term that can refer to a number of different technologies, processes. It is attached to operations and has many applications related to engineering, planning, management, transport/logistics, insurance, telecommunications. For that reason, GIS and location intelligence applications can be the foundation for many location-enabled services that rely on analysis, GIS can relate unrelated information by using location as the key index variable. Locations or extents in the Earth space–time may be recorded as dates/times of occurrence, and x, y, and z coordinates representing, longitude, latitude, all Earth-based spatial–temporal location and extent references should be relatable to one another and ultimately to a real physical location or extent. This key characteristic of GIS has begun to open new avenues of scientific inquiry, the first known use of the term geographic information system was by Roger Tomlinson in the year 1968 in his paper A Geographic Information System for Regional Planning. Tomlinson is also acknowledged as the father of GIS, previously, one of the first applications of spatial analysis in epidemiology is the 1832 Rapport sur la marche et les effets du choléra dans Paris et le département de la Seine. The French geographer Charles Picquet represented the 48 districts of the city of Paris by halftone color gradient according to the number of deaths by cholera per 1,000 inhabitants and this was one of the earliest successful uses of a geographic methodology in epidemiology. The early 20th century saw the development of photozincography, which allowed maps to be split into layers, for one layer for vegetation. This work was drawn on glass plates but later plastic film was introduced, with the advantages of being lighter, using less storage space and being less brittle. When all the layers were finished, they were combined into one using a large process camera. Once color printing came in, the idea was also used for creating separate printing plates for each color. Computer hardware development spurred by nuclear weapon research led to general-purpose computer mapping applications by the early 1960s, the year 1960 saw the development of the worlds first true operational GIS in Ottawa, Ontario, Canada by the federal Department of Forestry and Rural Development. A rating classification factor was added to permit analysis. CGIS was an improvement over computer mapping applications as it provided capabilities for overlay, measurement and it supported a national coordinate system that spanned the continent, coded lines as arcs having a true embedded topology and it stored the attribute and locational information in separate files. As a result of this, Tomlinson has become known as the father of GIS, CGIS lasted into the 1990s and built a large digital land resource database in Canada
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Weather satellite
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The weather satellite is a type of satellite that is primarily used to monitor the weather and climate of the Earth. Satellites can be polar orbiting, covering the entire Earth asynchronously, or geostationary, Meteorological satellites see more than clouds and cloud systems. City lights, fires, effects of pollution, auroras, sand and dust storms, snow cover, ice mapping, boundaries of currents, energy flows. Other types of information are collected using weather satellites. Weather satellite images helped in monitoring the volcanic ash cloud from Mount St. Helens, smoke from fires in the western United States such as Colorado and Utah have also been monitored. Other environmental satellites can detect changes in the Earths vegetation, sea state, ocean color, El Niño and its effects on weather are monitored daily from satellite images. The Antarctic ozone hole is mapped from weather satellite data, collectively, weather satellites flown by the U. S. Europe, India, China, Russia, and Japan provide nearly continuous observations for a global weather watch. As early as 1946, the idea of cameras in orbit to observe the weather was being developed and this was due to sparse data observation coverage and the expense of using cloud cameras on rockets. By 1958, the prototypes for TIROS and Vanguard were created. The first weather satellite, Vanguard 2, was launched on February 17,1959 and it was designed to measure cloud cover and resistance, but a poor axis of rotation and its elliptical orbit kept it from collecting a notable amount of useful data. The Explorer VI and VII satellites also contained weather-related experiments, the first weather satellite to be considered a success was TIROS-1, launched by NASA on April 1,1960. TIROS operated for 78 days and proved to be more successful than Vanguard 2. TIROS paved the way for the Nimbus program, whose technology and findings are the heritage of most of the Earth-observing satellites NASA, the ESSA and NOAA polar orbiting satellites followed suit from the late 1960s onward. Geostationary satellites followed, beginning with the ATS and SMS series in the late 1960s and early 1970s, observation is typically made via different channels of the electromagnetic spectrum, in particular, the visible and infrared portions. Some of these channels include Visible and Near Infrared,0.6 μm –1.6 μm – For recording cloud cover during the day Infrared,3.9 μm –7.3 μm,8.7 μm, –13. Even wind can be determined by cloud patterns, alignments and movement from successive photos, Infrared pictures depict ocean eddies or vortices and map currents such as the Gulf Stream which are valuable to the shipping industry. Fishermen and farmers are interested in knowing land and water temperatures to protect their crops against frost or increase their catch from the sea, even El Niño phenomena can be spotted. Using color-digitized techniques, the gray shaded thermal images can be converted to color for easier identification of desired information, each meteorological satellite is designed to use one of two different classes of orbit, geostationary and polar orbiting
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