1.
Left- and right-hand traffic
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This is so fundamental to traffic flow that it is sometimes referred to as the rule of the road. About two-thirds of the population use RHT, with the remaining 76 countries and territories using LHT. Countries that use LHT account for about a sixth of the worlds area, in the early 1900s some countries including Canada, Spain, and Brazil had different rules in different parts of the country. During the 1900s many countries standardised within their jurisdictions, and changed from LHT to RHT, in 1919,104 of the worlds territories were LHT and an equal number were RHT. From 1919 to 1986,34 of the LHT territories switched to RHT, many of the countries with LHT are former British colonies in the Caribbean, Southern Africa, Southeast Asia, Australia, and New Zealand. Japan, Thailand, Nepal, Bhutan, Mozambique, Suriname, East Timor, in Europe, only four countries still drive on the left, the United Kingdom, Ireland, Malta, and Cyprus, all of which are islands. Nearly all countries use one side or the other throughout their entire territory, most exceptions are due to historical considerations and involve islands with no road connection to the main part of a country. China is RHT except the Special Administrative Regions of China of Hong Kong, the United States is RHT except the United States Virgin Islands. The United Kingdom is LHT, but its overseas territories of Gibraltar, according to the International Regulations for Preventing Collisions at Sea, water traffic is RHT. For aircraft the US Federal Aviation Regulations provide for passing on the right, light rail vehicles generally operate on the same side as other road traffic in the country. Many countries use RHT for automobiles but LHT for trains, often because of the influence of the British on early railway systems, in some countries rail traffic remained LHT after automobile traffic switched to RHT, for example in China, Brazil, and Argentina. However, France, Belgium, and Switzerland have used RHT for automobiles since their introduction, there is no technical reason to prefer one side over the other. Ancient Greek, Egyptian, and Roman troops kept to the left when marching, in 1998, archaeologists found a well-preserved double track leading to a Roman quarry near Swindon. The first reference in English law to an order for LHT was in 1756, northcote Parkinson, believed that ancient travellers on horseback or on foot generally kept to the left, since most people were right handed. If two men riding on horseback were to start a fight, each would edge toward the left, in the year 1300, Pope Boniface VIII directed pilgrims to keep left. In the late 1700s, traffic in the United States was RHT based on use of large freight wagons pulled by several pairs of horses. The wagons had no seat, so a postilion sat on the left rear horse. Seated on the left, the driver preferred that other wagons pass him on the left so that he could be sure to keep clear of the wheels of oncoming wagons, in France, traditionally foot traffic had kept right, while carriage traffic kept left
2.
Lunar mare
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The lunar maria /ˈmɑːriə/ are large, dark, basaltic plains on Earths Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for seas, by astronomers who mistook them for actual seas. They are less reflective than the highlands as a result of their iron-rich compositions, the maria cover about 16 percent of the lunar surface, mostly on the side visible from Earth. The few maria on the far side are smaller, residing mostly in very large craters. The traditional nomenclature for the Moon also includes one oceanus, as well as features with the names lacus, palus, the last three are smaller than maria, but have the same nature and characteristics. The names of maria generally refer to states of mind, with a few exceptions, for example, Mare Humboldtianum and Mare Smythii were established long before the nomenclature was accepted and do not follow this pattern. The ages of the mare basalts have been determined both by direct radiometric dating and by the technique of crater counting, the few basaltic eruptions that occurred on the far side are old, whereas the youngest flows are found within Oceanus Procellarum on the nearside. While many of the basalts either erupted within, or flowed into, low-lying impact basins, there are many common misconceptions concerning the spatial distribution of mare basalts. Since many mare basalts fill low-lying impact basins, it was assumed that the impact event itself somehow caused the volcanic eruption. It is sometimes suggested that the gravity field of the Earth might preferentially allow eruptions to occur on the near side, but not far side. However, in a frame rotating with the Moon, the centrifugal acceleration the moon is experiencing is exactly equal. There is thus no net force directed towards the Earth, the Earth tides do act to deform the shape of the Moon, but this shape is one of an elongated ellipsoid with high points at both the sub- and anti-Earth points. As an analogy, one should remember that there are two high tides per day on Earth, and not one, since mare basaltic magmas are denser than upper crustal anorthositic materials, basaltic eruptions might be favored at locations of low elevation where the crust is thin. However, the far side South Pole-Aitken basin contains the lowest elevations of the Moon and is yet only modestly filled by basaltic lavas, in addition, the crustal thickness beneath this basin is predicted to be much smaller than beneath Oceanus Procellarum. It is commonly suggested that there is form of link between the synchronous rotation of the Moon about the Earth, and the mare basalts. However, gravitational torques that result in tidal despinning only arise from the moments of inertia of the body, furthermore, tidal despinning is predicted to have occurred quickly, whereas the majority of mare basalts erupted about one billion years later. The reason that the basalts are predominantly located on the near-side hemisphere of the Moon is still being debated by the scientific community. In this low-impact collision, the moon was crushed into the surface of the moon
3.
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
4.
Far side of the Moon
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The far side of the Moon is the hemisphere of the Moon that always faces away from Earth. The far sides terrain is rugged, with a multitude of impact craters and it has one of the largest craters in the Solar System, the South Pole–Aitken basin. About 18 percent of the far side is visible from Earth due to libration. The remaining 82 percent remained unobserved until 1959, when the Soviet Unions Luna 3 space probe photographed it, the Soviet Academy of Sciences published the first atlas of the far side in 1960. In 1968, the Apollo 8 missions astronauts were the first humans to view this region directly when they orbited the Moon, to date, no human being has ever stood on the surface of the far side of the Moon. Astronomers have suggested installing a large telescope on the far side. Tidal forces from Earth have slowed down the Moons rotation so that the side is always facing the Earth. The other face, most of which is never visible from the Earth, is called the far side of the Moon. Over time some parts of the far side can be due to libration. In total 59 percent of the Moons surface is visible from Earth at one time or another, useful observation of the parts of the far side of the Moon occasionally visible from Earth is difficult because of the low viewing angle from Earth. While many misconstrue this to think that the dark side receives little to no sunlight, in reality, however, the near side also receives sunlight reflected from the Earth, known as earthshine. Earthshine does not reach the area of the far side which cannot be seen from Earth, only during a full moon is the whole far side of the Moon dark. The word dark has expanded to refer to the fact that communication with spacecraft can be blocked while on the far side of the Moon. The two hemispheres have distinctly different appearances, with the near side covered in multiple, large maria, the far side has a battered, densely cratered appearance with few maria. Only 1% of the surface of the far side is covered by maria and it has also been proposed that the differences between the two hemispheres may have been caused by a collision with a smaller companion moon that also originated from the Theia collision. The far side has more visible craters and this was thought to be a result of the effects of lunar lava flows, which cover and obscure craters, rather than a shielding effect from the Earth. NASA calculates that the Earth obscures only about 4 square degrees out of 41,000 square degrees of the sky as seen from the Moon and this makes the Earth negligible as a shield for the Moon. Newer research suggests that the reason the side of the moon facing Earth has fewer impact craters is heat from Earth at the time when the Moon was formed, the lunar crust consists primarily of plagioclases formed when aluminium and calcium condensed and combined with silicates in the mantle
5.
Sun
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The Sun is the star at the center of the Solar System. It is a perfect sphere of hot plasma, with internal convective motion that generates a magnetic field via a dynamo process. It is by far the most important source of energy for life on Earth. Its diameter is about 109 times that of Earth, and its mass is about 330,000 times that of Earth, accounting for about 99. 86% of the total mass of the Solar System. About three quarters of the Suns mass consists of hydrogen, the rest is mostly helium, with smaller quantities of heavier elements, including oxygen, carbon, neon. The Sun is a G-type main-sequence star based on its spectral class and it formed approximately 4.6 billion years ago from the gravitational collapse of matter within a region of a large molecular cloud. Most of this matter gathered in the center, whereas the rest flattened into a disk that became the Solar System. The central mass became so hot and dense that it eventually initiated nuclear fusion in its core and it is thought that almost all stars form by this process. The Sun is roughly middle-aged, it has not changed dramatically for more than four billion years and it is calculated that the Sun will become sufficiently large enough to engulf the current orbits of Mercury, Venus, and probably Earth. The enormous effect of the Sun on Earth has been recognized since prehistoric times, the synodic rotation of Earth and its orbit around the Sun are the basis of the solar calendar, which is the predominant calendar in use today. The English proper name Sun developed from Old English sunne and may be related to south, all Germanic terms for the Sun stem from Proto-Germanic *sunnōn. The English weekday name Sunday stems from Old English and is ultimately a result of a Germanic interpretation of Latin dies solis, the Latin name for the Sun, Sol, is not common in general English language use, the adjectival form is the related word solar. The term sol is used by planetary astronomers to refer to the duration of a solar day on another planet. A mean Earth solar day is approximately 24 hours, whereas a mean Martian sol is 24 hours,39 minutes, and 35.244 seconds. From at least the 4th Dynasty of Ancient Egypt, the Sun was worshipped as the god Ra, portrayed as a falcon-headed divinity surmounted by the solar disk, and surrounded by a serpent. In the New Empire period, the Sun became identified with the dung beetle, in the form of the Sun disc Aten, the Sun had a brief resurgence during the Amarna Period when it again became the preeminent, if not only, divinity for the Pharaoh Akhenaton. The Sun is viewed as a goddess in Germanic paganism, Sól/Sunna, in ancient Roman culture, Sunday was the day of the Sun god. It was adopted as the Sabbath day by Christians who did not have a Jewish background, the symbol of light was a pagan device adopted by Christians, and perhaps the most important one that did not come from Jewish traditions
6.
Lunar phase
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The lunar phase or phase of the moon is the shape of the illuminated portion of the Moon as seen by an observer on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the positions of the Moon. The Moons rotation is locked by the Earths gravity, therefore the same lunar surface always faces Earth. This face is variously sunlit depending on the position of the Moon in its orbit, therefore, the portion of this hemisphere that is visible to an observer on Earth can vary from about 100% to 0%. The lunar terminator is the boundary between the illuminated and darkened hemispheres, each of the four intermediate lunar phases is roughly seven days but this varies slightly due to the elliptical shape of the Moons orbit. Aside from some craters near the lunar poles such as Shoemaker, all parts of the Moon see around 14.77 days of sunlight, in Western culture, the four principal lunar phases are new moon, first quarter, full moon, and third quarter. These are the instants when the Moons apparent geocentric celestial longitude minus the Suns apparent geocentric longitude is 0°, 90°, 180° and 270°. Each of these phases is instantaneous, lasting theoretically zero time, during the intervals between principal phases, the Moon appears either crescent-shaped or gibbous. These shapes, and the periods of time when the Moon shows them, are called the intermediate phases. They last, on average, one-quarter of a month, roughly 7.38 days, but their durations vary slightly because the Moons orbit is slightly elliptical. The descriptor waxing is used for a phase when the Moons apparent size is increasing, from new moon toward full moon. As the moon waxes, the lunar phases progress through new moon, crescent moon, first-quarter moon, gibbous moon, the moon is then said to wane as it passes through the gibbous moon, third-quarter moon, crescent moon and back to new moon. The terms old moon and new moon are not interchangeable, the old moon is a waning sliver until the moment it aligns with the sun and begins to wax, at which point it becomes new again. Half moon is used to mean the first- and third-quarter moons, while the term quarter refers to the extent of the moons cycle around the Earth. When a crescent Moon occurs, the phenomenon of earthshine may be apparent, in the Northern Hemisphere, if the left side of the Moon is dark then the light part is growing, and the Moon is referred to as waxing. If the right side of the Moon is dark then the part is shrinking. Assuming that the viewer is in the hemisphere, the right portion of the Moon is the part that is always growing. Nearer the Equator the Moon with its terminator will appear apparently horizontal during the morning and evening, the crescent Moon can open upward or downward, with the horns of the crescent pointing up or down, respectively
7.
Sunlight
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Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earths atmosphere, and is obvious as daylight when the Sun is above the horizon, when the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, the World Meteorological Organization uses the term sunshine duration to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter. Other sources indicate an Average over the earth of 164 Watts per square meter over a 24 hour day. The ultraviolet radiation in sunlight has both positive and negative effects, as it is both a principal source of vitamin D3 and a mutagen. Sunlight takes about 8.3 minutes to reach Earth from the surface of the Sun. A photon starting at the center of the Sun and changing every time it encounters a charged particle would take between 10,000 and 170,000 years to get to the surface. Researchers may record sunlight using a sunshine recorder, pyranometer, or pyrheliometer, to calculate the amount of sunlight reaching the ground, both Earths elliptical orbit and the attenuation by Earths atmosphere have to be taken into account. In this formula dn–3 is used, because in modern times Earths perihelion, the closest approach to the Sun and, therefore, the value of 0.033412 is determined knowing that the ratio between the perihelion squared and the aphelion squared should be approximately 0.935338. The solar illuminance constant, is equal to 128×103 lx, the atmospheric extinction brings the number of lux down to around 100000. The total amount of energy received at ground level from the Sun at the zenith depends on the distance to the Sun and it is about 3. 3% higher than average in January and 3. 3% lower in July. In terms of energy, sunlight at Earths surface is around 52 to 55 percent infrared,42 to 43 percent visible, and 3 to 5 percent ultraviolet. At the top of the atmosphere, sunlight is about 30% more intense, having about 8% ultraviolet, direct sunlight has a luminous efficacy of about 93 lumens per watt of radiant flux. This is higher than the efficacy of most artificial lighting, which means using sunlight for illumination heats up a less than using most forms of artificial lighting. Multiplying the figure of 1050 watts per square metre by 93 lumens per watt indicates that bright sunlight provides an illuminance of approximately 98000 lux on a surface at sea level. The illumination of a surface will be considerably less than this if the Sun is not very high in the sky. Averaged over a day, the highest amount of sunlight on a horizontal surface occurs in January at the South Pole, dividing the irradiance of 1050 W/m2 by the size of the suns disk in steradians gives an average radiance of 15.4 MW per square metre per steradian. Multiplying this by π gives a limit to the irradiance which can be focused on a surface using mirrors,48.5 MW/m2
8.
Equator
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The Equator usually refers to an imaginary line on the Earths surface equidistant from the North Pole and South Pole, dividing the Earth into the Northern Hemisphere and Southern Hemisphere. The Equator is about 40,075 kilometres long, some 78. 7% lies across water and 21. 3% over land, other planets and astronomical bodies have equators similarly defined. Generally, an equator is the intersection of the surface of a sphere with the plane that is perpendicular to the spheres axis of rotation. The latitude of the Earths equator is by definition 0° of arc, the equator is the only line of latitude which is also a great circle — that is, one whose plane passes through the center of the globe. The plane of Earths equator when projected outwards to the celestial sphere defines the celestial equator, in the cycle of Earths seasons, the plane of the equator passes through the Sun twice per year, at the March and September equinoxes. To an observer on the Earth, the Sun appears to travel North or South over the equator at these times, light rays from the center of the Sun are perpendicular to the surface of the Earth at the point of solar noon on the Equator. Locations on the Equator experience the quickest sunrises and sunsets because the sun moves nearly perpendicular to the horizon for most of the year. The Earth bulges slightly at the Equator, the diameter of the Earth is 12,750 kilometres. Because the Earth spins to the east, spacecraft must also launch to the east to take advantage of this Earth-boost of speed, seasons result from the yearly revolution of the Earth around the Sun and the tilt of the Earths axis relative to the plane of revolution. During the year the northern and southern hemispheres are inclined toward or away from the sun according to Earths position in its orbit, the hemisphere inclined toward the sun receives more sunlight and is in summer, while the other hemisphere receives less sun and is in winter. At the equinoxes, the Earths axis is not tilted toward the sun, instead it is perpendicular to the sun meaning that the day is about 12 hours long, as is the night, across the whole of the Earth. Near the Equator there is distinction between summer, winter, autumn, or spring. The temperatures are usually high year-round—with the exception of high mountains in South America, the temperature at the Equator can plummet during rainstorms. In many tropical regions people identify two seasons, the wet season and the dry season, but many places close to the Equator are on the oceans or rainy throughout the year, the seasons can vary depending on elevation and proximity to an ocean. The Equator lies mostly on the three largest oceans, the Pacific Ocean, the Atlantic Ocean, and the Indian Ocean. The highest point on the Equator is at the elevation of 4,690 metres, at 0°0′0″N 77°59′31″W and this is slightly above the snow line, and is the only place on the Equator where snow lies on the ground. At the Equator the snow line is around 1,000 metres lower than on Mount Everest, the Equator traverses the land of 11 countries, it also passes through two island nations, though without making a landfall in either. Starting at the Prime Meridian and heading eastwards, the Equator passes through, Despite its name, however, its island of Annobón is 155 km south of the Equator, and the rest of the country lies to the north
9.
Giovanni Battista Riccioli
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Giovanni Battista Riccioli was an Italian astronomer and a Catholic priest in the Jesuit order. Riccioli was born in Ferrara, Italy and he entered the Society of Jesus on 6 October 1614. After completing his novitiate, he study of the humanities in 1616, pursuing those studies first at Ferrara. From 1620 to 1628 he studied philosophy and theology at the College of Parma, Parma Jesuits had developed a strong program of experimentation, such as with falling bodies. One of the most famous Italian Jesuits of the time, Giuseppe Biancani, was teaching at Parma when Riccioli arrived there, Riccioli mentions him with gratitude and admiration. By 1628 Ricciolis studies were complete and he requested missionary work, but that request was turned down. Instead he was assigned to teach at Parma, there he taught logic, physics, and metaphysics from 1629 to 1632, and engaged in some experiments with falling bodies and pendulums. In 1632 he became a member of a group charged with the formation of younger Jesuits and he spent the 1633-1634 academic year in Mantua, where he collaborated with Niccolo Cabeo in further pendulum studies. In 1635 he was back at Parma, where he taught theology, in 1636 he was sent to Bologna to serve as Professor of theology. Riccioli described himself as a theologian, but one with a strong and ongoing interest in astronomy since his student days and he said that many Jesuits were theologians, but few were astronomers. He said that once the enthusiasm for astronomy arose within him he could never extinguish it, eventually his superiors in the Jesuit order officially assigned him to the task of astronomical research. However, he continued to write on theology. Riccioli dealt not only with astronomy in his research, but also with physics, arithmetic, geometry, optics, gnomonics, geography and he was awarded a prize by Louis XIV in recognition of his activities and their relevance to contemporary culture. Riccioli continued to publish on both astronomy and theology up to his death and he died in Bologna at 73 years of age. One of Ricciolis most significant works was his 1651 Almagestum Novum, a work consisting of over 1500 folio pages densely packed with text, tables. Riccioli envisioned that the New Almagest would have three volumes, but only the first was completed, Riccioli is credited with being the first person to precisely measure the acceleration due to gravity of falling bodies. Books 2 and 9 of the New Almagest Riccioli included a significant discussion of and extensive experimental reports on the motions of falling bodies and he was interested in the pendulum as a device for precisely measuring time. He also reported that a pendulums period increases if the amplitude of its swing is increased to 40 degrees and he sought to develop a pendulum whose period was precisely one second – such a pendulum would complete 86,400 swings in a 24-hour period
10.
Lunar Reconnaissance Orbiter
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The Lunar Reconnaissance Orbiter is a NASA robotic spacecraft currently orbiting the Moon in an eccentric polar mapping orbit. Data collected by LRO has been described as essential for planning NASAs future human and its detailed mapping program is identifying safe landing sites, locating potential resources on the Moon, characterizing the radiation environment, and demonstrating new technologies. LRO and LCROSS were launched as part of the United Statess Vision for Space Exploration program, the probe has made a 3-D map of the Moons surface at 100-meter resolution and 98. 2% coverage, including 0. 5-meter resolution images of Apollo landing sites. The first images from LRO were published on July 2,2009, the total cost of the mission is reported as US$583 million, of which $504 million pertains to the main LRO probe and $79 million to the LCROSS satellite. Developed at NASAs Goddard Space Flight Center, LRO is a large and its mission duration was planned for one year, but has since been extended numerous times after review by NASA. After completing a design review in February 2006 and a critical design review in November 2006. Launch was planned for October 2008, but this slid to April as the spacecraft underwent testing in a vacuum chamber. Launch was rescheduled for June 17,2009, because of the delay in a priority military launch, the one-day delay was to allow the Space Shuttle Endeavour a chance to lift off for mission STS-127 following a hydrogen fuel leak that canceled an earlier planned launch. In addition, LRO has provided some of the first images and precise locations of landers and equipment from previous American and Russian lunar missions, Diviner The Diviner Lunar Radiometer Experiment measures lunar surface thermal emission to provide information for future surface operations and exploration. LEND The Lunar Exploration Neutron Detector provides measurements, creates maps, LOLA The Lunar Orbiter Laser Altimeter investigation provides a precise global lunar topographic model and geodetic grid. LROC The Lunar Reconnaissance Orbiter Camera addresses the measurement requirements of landing site certification, LROC comprises a pair of narrow-angle push-broom imaging cameras and a single wide-angle camera. The mission is returning approximately 70–100 terabytes of image data and it is expected that this photography will boost public acknowledgement of the validity of the landings, and further discredit Apollo conspiracy theories. Mini-RF The Miniature Radio Frequency radar demonstrated new lightweight SAR and communications technologies, prior to the LROs launch, NASA gave members of the public the opportunity to have their names placed in a microchip on the LRO. The deadline for this opportunity was July 31,2008, about 1.6 million names were submitted. On June 23,2009, the Lunar Reconnaissance Orbiter entered into orbit around the Moon after a journey from the Earth. When launched, the spacecraft was aimed at a point ahead of the Moons position, a mid-course correction was required during the trip in order for the spacecraft to correctly enter Lunar orbit. Once the spacecraft reached the far side of the Moon, its motor was fired in order for it to be captured by the Moons gravity into an elliptical lunar orbit. A series of four rocket burns over the four days put the satellite into its commissioning phase orbit where each instrument was brought online
