Space probe
A space probe is a robotic spacecraft that does not orbit Earth, but instead, explores further into outer space. A space probe may approach the Moon; the space agencies of the USSR, the United States, the European Union, China,India, Israel have collectively launched probes to several planets and moons of the Solar System, as well as to a number of asteroids and comets. 15 missions are operational. Once a probe has left the vicinity of Earth, its trajectory will take it along an orbit around the Sun similar to the Earth's orbit. To reach another planet, the simplest practical method is a Hohmann transfer orbit. More complex techniques, such as gravitational slingshots, can be more fuel-efficient, though they may require the probe to spend more time in transit; some high Delta-V missions can only be performed, within the limits of modern propulsion, using gravitational slingshots. A technique using little propulsion, but requiring a considerable amount of time, is to follow a trajectory on the Interplanetary Transport Network.
First man-made object to any other extra terrestrial surface. First mission to photograph the far side of the Moon, launched in 1959. First robotic sample return probe from the Moon. First rover on Moon, it was sent to the Moon on November 10, 1970. First probe to Mercury. First successful in-place analysis of another planet, it may have been the first space probe to impact the surface of another planet, although it is unclear whether it reached Venus' surface. The Venera 7 probe was the first spacecraft to soft land on another planet and to transmit data from there back to Earth. Upon its arrival at Mars on November 13, 1971, Mariner 9 became the first space probe to maintain orbit around another planet. First soft landing on Mars The lander began transmitting to the Mars 3 orbiter 90 seconds after landing. After 20 seconds, transmission stopped for unknown reasons. First successful rover on Mars; the Mars Exploration Rovers and Opportunity landed on Mars to explore the Martian surface and geology, searched for clues to past water activity on Mars.
They were each launched in 2003 and landed in 2004. Communication with Spirit stopped on sol 2210. JPL continued to attempt to regain contact until May 24, 2011, when NASA announced that efforts to communicate with the unresponsive rover had ended. Opportunity arrived at Endeavour crater on 9 August 2011, at a landmark called Spirit Point named after its rover twin, after traversing 13 miles from Victoria crater, over a three-year period. After a planet wide dust storm in June 2018, the final communication was received on June 10, 2018, Opportunity was declared dead on February 13, 2019; the rover lasted for fifteen years on Mars — although the rover was intended to last only three months. The first dedicated missions to a comet, it was the first massive international coordination of space probes on an interplanetary mission, with probes launched by the Soviet Space Agency, European Space Agency, Japan's ISAS. A solar observatory in the International Sun-Earth Explorer series, it was sent into solar orbit to make the first close observations of a comet, Comet Giacobini–Zinner, in 1985 as a prelude to studies of Halley's Comet.
Two Russian/French spacecraft. They dropped balloons at Venus before their rendezvous with Halley's Comet; this Japanese probe was the first non-Soviet interplanetary probe. A second Japanese probe, it made ultraviolet wavelength observations of the comet; the first space probe to take close-up images of its nucleus. First solar wind sample return probe from sun-earth L1. First sample return probe from a comet tail. First probe to land on an asteroid. First sample return probe to launch from an asteroid; the Rosetta space probe flew by two asteroids and made a rendezvous and orbited comet 67P/Churyumov-Gerasimenko in November 2014. First probe to Jupiter. Radio communications were lost with Pioneer 10 on January 23, 2003, because of the loss of electric power for its radio transmitter, with the probe at a distance of 12 billion kilometers from Earth. First probe to fly by Saturn. Voyager 1 is a 733-kilogram probe launched September 5, 1977, it visited Jupiter and Saturn and was the first probe to provide detailed images of the moons of these planets.
Voyager 1 is the farthest human-made object from Earth, traveling away from both the Earth and the Sun at a faster speed than any other probe. As of September 12, 2013, Voyager 1 is about 12 billion miles from the Sun. On August 25, 2012, Voyager 1 became. Voyager 1 has not had a functioning plasma sensor since 1980, but a solar flare in 2012 allowed scientists from NASA to measure vibrations of the plasma surrounding the craft; the vibrations allowed scientists to measure the plasma to be much denser than measurements taken in the far layers of our heliosphere, thus concluding the craft had broken beyond the heliopause. Voyager 2 was launched by NASA on August 20, 1977; the probe's primary mission was to visit the ice giants and Neptune, which it completed on October 2, 1989. It is the only probe to have visited the ice giants, it is the four
Shield
A shield is a piece of personal armour held in the hand or mounted on the wrist or forearm. Shields are used to intercept specific attacks, whether from close-ranged weaponry or projectiles such as arrows, by means of active blocks, as well as to provide passive protection by closing one or more lines of engagement during combat. Shields vary in size and shape, ranging from large panels that protect the user's whole body to small models that were intended for hand-to-hand-combat use. Shields vary a great deal in thickness. Shields vary in shape, ranging in roundness to angularity, proportional length and width and edge pattern. In prehistory and during the era of the earliest civilisations, shields were made of wood, animal hide, woven reeds or wicker. In classical antiquity, the Barbarian Invasions and the Middle Ages, they were constructed of poplar tree, lime or another split-resistant timber, covered in some instances with a material such as leather or rawhide and reinforced with a metal boss, rim or banding.
They were carried by foot soldiers and cavalry. Depending on time and place, shields could be round, square, triangular, bilabial or scalloped. Sometimes they took on the form of kites or flatirons, or had rounded tops on a rectangular base with an eye-hole, to look through when used with combat; the shield was held by straps that went over or around the user's arm. Shields were decorated with a painted pattern or an animal representation to show their army or clan; these designs developed into systematized heraldic devices during the High Middle Ages for purposes of battlefield identification. After the introduction of gunpowder and firearms to the battlefield, shields continued to be used by certain groups. In the 18th century, for example, Scottish Highland fighters liked to wield small shields known as targes, as late as the 19th century, some non-industrialized peoples employed them when waging war. In the 20th and 21st century, shields have been used by military and police units that specialize in anti-terrorist actions, hostage rescue, riot control and siege-breaking.
The modern term refers to a device, held in the hand or attached to the arm, as opposed to an armored suit or a bullet-proof vest. Shields are sometimes mounted on vehicle-mounted weapons to protect the operator; the oldest form of shield was a protection device designed to block attacks by hand weapons, such as swords and maces, or ranged weapons like sling-stones and arrows. Shields have varied in construction over time and place. Sometimes shields were made of metal. Many surviving examples of metal shields are felt to be ceremonial rather than practical, for example the Yetholm-type shields of the Bronze Age, or the Iron Age Battersea shield. Size and weight varied greatly. Armored warriors relying on speed and surprise would carry light shields that were either small or thin. Heavy troops might be equipped with robust shields. Many had a strap called a guige that allowed them to be slung over the user's back when not in use or on horseback. During the 14th–13th century BC, the Sards or Shardana, working as mercenaries for the Egyptian pharaoh Ramses II, utilized either large or small round shields against the Hittites.
The Mycenaean Greeks used two types of shields: the "figure-of-eight" shield and a rectangular "tower" shield. These shields were made from a wicker frame and reinforced with leather. Covering the body from head to foot, the figure-of-eight and tower shield offered most of the warrior's body a good deal of protection in head-to-head combat; the Ancient Greek hoplites used a round, bowl-shaped wooden shield, reinforced with bronze and called an aspis. Another name for this type of shield is a hoplon; the hoplon shield inspired the name for hoplite soldiers. The hoplon was the longest-lasting and most famous and influential of all of the ancient Greek shields; the Spartans used the aspis to create the Greek phalanx formation. Their shields offered protection not only for their comrades to their left. Examples of Germanic wooden shields circa 350 BC – 500 AD survive from weapons sacrifices in Danish bogs; the armored Roman legionaries carried large shields that could provide far more protection, but made swift movement a little more difficult.
The scutum had an oval shape, but the curved tops and sides were cut to produce the familiar rectangular shape most seen in the early Imperial legions. Famously, the Romans used their shields to create a tortoise-like formation called a testudo in which entire groups of soldiers would be enclosed in an armoured box to provide protection against missiles. Many ancient shield designs featured incuts of another; this was done to accommodate the shaft of a spear, thus facilitating tactics requiring the soldiers to stand close together forming a wall of shields. Typical in the early European Middle Ages were round shields with light, non-splitting wood like linden, alder or poplar reinforced with leather cover on one or both sides and metal rims, encircling a metal s
Planetary nebula
A planetary nebula, abbreviated as PN or plural PNe, is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is arguably a misnomer because they are unrelated to planets or exoplanets; the true origin of the term was derived from the planet-like round shape of these nebulae as observed by astronomers through early telescopes, although the terminology is inaccurate, it is still used by astronomers today. The first usage may have occurred during the 1780s with the English astronomer William Herschel who described these nebulae as resembling planets, they are a short-lived phenomenon, lasting a few tens of thousands of years, compared to longer phases of stellar evolution. Once all of the red giant's atmosphere has been dissipated, energetic ultraviolet radiation from the exposed hot luminous core, called a planetary nebula nucleus, ionizes the ejected material. Absorbed ultraviolet light energises the shell of nebulous gas around the central star, causing it to appear as a brightly coloured planetary nebula.
Planetary nebulae play a crucial role in the chemical evolution of the Milky Way by expelling elements into the interstellar medium from stars where those elements were created. Planetary nebulae are observed in more distant galaxies, yielding useful information about their chemical abundances. Starting from the 1990s, Hubble Space Telescope images revealed that many planetary nebulae have complex and varied morphologies. About one-fifth are spherical, but the majority are not spherically symmetric; the mechanisms that produce such a wide variety of shapes and features are not yet well understood, but binary central stars, stellar winds and magnetic fields may play a role. The first planetary nebula discovered was the Dumbbell Nebula in the constellation of Vulpecula, it was listed as M27 in his catalogue of nebulous objects. To early observers with low-resolution telescopes, M27 and subsequently discovered planetary nebulae resembled the giant planets like Uranus. William Herschel, discoverer of Uranus coined the term "planetary nebula".
However, in as early as January 1779, the French astronomer Antoine Darquier de Pellepoix described in his observations of the Ring Nebula, "a dull nebula, but outlined. Whatever the true origin of the term, the label "planetary nebula" became ingrained in the terminology used by astronomers to categorize these types of nebulae, is still in use by astronomers today; the true nature of these objects was uncertain, Herschel first thought the objects were stars surrounded by material, condensing into planets rather than what is now known to be evidence of dead stars that have incinerated any orbiting planets. In 1782, William Herschel had discovered the object now known as NGC 7009, upon which he used the term "planetary nebula". In 1785, Herschel wrote to Jerome Lalande: "These are celestial bodies of which as yet we have no clear idea and which are of a type quite different from those that we are familiar with in the heavens. I have found four that have a visible diameter of between 15 and 30 seconds.
These bodies appear to have a disk, rather like a planet, to say, of equal brightness all over, round or somewhat oval, about as well defined in outline as the disk of the planets, of a light strong enough to be visible with an ordinary telescope of only one foot, yet they have only the appearance of a star of about ninth magnitude." Herschel assigned these to Class IV of his catalogue of "nebulae" listing 78 "planetary nebulae", most of which are in fact galaxies. The nature of planetary nebulae remained unknown until the first spectroscopic observations were made in the mid-19th century. Using a prism to disperse their light, William Huggins was one of the earliest astronomers to study the optical spectra of astronomical objects. On August 29, 1864, Huggins was the first to analyze the spectrum of a planetary nebula when he observed Cat's Eye Nebula, his observations of stars had shown that their spectra consisted of a continuum of radiation with many dark lines superimposed. He found that many nebulous objects such as the Andromeda Nebula had spectra that were quite similar.
However, when Huggins looked at the Cat's Eye Nebula, he found a different spectrum. Rather than a strong continuum with absorption lines superimposed, the Cat's Eye Nebula and other similar objects showed a number of emission lines. Brightest of these was at a wavelength of 500.7 nanometres, which did not correspond with a line of any known element. At first, it was hypothesized that the line might be due to an unknown element, named nebulium. A similar idea had led to the discovery of helium through analysis of the Sun's spectrum in 1868. While helium was isolated on Earth soon after its discovery in the spectrum of the Sun, "nebulium" was not. In the early 20th century, Henry Norris Russell proposed that, rather than being a new element, the line at 500.7 nm was due to a familiar element in unfamiliar conditions. Physicists showed in the 1920s that in gas at low densities, electrons can occupy excited metastable energy levels in atoms and ions that would otherwise be de-excited by collisions that would occur
Marcin Odlanicki Poczobutt
Marcin Odlanicki Poczobutt was a Polish–Lithuanian jesuit and mathematician. He was professor of Vilnius University for over 50 years, serving as its rector from 1780 to 1799; the Poczobutt crater on the Moon is named after him. Marcin Odlanicki Poczobutt was born in the village of Słomianka near Grodno, he studied at Charles University in Prague. With brief interruptions he lectured at Vilnius University from 1753 to 1808. Sponsored by Michał Fryderyk Czartoryski, he further studied in France and Germany from 1762 to 1764, his stay at the Marseille Observatory under Esprit Pézenas inspired him to devote his career to astronomy. He earned doctorate of philosophy, gained professorship, became director of the Vilnius Astronomical Observatory in 1764; the observatory, established by Thomas Zebrowski, was in its early stages of development and Poczobutt worked hard to obtain modern instruments. Despite suppression of the Jesuits in 1773, the observatory gained royal favour from King Stanisław August Poniatowski—it was named royal observatory and Poczobutt became King's astronomer.
In 1780, Poczobutt was appointed as university rector by the Commission of National Education. He was tasked with reforming the university from a medieval school concentrated on humanities to a modern scientific institution. Under Poczobutt the university improved its science and law departments; as rector of the university he promoted the use of Latin and opposed any use of Polish or Lithuanian languages. He travelled to London where he ordered astronomical equipment from Jesse Ramsden and John Dollond: a 4-foot transit telescope in 1765, 3.5-foot achromatic telescope in 1770, 8-foot mural quadrant in 1777, meridian circle in 1788. Other purchases included octant, two theodolites, 10-foot sextant; the observatory was expanded by architect Marcin Knackfus in 1782–1788 to accommodate the new equipment. Poczobutt observed solar and lunar eclipses and asteroids, calculated geographic coordinates of settlements in the Grand Duchy of Lithuania. In addition, he made measurements of Mercury to compute its orbit.
He described 16-star constellation. His recorded observations amounted to 34 volumes. In 1770 he became the first in Lithuania to systematically record weather temperature. Poczobutt was elected a fellow of the Royal Society in 1771 and a corresponding member of the French Academy of Sciences in 1778, he was made a member of the Order of Saint Stanislaus in 1785 and Order of the White Eagle in 1793. List of Roman Catholic scientist-clerics
IC 1295
IC 1295 is a planetary nebula in the constellation Scutum, lying 3300 light-years away. List of planetary nebulae Index Catalogue IC 1295 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Sky Map and images
Exoplanet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first evidence of an exoplanet was not recognized as such; the first scientific detection of an exoplanet was in 1988. The first confirmed detection occurred in 1992; as of 1 April 2019, there are 4,023 confirmed planets in 3,005 systems, with 656 systems having more than one planet. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like stars have an "Earth-sized" planet in the habitable zone. Assuming there are 200 billion stars in the Milky Way, it can be hypothesized that there are 11 billion habitable Earth-sized planets in the Milky Way, rising to 40 billion if planets orbiting the numerous red dwarfs are included; the least massive planet known is Draugr, about twice the mass of the Moon.
The most massive planet listed on the NASA Exoplanet Archive is HR 2562 b, about 30 times the mass of Jupiter, although according to some definitions of a planet, it is too massive to be a planet and may be a brown dwarf instead. There are planets that are so near to their star that they take only a few hours to orbit and there are others so far away that they take thousands of years to orbit; some are so far out. All of the planets detected so far are within the Milky Way. Nonetheless, evidence suggests that extragalactic planets, exoplanets farther away in galaxies beyond the local Milky Way galaxy, may exist; the nearest exoplanet is Proxima Centauri b, located 4.2 light-years from Earth and orbiting Proxima Centauri, the closest star to the Sun. The discovery of exoplanets has intensified interest in the search for extraterrestrial life. There is special interest in planets that orbit in a star's habitable zone, where it is possible for liquid water, a prerequisite for life on Earth, to exist on the surface.
The study of planetary habitability considers a wide range of other factors in determining the suitability of a planet for hosting life. Besides exoplanets, there are rogue planets, which do not orbit any star; these tend to be considered as a separate category if they are gas giants, in which case they are counted as sub-brown dwarfs, like WISE 0855−0714. The rogue planets in the Milky Way number in the billions; the convention for designating exoplanets is an extension of the system used for designating multiple-star systems as adopted by the International Astronomical Union. For exoplanets orbiting a single star, the designation is formed by taking the name or, more designation of its parent star and adding a lower case letter; the first planet discovered in a system is given the designation "b" and planets are given subsequent letters. If several planets in the same system are discovered at the same time, the closest one to the star gets the next letter, followed by the other planets in order of orbital size.
A provisional IAU-sanctioned standard exists to accommodate the designation of circumbinary planets. A limited number of exoplanets have IAU-sanctioned proper names. Other naming systems exist. For centuries scientists and science fiction writers suspected that extrasolar planets existed, but there was no way of detecting them or of knowing their frequency or how similar they might be to the planets of the Solar System. Various detection claims made in the nineteenth century were rejected by astronomers; the first evidence of an exoplanet was not recognized as such. The first suspected scientific detection of an exoplanet occurred in 1988. Shortly afterwards, the first confirmed detection came in 1992, with the discovery of several terrestrial-mass planets orbiting the pulsar PSR B1257+12; the first confirmation of an exoplanet orbiting a main-sequence star was made in 1995, when a giant planet was found in a four-day orbit around the nearby star 51 Pegasi. Some exoplanets have been imaged directly by telescopes, but the vast majority have been detected through indirect methods, such as the transit method and the radial-velocity method.
In February 2018, researchers using the Chandra X-ray Observatory, combined with a planet detection technique called microlensing, found evidence of planets in a distant galaxy, stating "Some of these exoplanets are as small as the moon, while others are as massive as Jupiter. Unlike Earth, most of the exoplanets are not bound to stars, so they're wandering through space or loosely orbiting between stars. We can estimate. In the sixteenth century the Italian philosopher Giordano Bruno, an early supporter of the Copernican theory that Earth and other planets orbit the Sun, put forward the view that the fixed stars are similar to the Sun and are accompanied by planets. In the eighteenth century the same possibility was mentioned by Isaac Newton in the "General Scholium" that concludes his Principia. Making a comparison to the Sun's planets, he wrote "And if the fixed stars are the centres of similar systems, they will all be constructed according to a similar design and subject to the dominion of One."In 1952, more than 40 years before the first hot Jupiter was discovere
Aquila (constellation)
Aquila is a constellation on the celestial equator. Its name is Latin for'eagle' and it represents the bird that carried Zeus/Jupiter's thunderbolts in Greco-Roman mythology, its brightest star, Altair, is one vertex of the Summer Triangle asterism. The constellation is best seen in the northern summer; because of this location, many clusters and nebulae are found within its borders, but they are dim and galaxies are few. Aquila was one of the 48 constellations described by the second-century astronomer Ptolemy, it had been earlier mentioned by Eudoxus in the fourth century BC and Aratus in the third century BC. It is now one of the 88 constellations defined by the International Astronomical Union; the constellation was known as Vultur volans to the Romans, not to be confused with Vultur cadens, their name for Lyra. It is held to represent the eagle which held Zeus's/Jupiter's thunderbolts in Greco-Roman mythology. Aquila is associated with the eagle that kidnapped Ganymede, a son of one of the kings of Troy, to Mount Olympus to serve as cup-bearer to the gods.
Ptolemy catalogued 19 stars jointly in this constellation and in the now obsolete constellation of Antinous, named in the reign of the emperor Hadrian, but sometimes erroneously attributed to Tycho Brahe, who catalogued 12 stars in Aquila and seven in Antinous. Hevelius determined 23 stars in 19 in the second; the Greek Aquila is based on the Babylonian constellation of the Eagle, located in the same area as the Greek constellation. Aquila, which lies in the Milky Way, contains many rich starfields and has been the location of many novae. Α Aql is the brightest star in this constellation and one of the closest naked-eye stars to Earth at a distance of 17 light-years. Its name comes from the Arabic phrase al-nasr al-tair, meaning "the flying eagle". Altair has a magnitude of 0.76. Β Aql is a yellow-hued star of 45 light-years from Earth. Its name comes from the Arabic phrase shahin-i tarazu, meaning "the balance". Γ Aql is an orange-hued giant star of 460 light-years from Earth. Its name, like that of Alshain, comes from the Arabic for "the balance".
Ζ Aql is a blue-white-hued star of 83 light-years from Earth. Η Aql is 1200 light-years from Earth. Among the brightest Cepheid variable stars, it has a minimum magnitude of 4.4 and a maximum magnitude of 3.5 with a period of 7.2 days. 15 Aql is an optical double star. The primary is an orange-hued giant of 325 light-years from Earth; the secondary is a purple-hued star of 550 light-years from Earth. The pair is resolved in small amateur telescopes. 57 Aql is a binary star. The primary is a blue-hued star of magnitude 5.7 and the secondary is a white star of magnitude 6.5. The system is 350 light-years from Earth. R Aql is a red-hued giant star 690 light-years from Earth, it is a Mira variable with a minimum magnitude of 12.0, a maximum magnitude of 6.0, a period around 9 months. It has a diameter of 400 D☉. FF Aql is a yellow-white-hued supergiant star, 2500 light-years from Earth, it is a Cepheid variable star with a minimum magnitude of 5.7, a maximum magnitude of 5.2, a period of 4.5 days. Ρ Aql moved across the border into neighboring Delphinus in 1992.
Two major novae have been observed in Aquila. Three interesting planetary nebulae lie in Aquila: NGC 6804 shows a small but bright ring. NGC 6781 bears some resemblance with the Owl Nebula in Ursa Major. NGC 6751 known as the Glowing Eye, is a planetary nebula. More deep-sky objects: NGC 6709 is a loose open cluster containing 40 stars, which range in magnitude from 9 to 11, it is about 3000 light-years from Earth. It is about 9100 light-years from Earth. NGC 6709 appears in a rich Milky Way star field and is classified as a Shapley class d and Trumpler class III 2 m cluster; these designations mean that it does not have many stars, is loose, does not show greater concentration at the center, has a moderate range of star magnitudes. NGC 6755 is an open cluster of 7.5 m. NGC 6760 is a globular cluster of 9.1 m. NGC 6749 is an open cluster. NGC 6778 is a planetary nebula. NGC 6741 is a planetary nebula. NGC 6772 is a planetary nebula. Aquila holds some extragalactic objects. One of them is what may be the largest single mass concentration of galaxies in the Universe known, the Hercules–Corona Borealis Great Wall.
It was discovered in November 2013, has the size of 10 billion light years. It is the most massive structure in the Universe known. NASA's Pioneer 11 space probe, which flew by Jupiter and Saturn in the 1970s, is expected to pass near the star Lambda Aquilae in about 4 million years. In illustrations of Aquila that represent it as an eagle, a nearly straight line of three stars symbolizes part of the wings; the center and brightest of these three stars is Altair. The tips of the wings extend further to the southeast and northwest; the head of the eagle stretches off to the southwest. According to Gavin White, the Babylonian Eagle carried the constellation called the Dead Man in its talons; the author draws a comparison to the classical stories of Antinous and Ganymede. In classical Greek mythology, Aquila was identified as Αετός Δίας, the eagle that
