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Southern Taurids
The Taurids are an annual meteor shower, associated with the comet Encke. The Taurids are actually two separate showers, with a Southern and a Northern component. The Southern Taurids originated from Comet Encke, while the Northern Taurids originated from the asteroid 2004 TG10, possibly a large fragment of Encke due to its similar orbital parameters. They are named after their radiant point in the constellation Taurus, where they are seen to come from in the sky. Because of their occurrence in late October and early November, they are also called Halloween fireballs. Since 2P/Encke is such a short period comet, the meteors have the slowest impact speed of the annual well-known meteor showers. Comet Encke and the Taurid complex are believed to be remnants of a disrupted 40-km-class comet from about 10,000 years ago, breaking into several pieces and releasing material by normal cometary activity, mass loss via YORP spin-up, or occasionally by close encounters with the tid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2P/Encke
Comet Encke , or Encke's Comet (official designation: 2P/Encke), is a periodic comet that completes an orbit of the Sun once every 3.3 years. (This is the shortest period of a reasonably bright comet; the faint main-belt comet 311P/PanSTARRS has a period of 3.2 years.) Encke was first recorded by Pierre Méchain on 17 January 1786, but it was not recognized as a periodic comet until 1819 when its orbit was computed by Johann Franz Encke. Like Halley's Comet, it is unusual in its being named after the calculator of its orbit rather than its discoverer. Like most comets, it has a very low albedo, reflecting only 4.6% of the light its comet nucleus, nucleus receives, although comets generate a large coma (cometary), coma and tail that can make them much more visible during their perihelion (closest approach to the Sun). The diameter of the nucleus of Encke's Comet is 4.8 km. Discovery As its official designation implies, Encke's Comet was the first periodic comet discovered af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dust
Dust is made of particle size, fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian processes, aeolian process), Types of volcanic eruptions, volcanic eruptions, and pollution. Dust in homes is composed of about 20–50% dead skin Cell (biology), cells. The rest, and in offices and other built environments, is composed of small amounts of plant pollen, human hairs, animal fur, textile fibers, paper fibers, minerals from outdoor soil, burnt meteorite particles, and many other materials which may be found in the local environment. Atmospheric Atmospheric or wind-borne fugitive dust, also known as ''aeolian dust'', comes from dry regions where high-speed winds can remove mostly silt-sized material, abrading susceptible surfaces. This includes areas where grazing, ploughing, vehicle use, and other human behaviors have further destabilized the land, though not all so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anno Domini
The terms (AD) and before Christ (BC) are used when designating years in the Gregorian calendar, Gregorian and Julian calendar, Julian calendars. The term is Medieval Latin and means "in the year of the Lord" but is often presented using "our Lord" instead of "the Lord", taken from the full original phrase "", which translates to "in the year of our Lord Jesus Christ". The form "BC" is specific to English language, English, and equivalent abbreviations are used in other languages: the Latin (language), Latin form, rarely used in English, is (ACN) or (AC). This calendar era takes as its epoch (date reference), epoch the traditionally reckoned year of the annunciation, conception or Nativity of Jesus, birth of Jesus. Years ''AD'' are counted forward since that epoch and years ''BC'' are counted backward from the epoch. There is no year zero in this scheme; thus the year AD 1 immediately follows the year 1 BC. This dating system was devised in 525 by Dionysius Exiguus but was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars 1
Mars 1, also known as 1962 Beta Nu 1, Mars 2MV-4 and Sputnik 23, was an automatic interplanetary station launched in the direction of Mars on November 1, 1962, the first of the Soviet Mars probe program, with the intent of flying by the planet at a distance of about . It was designed to image the surface and send back data on cosmic radiation, micrometeoroid impacts and Mars' magnetic field, radiation environment, atmospheric structure, and possible organic compounds. After leaving Earth orbit, the spacecraft and the Molniya booster's fourth stage separated and the solar panels were deployed. Early telemetry indicated that there was a leak in one of the gas valves in the orientation system so the spacecraft was transferred to gyroscopic stabilization. It made sixty-one radio transmissions, initially at two-day intervals and later at five days, containing a large amount of interplanetary data. On March 21, 1963, when the spacecraft was at a distance of from Earth on its wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geographic (magazine)
''National Geographic'' (formerly ''The National Geographic Magazine'', sometimes branded as ''Nat Geo'') is an American monthly magazine published by National Geographic Partners. The magazine was founded in 1888 as a scholarly journal, nine months after the establishment of the society, but is now a popular magazine. In 1905, it began including pictures, a style for which it became well known. Its first color photos appeared in the 1910s. During the Cold War, the magazine committed itself to present a balanced view of the physical geography, physical and human geography of countries beyond the Iron Curtain. Later, the magazine became outspoken on Environmentalism, environmental issues. Until 2015, the magazine was completely owned and managed by the National Geographic Society. Since 2015, controlling interest has been held by National Geographic Partners. Topics of features generally concern geography, history, nature, science, and world culture. The magazine is well known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunguska Event
The Tunguska event was a large explosion of between 3 and 50 TNT equivalent, megatons that occurred near the Podkamennaya Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, on the morning of 30 June 1908. The explosion over the sparsely populated East Siberian taiga felled an estimated 80 million trees over an area of of forest, and eyewitness accounts suggest up to three people may have died. The explosion is attributed to a meteor air burst, the atmospheric explosion of a stony asteroid about wide. The asteroid approached from the east-south-east, probably with a relatively high speed of about . Though the incident is classified as an impact event, the object is thought to have exploded at an altitude of rather than hitting the Earth's surface, leaving no impact crater. The Tunguska event is the largest impact event on Earth in recorded history, though List of impact craters on Earth, much larger impacts are believed to have occurred in prehistoric ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bill Napier
William M. Napier (born 29 June 1940) is a Scottish author. Napier is best known for authoring five high tech thriller novels and a number of nonfiction science books that concern fringe and pseudoscientific theories. Career He received his Bachelor of Science degree in 1963 and his Doctor of Philosophy degree in 1966, both from the University of Glasgow. Napier is a professional astronomer who has worked at the Royal Observatory in Edinburgh, the University of Oxford and Armagh Observatory. He is currently an honorary professor of Astrobiology in the Center for Astrobiology at Cardiff University, which describes him as "a leading figure in the dynamics and physics of comets, and a pioneer of the modern versions of catastrophism." And honorary professor at the Buckingham Centre for Astrobiology, University of Buckingham, which describes him as, "a pioneer of modern studies of the impact hazard due to asteroids and comets," and also as having, "carried out an investigation o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duncan Steel
Duncan I. Steel (born 1955) is a British space scientist. He has discovered several minor planets and has written four popular science books. He is a member of the International Astronomical Union, and has worked at the Xerra Earth Observation Institute in Nelson, in the South Island of New Zealand. He was formerly on the staff of the University of Salford in the United Kingdom. Steel completed a PhD at the University of Canterbury in 1984 with a thesis on the orbital characteristics of meteoroids. Between 1990 and 1994 he discovered twelve numbered minor planets. The asteroid 4713 Steel, discovered by Robert McNaught in 1989, is named after him. In August 2022 Steel pleaded guilty to burglary and breaching the New Zealand Harmful Digital Communications Act. He was sentenced to 12 months' house arrest and ordered to pay $3000 in reparation for emotional harm. Books * (with a foreword by Arthur C. Clarke). * (with an afterword by Arthur C. Clarke). * * (with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter
Jupiter is the fifth planet from the Sun and the List of Solar System objects by size, largest in the Solar System. It is a gas giant with a Jupiter mass, mass more than 2.5 times that of all the other planets in the Solar System combined and slightly less than one-thousandth the mass of the Sun. Its diameter is 11 times that of Earth and a tenth that of the Sun. Jupiter orbits the Sun at a distance of , with an orbital period of . It is the List of brightest natural objects in the sky, third-brightest natural object in the Earth's night sky, after the Moon and Venus, and has been observed since prehistoric times. Its name derives from that of Jupiter (god), Jupiter, the chief deity of ancient Roman religion. Jupiter was the first of the Sun's planets to form, and its inward migration during the primordial phase of the Solar System affected much of the formation history of the other planets. Jupiter's atmosphere consists of 76% hydrogen and 24% helium by mass, with a denser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planet
A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets by the most restrictive definition of the term: the terrestrial planets Mercury (planet), Mercury, Venus, Earth, and Mars, and the giant planets Jupiter, Saturn, Uranus, and Neptune. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a young protostar orbited by a protoplanetary disk. Planets grow in this disk by the gradual accumulation of material driven by gravity, a process called accretion (astrophysics), accretion. The word ''planet'' comes from the Greek () . In Classical antiquity, antiquity, this word referred to the Sun, Moon, and five points of light visible to the naked eye that moved across the background of the stars—namely, Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation (astronomy)
In astronomy, perturbation is the complex motion of a massive body subjected to forces other than the gravitational attraction of a single other massive body. The other forces can include a third (fourth, fifth, etc.) body, resistance, as from an atmosphere, and the off-center attraction of an oblate or otherwise misshapen body. Introduction The study of perturbations began with the first attempts to predict planetary motions in the sky. In ancient times the causes were unknown. Isaac Newton, at the time he formulated his laws of motion and of gravitation, applied them to the first analysis of perturbations, recognizing the complex difficulties of their calculation. Many of the great mathematicians since then have given attention to the various problems involved; throughout the 18th and 19th centuries there was demand for accurate tables of the position of the Moon and planets for marine navigation. The complex motions of gravitational perturbations can be broken down. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolide
A bolide is normally taken to mean an exceptionally bright meteor, but the term is subject to more than one definition, according to context. It may refer to any large Impact crater, crater-forming body, or to one that explodes in the atmosphere. It can be a synonym for a Meteoroid#Fireball, fireball, sometimes specific to those with an apparent magnitude of −4 or brighter. Definitions The word ''bolide'' (; from Italian language, Italian via Latin, ) may refer to somewhat different phenomena depending on the context in which the word appears, and readers may need to make inferences to determine which meaning is intended in a particular publication. An early usage occurs in ''Natural History (Pliny), Natural History'', where Pliny the Elder describes two types of prodigium, prodigies, "those which are called lampades and those which are called bolides". At least one of the prodigies described by Pliny (a "spark" that fell, grew to the "size of the moon", and "returned into the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
