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Potentially Hazardous Asteroids
A potentially hazardous object (PHO) is a near-Earth object – either an asteroid or a comet – with an orbit that can make close approaches to the Earth and which is large enough to cause significant regional damage in the Impact event, event of impact. They are conventionally defined as having a minimum orbit intersection distance with Earth of less than and an absolute magnitude of 22 or brighter, the latter of which roughly corresponds to a size larger than 140 meters. More than 99% of the known potentially hazardous objects are no impact threat over the next 100 years. , just 21 of the known potentially hazardous objects listed on the Sentry Risk Table could not be excluded as potential threats over the next hundred years. Over hundreds if not thousands of years though, the orbits of some "potentially hazardous" asteroids can evolve to live up to their namesake. Most of these objects are potentially hazardous asteroids (PHAs), and a few are comets. there are 2,304 known P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toutatis
Teutates (spelled variously Toutatis, Totatis, Totates) is a Celtic god attested in literary and epigraphic sources. His name, which is derived from a proto-Celtic word meaning "tribe", suggests he was a national god, tribal deity. The Roman poet Lucan's epic ''Pharsalia'' mentions Teutates, Esus, and Taranis as gods to whom the Gauls sacrificed humans. This rare mention of Celtic gods under their native names in a Latin text has been the subject of much comment. Almost as often commented on are Commenta Bernensia and Adnotationes Super Lucanum, the scholia to Lucan's poem (early medieval, but relying on earlier sources) which tell us the nature of these sacrifices: in particular, that victims of Teutates were immersed headfirst into a small barrel and drowned. This sacrifice has been compared with a poorly understood ritual depicted on the Gundestrup cauldron, some motifs in Irish mythology, and the death of the bog body known as the Lindow Man. Teutates appears in a number of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Business Insider
''Business Insider'' (stylized in all caps: BUSINESS INSIDER; known from 2021 to 2023 as INSIDER) is a New York City–based multinational financial and business news website founded in 2007. Since 2015, a majority stake in ''Business Insider''s parent company Insider Inc. has been owned by the international publishing house Axel Springer. It operates several international editions, including one in the United Kingdom. ''Insider'' publishes original reporting and aggregates material from other outlets. it maintained a liberal policy on the use of anonymous sources. It has also published native advertising and granted sponsors editorial control of its content. The outlet has been nominated for several awards, but has also been criticized for using factually incorrect clickbait headlines to attract viewership. In 2015, Axel Springer SE acquired 88 percent of the stake in Insider Inc. for $343 million (€306 million), implying a total valuation of $442 million. From ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
255P/Levy
255P/Levy, formerly P/2006 T1 and P/2011 Y1, is a periodic comet with an orbital period of 5.25 years. It last came to perihelion (closest approach to the Sun) on 14 January 2012. During the 2006 passage the comet achieved an apparent magnitude of ~9.5. Levy (PK06T010) was believed to have been recovered on 3 June 2011 at magnitude 19.8, but other observatories were unable to confirm a recovery. It was most likely a false positive because of large residuals. Levy was recovered on 17 December 2011 at magnitude 19.8, and given the second designation 2011 Y1. It was then numbered. It came to perihelion on 14 January 2012 at a distance of 1.007 AU from the Sun. The comet passed the Earth on 2012-Jan-26 at a distance of . During the 2012 passage the comet was originally expected to reach an apparent magnitude of 7, but the comet had been in outburst in 2006 and was much dimmer than expected when it was recovered in 2011. MPC estimates after the 2011 recovery estimated that i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
289P/Blanpain
289P/Blanpain, formerly D/1819 W1 (Blanpain) is a short-period comet with an orbital period of 5.2 years. It was discovered by Jean-Jacques Blanpain on November 28, 1819 but was considered lost until it was recovered in 2013. It was last observed in 2020. Observational history The comet was discovered by Jean-Jacques Blanpain on November 28, 1819. Blanpain described the comet as having a "very small and confused nucleus". Another independent discovery was made on December 5 of that year by J. L. Pons. Following this the comet was lost, and was given the designation 'D' (Disappeared or Dead). However, in 2003, the orbital elements of newly discovered asteroid were calculated by Marco Micheli and others to be a probable match for the lost comet. On 12 December 2003, it approached Earth at a distance of . Further observations of the asteroid in 2005 by David Jewitt using the University of Hawaii 2.2 m telescope on Mauna Kea, appeared to reveal a faint coma, which supports th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
15P/Finlay
Comet Finlay is a periodic comet with an orbital period of 6 years discovered by William Henry Finlay ( Royal Observatory, Cape of Good Hope, South Africa) on September 26, 1886. The next perihelion passage is July 13, 2021 when the comet will have a solar elongation of 54 degrees at approximately apparent magnitude 10. It last came to perihelion on December 27, 2014, at around magnitude 10. Of the numbered periodic comets, the orbit of 15P/Finlay has one of the smallest minimum orbit intersection distances with the orbit of Earth (E-MOID). In October 2060 the comet will pass about 5 million km from Earth. Description When the first orbit calculations were made in 1886, there was a similarity between this orbit and that of Francesco de Vico's lost periodic comet of 1844 ( 54P/de Vico-Swift-NEAT). Lewis Boss ( Dudley Observatory, Schenectady, United States) noted large discrepancies between the orbits and after further observations concluded that de Vico's comet could n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
55P/Tempel–Tuttle
55P/Tempel–Tuttle (commonly known as Comet Tempel–Tuttle) is a retrograde periodic comet with an orbital period of 33 years. It fits the classical definition of a Halley-type comet with a period of between 20 and 200 years. It was independently discovered by Wilhelm Tempel on 19 December 1865, and by Horace Parnell Tuttle on 6 January 1866. It is the parent body of the Leonid meteor shower. Characteristics The nucleus of the comet was observed by Hubble Space Telescope during the 1998 apparition, and assuming an albedo of 0.04, its nucleus was estimated to have a mean radius of 1.8 km. The nucleus has a reddish color, with a B−V 0.75 ± 0.05 and V−R 0.51 ± 0.05. A jet was observed emanating from the nucleus and based on its movement the rotation period was calculated to be 15.31 ± 0.03 and 14.79 ± 0.02 hours. The spectrum of the comet revealed the presence of diatomic carbon, NH2 and i The relative production rates indicate that the comet is depleted in diatomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
109P/Swift-Tuttle
1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral. In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions. In mathematics The number 1 is the first natural number after 0. Each natural numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Orbit Intersection Distance
Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of two bodies. Of greatest interest is the risk of a collision with Earth. Earth MOID is often listed on comet and asteroid databases such as the JPL Small-Body Database. MOID values are also defined with respect to other bodies as well: Jupiter MOID, Venus MOID and so on. An object is classified as a potentially hazardous object (PHO) – that is, posing a possible risk to Earth – if, among other conditions, its Earth MOID is less than 0.05 AU. For more massive bodies than Earth, there is a potentially notable close approach with a larger MOID; for instance, Jupiter MOIDs less than 1 AU are considered noteworthy since Jupiter is the most massive planet.Bruce Koehn,Minimum Orbital Intersection Distance, Lowell Observatory, retrieved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NEOWISE
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and numerous star clusters. Its observations also supported the discovery of the first Y-type brown dwarf and Earth trojan asteroid. ... . WISE performed an all-sky astronomical survey with images in 3.4, 4.6, 12 and 22 μm wavelength range bands, over ten months using a diameter infrared telescope in Earth orbit. After its solid hydrogen coolant depleted, it was placed in hibernation mode in February 2011. In 2013, NASA reactivated the WISE telescope to search for near-Earth objects (NEO), such as comets and asteroids, that could collide with Earth. The reactivation mission was called Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE). As of August 2023, NEOWISE was 40% through the 20th coverage of the full sky. Science o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ocean
The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean, Antarctic/Southern, and Arctic Ocean),"Ocean." ''Merriam-Webster.com Dictionary'', Merriam-Webster, https://www.merriam-webster.com/dictionary/ocean . Accessed March 14, 2021. and are themselves mostly divided into seas, gulfs and Lists of bodies of water#Seawater bodies, subsequent bodies of water. The ocean contains 97% of Water distribution on Earth, Earth's water and is the primary component of Earth's hydrosphere, acting as a huge Ocean heat content, reservoir of heat for Earth's energy budget, as well as for its carbon cycle and water cycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tsunami
A tsunami ( ; from , ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and underwater explosions (including detonations, landslides, glacier calvings, meteorite impacts and other disturbances) above or below water all have the potential to generate a tsunami. Unlike normal ocean waves, which are generated by wind, or tides, which are in turn generated by the gravitational pull of the Moon and the Sun, a tsunami is generated by the displacement of water from a large event. Tsunami waves do not resemble normal undersea currents or sea waves because their wavelength is far longer. Rather than appearing as a breaking wave, a tsunami may instead initially resemble a rapidly rising tide. For this reason, it is often referred to as a tidal wave, although this usage is not favoured by the scientific community because it might give the false impression of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Distance (astronomy)
The instantaneous Earth–Moon distance, or distance to the Moon, is the distance from the center of Earth to the center of the Moon. In contrast, the Lunar distance (LD or \Delta_), or Earth–Moon characteristic distance, is a unit of measure in astronomy. More technically, it is the semi-major axis of the geocentric orbit of the Moon, lunar orbit. The average lunar distance is approximately , or 1.3 light-seconds. It is roughly 30 times Earth radius, Earth's diameter and a non-stop plane flight traveling that distance would take more than two weeks. Around 389 lunar distances make up an astronomical unit (roughly the distance from Earth to the Sun). Lunar distance is commonly used to express the distance to near-Earth object encounters. Lunar semi-major axis is an important astronomical datum. It has implications for testing gravitational theories such as general relativity and for refining other astronomical values, such as the Earth mass, mass, Earth radius, radius, and Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
