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5261 Eureka
5261 Eureka is the first Mars trojan discovered. It was discovered by David H. Levy and Henry Holt at Palomar Observatory on 20 June 1990. It trails Mars (at the ) at a distance varying by only 0.3 AU during each revolution (with a secular trend superimposed, changing the distance from 1.5–1.8 AU around 1850 to 1.3–1.6 AU around 2400). Minimum distances from Earth, Venus, and Jupiter, are 0.5, 0.8, and 3.5 AU, respectively. Long-term numerical integration shows that the orbit is stable. Kimmo A. Innanen and Seppo Mikkola note that "contrary to intuition, there is clear empirical evidence for the stability of motion around the and points of all the terrestrial planets over a timeframe of several million years". Since the discovery of 5261 Eureka, the Minor Planet Center has recognized three other asteroids as Martian trojans: at the point, at the point, and , also at the point. At least five other asteroids in near-1:1 resonances with Mars have been discovered, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
David H
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". was, according to the Hebrew Bible, the Kings of Israel and Judah, third king of the Kingdom of Israel (united monarchy), United Kingdom of Israel. In the Books of Samuel, he is described as a young shepherd and Lyre, harpist who gains fame by slaying Goliath, a champion of the Philistines, in southern Canaan. David becomes a favourite of Saul, the first king of Israel; he also forges David and Jonathan, a notably close friendship with Jonathan (1 Samuel), Jonathan, a son of Saul. However, under the paranoia that David is seeking to usurp the throne, Saul attempts to kill David, forcing the latter to go into hiding and effectively operate as a fugitive for several years. After Saul and Jonathan are both killed in battle against the Philistin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimmo Innanen
Kimmo Albin Innanen (March 12, 1937 – August 3, 2011) was a Canadian astrophysicist of Finnish descent. Early life and education Kim grew up in Toronto. His first language was Finnish. He obtained a bachelor's degree in engineering physics with honors from the University of Toronto. In 1960, he received his master's degree in applied mathematics at the University of Waterloo. He completed his doctorate at the University of Toronto in 1964. Career In 1966, he joined the Department of Physics (later Physics and Astronomy) at York University. His research in celestial mechanics, galactic dynamics, and later in Solar System applications and asteroids, led to the publication of more than 100 papers. In 1990, with Seppo Mikkola, he predicted the existence of Mars Trojans, confirmed by subsequent discovery and, in 1997, he was involved in the discovery of the Earth's first co-orbital companion asteroid, 3753 Cruithne. He served as the dean of science from 1986 to 1994. He re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar System
The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar System" and "solar system" structures in theinaming guidelines document. The name is commonly rendered in lower case ('solar system'), as, for example, in the ''Oxford English Dictionary'' an''Merriam-Webster's 11th Collegiate Dictionary''. is the gravity, gravitationally bound system of the Sun and the objects that orbit it. It Formation and evolution of the Solar System, formed 4.6 billion years ago from the gravitational collapse of a giant interstellar molecular cloud. The solar mass, vast majority (99.86%) of the system's mass is in the Sun, with most of the Jupiter mass, remaining mass contained in the planet Jupiter. The four inner Solar System, inner system planets—Mercury (planet), Mercury, Venus, Earth and Mars—are terrest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation. Surface albedo is defined as the ratio of Radiosity (radiometry), radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angrite
Angrites are a rare group of achondrites consisting mostly of Al-Ti bearing diopside, hedenbergite, olivine, anorthite and troilite with minor traces of phosphate and metals. The group is named for the Angra dos Reis meteorite. They are the oldest igneous rocks, with crystallization ages of around 4.56 billion years. Angrites are subdivided into two main groups, the quenched and plutonic angrites. The quenched angrites cooled rapidly upon the surface of the angrite parent body (APB), whereas the plutonic angrites cooled slower, deeper in the crust. The APB is thought to have been a similar size to the asteroid 4 Vesta. Origin Angrite meteorites are distinct from other meteoritic groups based on their oxygen isotopic compositions. Based on their Mn-Fe ratios in pyroxene and other isotopic compositions, the source of angrites is constrained to the inner Solar System. However, recent studies have suggested that the APB experienced mixing of multiple sources during its history. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achondrite
An achondrite is a stony meteorite that does not contain chondrules. It consists of material similar to terrestrial basalts or plutonic rocks and has been differentiated and reprocessed to a lesser or greater degree due to melting and recrystallization on or within meteorite parent bodies. As a result, achondrites have distinct textures and mineralogies indicative of igneous processes. Achondrites account for about 8% of meteorites overall, and the majority (about two-thirds) of them are HED meteorites, possibly originating from the crust of asteroid 4 Vesta. Other types include Martian, Lunar, and several types thought to originate from as-yet unidentified asteroids. These groups have been determined on the basis of e.g. the Fe/ Mn chemical ratio and the 17O/18O oxygen isotope ratios, thought to be characteristic "fingerprints" for each parent body. Classification Achondrites are classified into the following groups:O. Richard Norton. The Cambridge encyclopedia of meteorites. U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A-type Asteroid
A-type asteroids are relatively uncommon inner-belt asteroids that have a strong, broad 1 micrometre, μm olivine feature and a very reddish spectrum shortwards of 0.7 μm. They are thought to come from the completely differentiated Mantle (geology), mantle of an asteroid, and appear to have a high density. One survey found that 7 similar A-, V- and X-type asteroids had an average density of .P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. ''Astronomy & Astrophysics'' 54, A56 List A-type asteroids are so rare that as of February 2019, only 17 had been discovered: See also *Asteroid spectral types References External links Mineralogic and Temperature-Induced Spectral Investigations of A-type Asteroids: (246) Asporina and (446) Aeternitas Vishnu Vardhan Reddy, V. Reddy, Lunar and Planetary Science XXXVI (2005) Asteroid spectral classes A-type asteroids, {{beltasteroid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YORP Effect video game series
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Yorp or YORP may refer to one of the following: * 54509 YORP, an Earth co-orbital asteroid *Yarkovsky–O'Keefe–Radzievskii–Paddack effect, a second-order variation on the Yarkovsky effect *Yorps, friendly one-eyed Martians from the Commander Keen ''Commander Keen'' is a series of side-scrolling platform video games developed primarily by id Software. The series consists of six main episodes, a "lost" episode, and a final game; all but the final game were originally released for MS-DOS in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(152704) 1998 SD4
Fifteen or 15 may refer to: *15 (number), the natural number following 14 and preceding 16 *one of the years 15 BC, AD 15, 1915, 2015 Music *Fifteen (band), a punk rock band Albums * ''15'' (Buckcherry album), 2005 * ''15'' (Ani Lorak album), 2007 * ''15'' (Phatfish album), 2008 * ''15'' (mixtape), a 2018 mixtape by Bhad Bhabie * ''Fifteen'' (Green River Ordinance album), 2016 * ''Fifteen'' (The Wailin' Jennys album), 2017 * ''Fifteen'', a 2012 album by Colin James Songs * "Fifteen" (song), a 2008 song by Taylor Swift *"Fifteen", a song by Harry Belafonte from the album '' Love Is a Gentle Thing'' *"15", a song by Rilo Kiley from the album ''Under the Blacklight'' *"15", a song by Marilyn Manson from the album ''The High End of Low'' *"The 15th", a 1979 song by Wire Other uses *Fifteen, Ohio, a community in the United States * ''15'' (film), a 2003 Singaporean film * ''Fifteen'' (TV series), international release name of ''Hillside'', a Canadian-American teen drama *Fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(36017) 1999 ND43 '', 2001
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36 may refer to: * 36 (number), the natural number following 35 and preceding 37 * One of these years of Gregorian or Julian calendars: ** 36 BC, 1st century BCE ** AD 36, 1st century ** 1936, 20th century ** 2036, 21st century Arts and entertainment * ''36'' (TV series), an American sports documentary show * "36", a 2002 song by System of a Down from ''Steal This Album!'' * 36 Quai des Orfèvres (film), a 2004 French crime film * "Thirty Six", a song by Karma to Burn from the album ''Almost Heathen ''Almost Heathen'' is the third studio album by the stoner rock band Karma to Burn, released in 2001 via Spitfire Records. It was the last album released before their seven-year disbandment in 2002. The album was reissued in 2022 by Heavy Psych So ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationship is found between a pair of objects (binary resonance). The physical principle behind orbital resonance is similar in concept to pushing a child on a swing, whereby the orbit and the swing both have a natural frequency, and the body doing the "pushing" will act in periodic repetition to have a cumulative effect on the motion. Orbital resonances greatly enhance the mutual gravitational influence of the bodies (i.e., their ability to alter or constrain each other's orbits). In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be self-correcting and thus stable. Examples are the 1:2:4 resonance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
