NationMaster - Encyclopedia: Aten asteroid

The Aten asteroids are a group of near-Earth asteroids, named after the first of the group to be discovered (2062 Aten, discovered January 7, 1976 by Eleanor F. Helin). They have semi-major axes of less than one astronomical unit, placing them inside the orbit of Earth. Near-Earth asteroids (NEAs) are asteroids whose orbit intersects Earths orbit and which may therefore pose a collision danger, as well as being most easily accessible for spacecraft from Earth. ... 2062 Aten is an asteroid that was discovered at the Palomar Mountain Observatory by Eleanor F. Helin, who is now the principal scientist for the NEAT (Near-Earth Asteroid Tracking) project. ... January 7 is the 7th day of the year in the Gregorian calendar. ... 1976 is a leap year starting on Thursday (link will take you to calendar). ... Eleanor Francis Helin is an American astronomer, principal investigator of the Near Earth Asteroid Tracking (NEAT) program of NASAs Jet Propulsion Laboratory. ... In geometry, the term semi-major axis (also semimajor axis) is used to describe the dimensions of ellipses and hyperbolas. ... The astronomical unit (AU or au or a. ...

Nearly all known Aten asteroids have their aphelion greater than one AU. Those that have their aphelion entirely within the Earth's orbit are known as Apohele asteroids. As of May 2004 there are only two known Apoheles: 2003 CP₂₀ and 2004 JG₆. This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third planet outward from the Sun. ... Apohele asteroids are a subclass of Aten asteroids. ... 2004 is a leap year starting on Thursday of the Gregorian calendar. ... Discovered February 11, 2003, by the Lincoln Near-Earth Asteroid Research projects station at Socorro, New Mexico, 2003 CP20 (also written 2003 CP20), was the first asteroid known to have an orbit entirely within that of Earth. ... 2004 JG6 (also written 2004 JG6) is an unusual asteroid. ...

The smallest semi-major axis is that of (66391) 1999 KW₄, at 0.642 AU (its eccentricity of 0.688 takes it from a perihelion of 0.200 AU —well within Mercury's orbit!— to an aphelion of 1.084 AU), although 2004 JG₆ seems to have an even smaller one (0.635 AU; eccentricity 0.532 ranging from 0.297 to 0.973 AU —enough to cross Venus' orbit but not Mercury's). (66391) 1999 KW4 (also written 1999 KW4) is an Aten and Mercury-crosser asteroid discovered by LINEAR in 1999. ... (This page refers to eccitricity in astrodynamics. ... Atmospheric characteristics Atmospheric pressure trace Potassium 31. ... (*min temperature refers to cloud tops only) Atmospheric characteristics Atmospheric pressure 9. ...

For a brief time near the end of 2004, the asteroid 99942 Apophis (then known only by its provisional designation 2004 MN₄) appeared to pose a threat of causing an Earth impact event in 2029, but earlier observations were found that eliminated that possibility, although a very small possibility still exists for the years 2035 and 2036. 2004 is a leap year starting on Thursday of the Gregorian calendar. ... Close approach of Apophis on April 13, 2029 The white bar indicates uncertainty in the range of positions 99942 Apophis is a Near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a relatively large probability that it would strike the Earth in... The provisional designation of comets and asteroids are similar to each other: they both follow a pattern set in 1925 by the Minor Planet Center of the IAU. Historical designations At first, astronomers strove to assign symbols to the minor planets: 1 Ceres a stylized sickle 2 Pallas a lozenge... Artists impression of a major impact event. ... 2029 is a Common year starting on Monday. ... Centuries: 20th century - 21st century - 22nd century Decades: 1980s 1990s 2000s 2010s 2020s - 2030s - 2040s 2050s 2060s 2070s 2080s Years: 2030 2031 2032 2033 2034 - 2035 - 2036 2037 2038 2039 2040 Event January 8 - Near-Earth object 2002 AY1 will make a close approach to Earth. ... Centuries: 20th century - 21st century - 22nd century Decades: 1980s 1990s 2000s 2010s 2020s - 2030s - 2040s 2050s 2060s 2070s 2080s Years: 2031 2032 2033 2034 2035 - 2036 - 2037 2038 2039 2040 2041 Events India to overtake China as worlds most populous country. ...

Related topics

This is a list of all numbered Aten asteroids. ... The following is a list of current records for Aten_asteroids. ...

External links

Categories: Aten asteroids Minor planets, or planetoids are minor bodies of the solar system orbiting the sun that are larger than meteoroids (the largest of which might be taken to be around 10 meters or so across) but smaller than major planets (Mercury having a diameter of about 4880 km). ... Vulcanoids are hypothetical asteroids that may orbit in a dynamically stable zone between 0. ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earths orbit and which may therefore pose a collision danger. ... Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. ... The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... A trans-Neptunian object (TNO) is any object in the solar system with all or most of its orbit beyond that of Neptune. ... Damocloids are asteroids such as 5335 Damocles and (16746) 1996 PW that have long-period highly eccentric orbits typical of periodic comets such as 1P/Halley, but without showing a cometary coma or tail. ... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small body in the solar system that orbits the sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail -- both due primarily to the effects of solar radiation... Artists rendering of the Kuiper Belt and more distant Oort cloud. ... This image is an artists rendering of the Oort cloud and the Kuiper Belt. ... An asteroid moon is an asteroid that orbits another asteroid. ... Presentation of the Solar system (not to scale). ... This is a list of numbered asteroids, in sequential order. ... This page alphabetically lists the first thousand asteroids to be numbered, which are mostly in the main belt. ...