The Mars trojans are a group of Trojan objects that share the orbit of the planet Mars around the Sun. They can be found around the two Lagrangian points 60° ahead of and behind Mars. The origin of the Mars trojans is not well understood. One theory suggests that they were primordial objects left over from the formation of Mars that were captured in its Lagrangian points as the Solar System was forming. However, spectral studies of the Mars trojans indicate this may not be the case. [1] [2] Another explanation involves asteroids chaotically wandering into the Mars Lagrangian points later in the Solar System's formation. This is also questionable considering the short dynamical lifetimes of these objects. [3] [4] The spectra of Eureka and two other Mars trojans indicates an olivine-rich composition. [5] Since olivine-rich objects are rare in the asteroid belt it has been suggested that some of the Mars trojans are captured debris from a large orbit-altering impact on Mars when it encountered a planetary embryo. [6] [3]
Presently, this group contains 14 asteroids confirmed to be stable Mars trojans by long-term numerical simulations but only nine of them are accepted by the Minor Planet Center (†). [7] [3] [4] [8] [9] [10] [11]
Due to close orbital similarities, most of the smaller members of the L5 group are hypothesized to be fragments of Eureka that were detached after it was spun up by the YORP effect (Eureka's rotational period is 2.69 h). The L4 trojan 1999 UJ7 has a much longer rotational period of ~50 h, apparently due to a chaotic rotation that prevents YORP spinup. [12]
L4 (leading):
L5 (trailing):
A quasi-satellite is an object in a specific type of co-orbital configuration with a planet where the object stays close to that planet over many orbital periods.
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 L5 point) 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.
In celestial mechanics, a horseshoe orbit is a type of co-orbital motion of a small orbiting body relative to a larger orbiting body. The osculating (instantaneous) orbital period of the smaller body remains very near that of the larger body, and if its orbit is a little more eccentric than that of the larger body, during every period it appears to trace an ellipse around a point on the larger object's orbit. However, the loop is not closed but drifts forward or backward so that the point it circles will appear to move smoothly along the larger body's orbit over a long period of time. When the object approaches the larger body closely at either end of its trajectory, its apparent direction changes. Over an entire cycle the center traces the outline of a horseshoe, with the larger body between the 'horns'.
Mount Lemmon Survey (MLS) is a part of the Catalina Sky Survey with observatory code G96. MLS uses a 1.52 m (60 in) cassegrain reflector telescope operated by the Steward Observatory at Mount Lemmon Observatory, which is located at 2,791 meters (9,157 ft) in the Santa Catalina Mountains northeast of Tucson, Arizona.
In astronomy, a trojan is a small celestial body (mostly asteroids) that shares the orbit of a larger one, remaining in a stable orbit approximately 60° ahead or behind the main body near one of its Lagrangian points L4 and L5. Trojans can share the orbits of planets or of large moons.
In astronomy, a co-orbital configuration is a configuration of two or more astronomical objects orbiting at the same, or very similar, distance from their primary, i.e. they are in a 1:1 mean-motion resonance..
1173 Anchises is an unusually elongated Jupiter Trojan from the Trojan camp, approximately 124 kilometers in diameter. It was discovered on 17 October 1930, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany, and was the 9th such body to be discovered. The primitive P-type asteroid belongs to the largest Jupiter trojans, has an unusually smooth surface texture, the lowest spectral slope of all members of the Trojan camp, and a rotation period of 11.6 hours. It was named after Anchises from Greek mythology.
83982 Crantor, provisional designation 2002 GO9, is a centaur in a 1:1 resonance with Uranus, approximately 60 kilometers in diameter. It was discovered on 12 April 2002, by astronomers of the Near-Earth Asteroid Tracking at the Palomar Observatory in California, United States. This minor planet was named for Crantor from Greek mythology.
1867 Deiphobus is a dark Jupiter trojan from the Trojan camp, approximately 123 kilometers (76 mi) in diameter. It was discovered on 3 March 1971, by Argentine astronomers Carlos Cesco and A. G. Samuel at the Leoncito Astronomical Complex in Argentina, and later named after the Trojan prince Deiphobus from Greek mythology. The dark D-type asteroid is one of the largest Jupiter trojans. It is a member of the Ennomos family and has a long rotation period of 58.66 hours.
(101429) 1998 VF31 is a sub-kilometer asteroid that orbits near Mars's L5 Lagrangian point, on average trailing 60° behind it. Its orbit is highly stable, and was originally thought to be spectroscopically similar to 5261 Eureka, suggesting they may both be primordial Martian asteroids.
(311999) 2007 NS2 is an asteroid and Mars trojan orbiting near the L5 point of Mars.
2011 SC191 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2011 SL25, also written as 2011 SL25, is an asteroid and Mars trojan candidate that shares the orbit of the planet Mars at its L5 point.
2011 UN63, also written as 2011 UN63, is a Mars trojan, an asteroid orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2009 SE is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2018 EC4 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2018 FC4 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2011 SP189 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2011 UB256 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).
2016 CP31 is a small asteroid and Mars trojan orbiting near the L5 point of Mars (60 degrees behind Mars on its orbit).