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is a small
orbits around the of Mars. Its orbit is very stable and is large enough that the Yarkovsky effect will not affect its orbit.
asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...
orbiting near the of Mars
Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...
(60 degrees ahead Mars on its orbit). As of April 2024, it is one of only two known asteroids to orbit the leading of Mars—the other being —although at least 15 other asteroids orbit Mars's trailing : The largest being 5261 Eureka, , and . Not only does orbit on the other side of Mars from other similar asteroids, its spectrum
A spectrum (: spectra or spectrums) is a set of related ideas, objects, or properties whose features overlap such that they blend to form a continuum. The word ''spectrum'' was first used scientifically in optics to describe the rainbow of co ...
is different as well, which is puzzling because all of the Martian
Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...
trojans seem to be in very stable orbits.
Orbit
orbits around the of Mars. Its orbit is very stable and is large enough that the Yarkovsky effect will not affect its orbit.
Physical characteristics
Due to similarity in the measured brightness of with other Martian trojans, it is thought to be a small asteroid with an effective diameter on the order of . Its spectrum suggests that it is anX-type asteroid
The X-group of asteroids collects together several types with similar spectra, but probably quite different compositions.
Tholen classification
In the Tholen classification, the X-group consists of the following types:
* E-type – with high ...
, which is different from 5261 Eureka and , and is somewhat puzzling since different mineral compositions suggest different origins for the two groups of asteroids. The long lifetime of the orbits for these asteroids makes the possibility of one or more of them being interlopers unlikely, however. This suggests that either one or more of the Martian trojans was captured in such a way as to give it a long-term stable orbit (and it is therefore not a primordial Martian asteroid), or that some fusion or combination of previous asteroids resulted in the presently observed ones. The Yarkovsky effect may provide a potential capture mechanism but not enough is known about the shapes of these objects to provide a useful Yarkovsky model.
See also
* 5261 Eureka (1990 MB) * * * * * * * * * * * * *References
External links
* * {{DEFAULTSORT:1999 UJ7 121514 121514 121514 19991030