Trojan (astronomy)

Trojan (astronomy)

In astronomy, the adjective 'trojan' refers to a minor planet or natural satellite (moon) that shares an orbit with a larger planet or moon, but does not collide with it because it orbits around one of the two Lagrangian points of stability, "L4" and "L5", which lie 60° ahead of and behind the larger body.

The term originally referred to the Trojan asteroids orbiting around Jupiter's Lagrangian points. Subsequently objects have been found orbiting the Lagrangian points of Neptune and Mars. In addition, trojan moons are known to orbit the Lagrangian points of two of Saturn's mid-sized moons.

*The term Trojan asteroid usually refers specifically to Jupiter trojans, which are thought to be as numerous as the asteroids of the main belt.
*5261 Eureka, mpl|(101429) 1998 VF|31, mpl|(121514) 1999 UJ|7, and mpl|2007 NS|2 are Mars trojans [cite web|title=List of Martian Trojans|accessdate=2007-08-31|url=http://cfa-www.harvard.edu/iau/lists/MarsTrojans.html] .
*Six Neptune trojans [cite web|title=List of Neptune Trojans|accessdate=2007-08-31|url=http://cfa-www.harvard.edu/iau/lists/NeptuneTrojans.html] are known, but they are expected to outnumber the Jupiter trojans by an order of magnitude.

References

ee also

* List of objects at Lagrangian points
* Lagrangian point
* Trojan planet
* Trojan moon


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