132 Aethra is a metallic

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 ...

and Mars-crosser on an eccentric orbit from the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

. It measures approximately 40 kilometers in diameter. It was discovered by

James Craig Watson James Craig Watson (January 28, 1838 – November 23, 1880) was a Canadians, Canadian-Americans, American astronomer, discoverer of comets and minor planets, director of the University of Michigan's Detroit Observatory in Ann Arbor, and awarded ...

in 1873 and is the first such Mars-crosser asteroid to be identified. As a Mars-crosser asteroid, Aethra is the lowest numbered asteroid to not have proper orbital elements due to recurring perturbations by Mars. It has a rather eccentric

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

that sometimes brings it closer to the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

than the

planet A planet is a large, Hydrostatic equilibrium, rounded Astronomical object, astronomical body that is generally required to be in orbit around a star, stellar remnant, or brown dwarf, and is not one itself. The Solar System has eight planets b ...

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 ...

. With an original observation arc of only 22 days, 132 Aethra was a lost asteroid between 1873 and 1922. The varying light curve of the asteroid implies an elongated or irregular shape for its body. It is named after Aethra, the mother of

Theseus Theseus (, ; ) was a divine hero in Greek mythology, famous for slaying the Minotaur. The myths surrounding Theseus, his journeys, exploits, and friends, have provided material for storytelling throughout the ages. Theseus is sometimes desc ...

Greek mythology Greek mythology is the body of myths originally told by the Ancient Greece, ancient Greeks, and a genre of ancient Greek folklore, today absorbed alongside Roman mythology into the broader designation of classical mythology. These stories conc ...

References

External links

* * Mars-crossing asteroids Aethra Aethra M-type asteroids (Tholen) Xe-type asteroids (SMASS) 18730613 {{Beltasteroid-stub Recovered astronomical objects