T-type asteroids are rare inner-belt

asteroid An asteroid is a minor planet of the Solar System#Inner solar system, inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic o ...

s of unknown composition with dark, featureless and moderately red spectra, and a moderate absorption feature shortwards of 0.85 μm. No direct

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or moon. When the original object en ...

analog has been found to date. Thought to be

anhydrous A substance is anhydrous if it contains no water. Many processes in chemistry can be impeded by the presence of water; therefore, it is important that water-free reagents and techniques are used. In practice, however, it is very difficult to achi ...

, they are considered to be related to P-types or D-types, or possibly a highly altered C-type. Examples of T-type asteroids include 96 Aegle,

114 Kassandra Kassandra (minor planet designation: 114 Kassandra) is a large and dark main-belt asteroid. It belongs to the rare class T. It was discovered by C. H. F. Peters on July 23, 1871, and is named after Cassandra, the prophetess in the tales of the ...

, 233 Asterope, and

308 Polyxo Polyxo (minor planet designation: 308 Polyxo) is a main-belt asteroid that was discovered by A. Borrelly on March 31, 1891, in Marseilles. It is orbiting the Sun at a distance of with a low orbital eccentricity (ovalness) of 0.04 and a period ...

. The infrared spectrum of the first three are similar to the mineral troilite, while 308 Polyxo is modified with hydration features. In 2010, the asteroid 596 Scheila was impacted by a projectile. The impact changed its spectrum from T-type to D-type, likely by exposing fresh material that was not weathered.

References

Asteroid spectral classes * {{Asteroid-stub

See also

References