.png)
B-type asteroids are a relatively uncommon type ofcarbonaceousasteroid, falling into the widerC-group; the 'B' indicates these objects are spectrally blue.[1] In the asteroid population, B-class objects can be found in the outerasteroid belt, and also dominate the high-inclinationPallas family which includes the third-largest asteroid2 Pallas. They are thought to beprimitive,volatile-rich remnants from the earlySolar System. There are 65 known B-type asteroids in the SMASS classification,[2] and 9 in the Tholen classification as of March 2015.
Generally similar to theC-type objects, but differing in that theultraviolet absorption below 0.5 μm is small or absent, and thespectrum is rather slightly bluish than reddish. Thealbedo also tends to be greater than in the generally very dark C type.Spectroscopy of B-class objects suggests major surface constituents ofanhydroussilicates,hydratedclayminerals,organic polymers,magnetite, andsulfides. The closest matches to B-class asteroids have been obtained on carbonaceouschondritemeteorites that have been gently heated in thelaboratory.
The majority of asteroids that have been observed to displaycometary-like activity are B-types.[3][4] Some of these objects display indications of aqueous alteration in the past, and they may have incorporated significant amounts of water ice.[1]
Asteroid101955 Bennu is a B-type asteroid which is the target of theOSIRIS-REx mission. The mission seeks to characterize the asteroid by mapping the surface, studying theYarkovsky effect, and retrieving a sample of the asteroid to return in 2023. The spacecraft was launched in 2016 and has been at Bennu since December 2018.
Other B-type asteroids include:
| Main | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Distribution |
| ||||||||
| Classification |
| ||||||||
| Exploration | |||||||||
| Lists | |||||||||
| Related | |||||||||
