A-type asteroids are relatively uncommon inner-belt
asteroid
An asteroid is a minor planet of the 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 or icy bodies with no atmosphere.
...
s that have a strong, broad 1
μm
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...
olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...
feature and a very reddish spectrum shortwards of 0.7 μm. They are thought to come from the completely differentiated
mantle
A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that.
Mantle may refer to:
*Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear
**Mantle (vesture), an Eastern Orthodox ve ...
of an asteroid, and appear to have a high density. One survey found that 7 similar A-, V- and X-type asteroids had an average density of .
[P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. ''Astronomy & Astrophysics'' 54, A56 ]
List
A-type asteroids are so rare that as of February 2019, only 17 had been discovered:
See also
*
Asteroid spectral types
References
External links
Mineralogic and Temperature-Induced Spectral Investigations of A-type Asteroids: (246) Asporina and (446) Aeternitas V. Reddy, Lunar and Planetary Science XXXVI (2005)
Asteroid spectral classes
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