A moderately bright, slightly reddish type of asteroid
believed to be composed largely of silicate minerals (the "S" stands for
"silicaceous") such as olivine and pyroxene.
S-class asteroids are quite common in the inner part of the main asteroid
belt, their proportion decreasing at greater distances from the Sun.
They have an albedo of 0.10 to 0.28 and a
reflectance spectrum that is flat at wavelengths longer than 0.7 micron.
Examples include 433 Eros, 951 Gaspra,
15 Eunomia (see Eunomia family),
and the 219km-diameter 29 Amphitrite. S-class asteroids may be the parent
objects of stony-iron meteorites.
|Animation of the rotation of 433 asteroid
AND OTHER MINOR PLANETS - TYPES AND GROUPS