S-type asteroids

Definition

S-type asteroids are a class of asteroids that are composed primarily of silicate minerals and nickel-iron. They are commonly found in the inner asteroid belt.

5 Must Know Facts For Your Next Test

1. S-type asteroids make up about 17% of all known asteroids.
2. They have relatively high albedo (reflectivity), typically between 0.10 and 0.22.
3. These asteroids are thought to be the source of many stony meteorites that fall to Earth.
4. Their spectra show strong absorption lines of silicate minerals, specifically olivine and pyroxene.
5. S-type asteroids are often located in the inner regions of the asteroid belt, closer to Mars than Jupiter.

Review Questions

• What percentage of known asteroids are classified as S-type?
• Which minerals dominate the composition of S-type asteroids?
• Where in the asteroid belt are S-type asteroids most commonly found?

Related terms

C-type Asteroid: A class of carbonaceous asteroids that have a very low albedo and contain a high percentage of carbon compounds.

M-type Asteroid: A class of metallic asteroids composed mainly of nickel-iron.

Albedo:

The measure of reflectivity or brightness of an object, expressed as a fraction or percentage.