The mass varies of asteriods,larger than meteoriods; all asteriods together have about four percent of the mass of the moon. Asteriods have a distance from the sun between 270 million km and 6.7 billion km. Asteriods have a rotation period of 4.6 hours,and 4.8 Earth years to revolve around the sun. Asteriods do not have an atmosphere. Asteriods are made of clay,silicate rocks,nickel, and iron.
-May be grouped together in a belt between Mars and Jupiter; can be moved outside of the asteriod belt
-the 3 types of asteriods include: C type (chondrite),S type (stony),M type (metallic)
-Jupiter's massive gravity sometimes affect asteriods orbit
-More than 150 asteriods have a small companion moon ; some even have 2 moons
- The Galileo spacecraft flew by asteriods Gaspra in 1991 and Ida in 1993 (some asteriods have names)