Rocks from Mars
Meteorites found on Antarctic Ice sheet
- which is ~ 1 mile thick
- no other rocks to confuse us
- meteorites are kept in “deep freeze” for 1000’s of years
- Most are normal meteorites
- wanderers in the inner solar system
- perhaps from the asteroid belt
- Important info on the early solar system
- oldest are 4.5-4.6 billion y old
- how the age of the solar system was determined
- tell us about composition and nature of planetesimals
- primordial building blocks of planets
- Some are not normal meteorites
- especially telling is the 16O:17O:18O isotope ratio
- Moon and Earth have the same ratios, which are different than Mars and asteroids
- This fact lead to acceptance of giant impact theory for Moon