Ask A Scientist© Environmental Earth Science Archive

 
 
 >> >>  name       Brenda
 >> >>  status     student
 >> >>  age        18

 >> >>  Question - "If the ages of Earth and MOon are nearly identical...why
 >> are most rocks
 >found on the Moon so much older than Earth rocks?
 >Can you answer this question for me? Thank you very much.


The rocks on the surface of the moon erode very slowly since there is no
atmosphere and no plate techtonics.  On the surface of the earth, erosion
and techtonic processes have changed the surface so rapidly, that we do not
have rocks on the surface of the earth as old as rocks on the surface of
the moon.

---Nathan A. Unterman
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Brenda,

Two big things I think contribute to this.  The earth is still continually
making new rock at the surface, i.e. volcanoes, but the moon is not.

The other thing is there is no life, little atmosphere, and no fluid water
on the moon, but on earth there are these, things which break down rocks by
erosion and other processes as well as bury them under layers of soil.

Don
Donald Yee Ph.D.                San Francisco Estuary Institute
180 Richmond Field Station,     1325 South 46th St. Richmond, CA  94804
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