MOON DAILY

- Lunar Rocks Suggest Meteorite Shower

http://www.spacedaily.com/reports/Lunar_Rocks_Suggest_Meteorite_Shower.html

Corvallis OR (SPX) Apr 13, 2006 - New age measurements of lunar rocks returned
by the Apollo space missions have revealed that a surprising number of the rocks
show signs of melting about 3.9 billion years ago, suggesting that the moon -
and its nearby neighbor Earth - were bombarded by a series of large meteorites
at that time.

To quote:

What is particularly intriguing, Duncan says, is that this apparent spike in meteorite activity took place about 3.8 to 4 billion years ago - an era that roughly coincides with when scientists believe life first began on Earth, as evidenced by the fossil record of primitive one-cell bacteria.

It is possible that life was introduced to Earth from one of these meteorites, Duncan said. Or it could have developed spontaneously once the bombardment subsided, or developed beneath the ocean near life-nurturing hydrothermal vents. The lack of evidence on Earth makes the analysis of moon rocks much more compelling. The meteorite activity that bombarded the moon likely struck our planet as well.