taken from:
Earth-Asteroid Collision Formed Moon Later Than Thought
Richard A. Lovett
for National Geographic News
December 19, 2007
Scientists have long believed that the moon was formed by a collision between our planet and a Mars-size object.
Computer models have shown that in this scenario 80 percent of the moon’s material should have come from the asteroid, with only 20 percent from Earth.
But the new study of moon rocks collected three decades ago by Apollo astronauts, however, found that Earth and the rocks were too similar for that to be the case.
Earthly Material
The most likely explanation is that the moon was formed primarily of Earthly material, the authors say.
Lead author Mathieu Touboul of the Swiss Federal Institute of Technology in Zurich said there is another theory that may explain its formation.
“Alternatively, the material from which the moon eventually formed was a magma disk, connected to the Earth by a common atmosphere,” he said in a statement.
own words:
supports the idea that earth and moon were once connected, they share similar material. so the previous theory of and commet and the earth clashing wont work that well, cause then only a little of the material of the earth could have been transfered.
Gbach's Gblog 