May 9, 2013

Water on moon from earth

Water on the moon and the Earth originally came from the same place, an analysis of moon rocks suggests.

The discovery means the moon's water most likely originated from Earth itself, says Alberta Saal, the lead author of the study published Thursday online in Science.

That possibility is forcing scientists to reconsider the details of a long-held theory about how the moon formed in the first place.

The popular theory is that moon came together from debris left behind 4.5 billion years ago when a huge object — likely a Mars-sized planet-like rock — crashed into the "proto-Earth," the object that gave rise to our planet. According to theory, that impact would have generated so much heat that water and elements such as hydrogen needed to form water would all have boiled off into space, leaving the young Moon completely dry.

NASA has since found significant amounts of water both on and below the moon's surface, and some scientists had speculated it may have been brought by a comet long after the moon formed.

However, Saal, a geochemist at Brown University said the "simplest explanation" for his findings is that there was water on the proto-Earth at the time of the huge impact.

"Some of that water survived the impact, and that's what we see in the moon," he said in a statement.

Read More:cbc