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April 09, 2011

Frozen comet had a watery past, University of Arizona scientists find

For the first time, scientists have found convincing evidence of liquid water in a comet, shattering the current paradigm that comets never get warm enough to melt the ice that makes up the bulk of their material.

Eve Berger from UA and her colleagues from Johnson Space Center in Houston, Texas, and the Naval Research Laboratory in Washington, D.C. made the discovery analyzing dust grains brought back to Earth from comet 81P/Wild 2 as part of the Stardust mission. Launched in 1999, the Stardust spacecraft scooped up tiny particles released from the comet's surface in 2004 and brought them back to Earth in a capsule that landed in Utah 2 years later.

"In our samples, we found minerals that formed in the presence of liquid water," Berger said. "At some point in its history, the comet must have harbored pockets of water."

Finding liquid water is always an important discovery, especially on a comet. This could possibly mean that comets are transporting liquid water from place to place.

To read more go to: http://www.astronomy.com/en/News-Observing/News/2011/04/Frozen%20comet%20had%20a%20watery%20past%20University%20of%20Arizona%20scientists%20find.aspx

Posted by skritt at April 9, 2011 05:44 PM


This brings further evidence for the theory that comets brought water to Earth. I wonder how the comet was able to contain liquid water, perhaps its orbit is elliptical enough that it comes fairly close to the Sun and some of the ice melts. One thing I've wondered is how much water can a typical comet carry? I wonder how many comets it would take to provide a plentiful water source on a planet or moon. And if clean water here on Earth runs low, could we replenish the supply by taking water from comets?

Posted by: brdoss at April 10, 2011 09:41 AM

I agree, this definitely proves the hypothesis that comets and asteroids brought water to our Earth during the heavy bombardment period. However, the one thing that is interesting is how water can even exist in a liquid form inside a comet, considering they're basically a huge ice ball. Its also interesting to think about how many comets and asteroids it took to bring all the water we have in our oceans to Earth.

Posted by: schultka at April 10, 2011 04:50 PM

It has been known for a long time that comets brought water to Earth. But this discovery rejected the notion that comets crashed on to Earth and melted to create our bountiful supply of water. What I am intrigued by is that with liquid water, is it possible that chemistry existed in these comets? Are there trace amounts of organic elements, too? Because we learned that comets exist in the Kuiper Belt or the Oort Cloud and rarely plunge into our solar system. So could life have started on these comets during the millions of years they orbited our solar system and then been introduced to Earth after a comet collided with Earth?

Posted by: jeffkong at April 11, 2011 05:24 PM

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