Nearby planet-forming disk holds water for thousands of oceans

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For the first time, astronomers have detected around a burgeoning solar system a sprawling cloud of water vapor that's cold enough to form comets, which could eventually deliver oceans to dry planets.

Water is an essential ingredient for life. Scientists have found thousands of Earth-oceans' worth of it within the planet-forming disk surrounding the star TW Hydrae. TW Hydrae is 176 light years away in the constellation Hydra and is the closest solar-system-to-be.

University of Michigan astronomy professor Ted Bergin is a co-author of a paper on the findings published in the Oct. 21 edition of Science.

The researchers used the Heterodyne Instrument for the Far-Infrared (HIFI) on the orbiting Hershel Space Observatory to detect the chemical signature of water.

"This tells us that the key materials that life needs are present in a system before planets are born," said Bergin, a HIFI co-investigator. "We expected this to be the case, but now we know it is because have directly detected it. We can see it."

Scientists had previously found warm water vapor in planet-forming disks close to the central star. But until now, evidence for vast quantities of water extending into the cooler, far reaches of disks where comets and giant planets take shape had not emerged. The more water available in disks for icy comets to form, the greater the chances that large amounts will eventually reach new planets through impacts.

"The detection of water sticking to dust grains throughout the planet-forming disk would be similar to events in our own solar system's evolution, where over millions of years, these dust grains would then coalesce to form comets. These would be a prime delivery mechanism for water on planetary bodies," said principal investigator Michiel Hogerheijde of Leiden University in the Netherlands.

Other recent findings from HIFI support the theory that comets delivered a significant portion of Earth's oceans. Researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans.

HIFI is helping astronomers gain a better understanding of how water comes to terrestrial planets---Earth and beyond. If TW Hydrae and its icy disk are representative of many other young star systems, as researchers think they are, then the process for creating planets around numerous stars with abundant water throughout the universe appears to be in place, NASA officials say.

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A few million years and maybe we'll have a worthwhile neighbor. Very cool discovery, if not immediately helpful in the search for life.

You think one of them would hit Mars to create life by any chance?

It's in the realm of possibility of hitting Mars, but it's not something we'd likely see. Since the comet-building material is floating around a forming star 176 light years away, it'll first have to form into a comet, escape the gravitational pull of that star, travel through space towards Mars and successfully hit it.

"Nearby" is a rather relative term, and given the celestial speed limit of c, if it was traveling a few times faster than the Voyager probes it'd still take the better part of a million years to reach our solar system.

Very cool, It's interesting to know that we might see the formation of comets to create a planet with water in the far future.

As for the comet hitting Mars... the answer is no, it won't happen. I think it's probably the same odds of your atoms being in perfect alignment with the wall's so that you can pass through it...

You know, having water on a planet does not instantly equal life. You have to have the perfect distance from your star, the right size to block harmful UV rays, a moon to stabilize the oceans, etc.

OH FUCK, WHO TAUGHT RAYQUAZA SURF?

This actually does look interesting. Shame we won't be around to greet any intelligent life that comes from it if it makes, uh...

...gaiafall.