We recently discovered the first direct evidence of comets bringing water to alien planets, and now we can go one step further. The planetary disk around the star TW Hydrae has enough water in it to support thousands of oceans.
Located 176 light-years from Earth in the constellation Hydra, TW Hyrdae is the closest star system to us that is still developing into a full-fledged solar system. That makes it an invaluable resource for exploring the origins of solar systems in general, ours very much included. The Herschel Space Observatory has found a huge cloud of water vapor in the far reaches of TW Hydrae's planet-forming disk.
While previous research has turned up evidence of similar water vapor clouds in the inner regions of the disk, this is the first time we've seen so much water so far away from the star. That means, unlike those earlier clouds, that this one is cold enough to eventually freeze and form comets. And it's those future comets that could one day bring water to the planets of TW Hydrae , and just maybe pave the way for the development of life in that solar system.
University of Michigan researcher Ted Bergin explains:
"This tells us that the key materials that life needs are present in a system before planets are born. We expected this to be the case, but now we know it is because have directly detected it. We can see it."
And fellow researcher Michiel Hogerheijde of Leiden University in the Netherlands adds:
"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."
Via the European Space Agency. Artist's impression by Tim Pyle, Spitzer Science Center, CalTech.