Water Plume Detected At Dwarf Planet Ceres

astroengine writes "Astronomers analyzing data from the now defunct Herschel infrared space observatory have made a huge discovery deep inside the asteroid belt. Dwarf planet Ceres, the largest body in the region, is generating plumes of water vapor. 'This is the first time water vapor has been unequivocally detected on Ceres or any other object in the asteroid belt and provides proof that Ceres has an icy surface and an atmosphere,' said Michael Küppers of the European Space Agency in Spain and lead author of a paper published today (Jan. 22) in the journal Nature."

Comments

water vapor plumes != liquid water

[erice]

But as we understand it, water vapor plumes likely mean bodies of water; and so far, in nearly all cases, bodies of water do equal life.

Not in this case. According to TFA:

Astronomers think that as Ceres reaches the closest part in its orbit to the sun, the more intense sunlight causes its icy surface to sublimate (i.e. turn straight from ice to vapor without transitioning through a liquid phase) at a rate of around 6 kilograms (13 pounds) per second.

So, no liquid bodies. Just solids and gas.

Liquid water requires a substantial atmosphere, which Ceres lacks. At low pressure, ice converts directly to vapor and visa versa.

Re:water vapor plumes != liquid water

[symbolset]

The ice supposed to compose most of Ceres is thought to come from the formation of the solar system. Ceres is thought to have much of the water left in the asteroid belt, as it weight about one third as much as all the objects in the belt. It is believed to have a crust of muddy rock from late asteroid impacts and concretion which protects the inner ice core from the solar energy which would have long ago caused the ice to sublimate away on a smaller body in this region of the solar system. Since it is in the asteroid belt it is also believed to be impacted periodically, occasionally with strikes severe enough to puncture this shell, and that would result in regions of ice exposed which could cause these "plumes".

While that doesn't mean liquid water, that does mean vast quantities of exposed ice, and easy entry to the ice levels. When Dawn gets there it may find a sort of "swiss cheese" surface where instead of craters you have some holes in the crust which are open underneath to the vast icy world below, the parts in perpetual shadow still exposed ice, caverns going down whole kilometers below the surface. Imagine the sunlight as a needle poking into each crater at dawn and scraping through the ice across the longitude of Ceres until 4 hours later it is gone. It would dig a slot. The low gravity (.03 g) would prevent the slot from caving in. At the bottom of these holes would be a crystalline ice wonderland as ice subliming when exposed to the sun and the gaseous ice recrystallizing would create some of the most astonishing ice crystals you could imagine. And snow. The sides of the slot, untouched by the sun, would expose to what is supposed to be almost pure water ice.

Not liquid water, but very exciting still. If there was ever life on Ceres, that ice cannot hide the fact - and that would be a remarkable discovery.

Mining asteroids is a nifty idea but if I was going to mine asteroids I think I would want to stake a claim on this one. The shots from Dawn promise to be some of the most exciting NASA has ever produced.

Re:Water=life

[T.E.D.]

Not true. Life has been found at the bottom of our oceans where no light penetrates (or oxygen, for that matter). Some suggest it may even have started there. I don't know about that, but the current empherical facts are:

• We aren't really sure what life's requirements actually are
• Everywhere on earth there is water and we've looked, life exists
• We haven't yet looked for life in any liquid water outside of earth

So any theories about whether alien water might or might not have life are at best unproven.