More Water 'Out There:' Ice Found on Asteroid
Written by Nancy Atkinson
For the first time, astronomers have confirmed that an asteroid contains frozen water on its surface. Analysis of asteroid 24 Themis shows evidence of water ice along with organic compounds widespread across the surface. The scientists say these new findings support the theory that asteroids brought both water and organic compounds to the early Earth, helping lay the foundation for life on the planet.
Humberto Campins of the University of Central Florida in Orlando and colleagues recorded spectra of 24 Themis over a seven-hour period, and were able to study 84 percent of the rotational period of the spinning rock, Rob Cowen reported in Science News. Using NASA’s Infrared Telescope Facility on Hawaii’s Mauna Kea, the spectra revealed the consistent presence of frozen water as different parts of the asteroid’s surface came into view.
Analyses of the sunlight reflected off the asteroid also show that organic compounds are widespread on the surface, he added, including polycyclic aromatic hydrocarbons, CH2 and CH3.
The new finding corroborates earlier observations of the same asteroid by astronomers Andrew S. Rivkin and Joshua Emery who also used the Infrared Telescope Facility. Over several years, Rivkin and Emery had found evidence of frozen water in single spots on 24 Themis but had not studied the asteroid as it made one entire rotation. Together, the two teams’ findings reveal that the asteroid’s entire surface is coated with frozen water, Campins says.
The 160-kilometer wide asteroid averages a distance from the sun of about 3.2 times that of Earth’s. At that range, frozen water on the surface would readily vaporize, Campins said. That means the ice must be continually replenished, possibly by a reservoir of frozen water within the rock.
One possibility is that ice lies buried several meters below the surface of 24 Themis, and when hit by space debris, the ice makes its way to the surface. If this is the case, it could confirm that some asteroids resemble comets, becoming active suddenly and venting material into space when pockets of ice vaporize, Campins said.
Another option is that an action similar to the recent findings of water on the Moon, where solar wind interacts with a rocky body without an atmosphere to create H2O and OH molecules. Without an atmosphere, the body is exposed to solar wind, which includes hydrogen ions. The hydrogen is able to interact with oxygen in surface of the asteroid to create water molecules.
Campins shared his findings at the annual meeting of the American Astronomical Society’s Division for Planetary Sciences.
Source: Science News
Filed under: Asteroids
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October 8th, 2009 at 2:32 pm
Water's just everywhere these days, isn't it.
October 8th, 2009 at 2:39 pm
Actually, water's been everywhere the whole time. =D
October 8th, 2009 at 3:06 pm
Yea, we sure are on a role with water; now let's get started with finding life.
October 9th, 2009 at 12:53 am
Now we know we have access to water (albeit some extraction tech. may be required) let's start surveying those asteroids, and working out how to exploit their resources and get them back to lunar/earth orbit.. Once the money men can see real opportunities to get very rich indeed then the space industry will have some real investment and we will finally move out into the solar system.
October 9th, 2009 at 2:57 am
I think that is WAAY cool!
They've known for years now that the Earth is on the water poor side of the equation as far as the Universe is concerned….
So why does finding water everywhere surprise everyone so often?>??
October 9th, 2009 at 1:44 pm
"Another option is that an action similar to the recent findings of water on the Moon, where solar wind interacts with a rocky body without an atmosphere to create H2O and OH molecules. Without an atmosphere, the body is exposed to solar wind, which includes hydrogen ions. The hydrogen is able to interact with oxygen in surface of the asteroid to create water molecules."
Careful now… You're treading dangerously close to the "Electric Comet" model, which views comets as little more than asteroids on eccentric orbits being machined via cathode sputtering (that is to say, oxygen atoms being ripped from surface rocks [silicates] by strong electric fields) and OH / H2O in the coma being locally generated via recombination (machined Oxygen atoms picking up one or two Hydrogen atoms from the solar wind).
Feel free to look up Wal Thornhill's comments from way back:
(From: First Evidence of Comet Ice – What Does it Mean?)
"The flaw in the conventional approach is that only gas-phase chemical reactions and reactions induced by solar radiation (photolysis) are considered. The far more energetic molecular and atomic reactions due to plasma discharge sputtering of an electrically charged comet nucleus are not even contemplated [see below]. Yet this model solves many comet mysteries that are seldom mentioned."
"The hydroxyl radical, OH, is the most abundant cometary radical. It is detected in the coma at some distance from the comet nucleus, where it is assumed that water (H2O) is broken down by solar UV radiation to form OH, H and O. It is chiefly the presence of this radical that leads to estimates of the amount of water ice sublimating from the comet nucleus. The comas of O and OH are far less extensive than the H coma but have comparable density."
"The negatively charged oxygen atom, or negative oxygen ion, has been detected close to cometary nuclei. And the spectrum of neutral oxygen (O) shows a 'forbidden line' indicative of the presence of an 'intense' electric field. The discovery at comet Halley of negative ions puzzled investigators because they are easily destroyed by solar radiation. They wrote, "an efficient production mechanism, so far unidentified, is required to account for the observed densities." And the intense electric field near the comet nucleus is inexplicable if it is merely an inert body ploughing through the solar wind."
"Let's see how the electrical model of comets explains these mysteries. The electric field near the comet nucleus is expected if a comet is a highly negatively charged body, relative to the solar wind. Cathode sputtering of the comet nucleus will strip atoms and molecules directly from solid rock and charge them negatively. So the presence of negative oxygen and other ions close to the comet nucleus is to be expected. Negative oxygen ions will be accelerated away from the comet in the cathode jets and combine with protons from the solar wind to form the observed OH radical at some distance from the nucleus."
"The important point is that the OH does not need to come from water ice on, or in, the comet."
Same basic premise, eh?
I'm just saying, all the hubbub about surface sputtering seems to be making the electrical interpretation more plausible by the day…
Perhaps a reconsideration of the source of OH / H2O abundances in cometary comas would now be a reasonable area of investigation? Especially since comas have been shown to display "forbidden lines" in the spectrum directly indicative of the expected electric fields.
Hope this similarity in lines of thought doesn't make anyone too nervous. I just view it as an opportunity to expand the horizons of science a little. If the OH / H2O abundances can all be explained through very similar processes to those mentioned above (cathode sputtering), why not?
Best,
~MG
October 9th, 2009 at 3:13 pm
Wallace Thornhill is an academic fraud, and his so-called Electric Comet document proves it.
Apart from being intellectually dishonest, Thornhill (deliberately? cynically?) violates some of the most basic conventions in science, ones that he was most certainly taught at the University of Melbourne.
In terms of scientific content, what you write, MG, is little different than what your mate solrey wrote, in the JREF Forum (though solrey wrote at greater length) … and his ideas were ripped to shreds.
(Source: Electric Comet thread, in the Science section of the JREF Forum)
It has long since been conclusively demonstrated that the underlying corpus ("Electric Universe") is most definitely not science, and closely resembles creationism.
(Example: http://dealingwithcreationisminastronomy.blogspot.com/2009/08/electric-universe-creationism.html)
You know, MG, you'd gain some valuable respect if you simply took a certain DS to task for declaring that astronomy is bogus, instead of spamming internet fora with this sort of nonsense.
TPOD quote of the century: "There is no way that a measurement taken at only one end of a transmission channel can reveal changes that have occurred farther up the channel."
October 9th, 2009 at 5:25 pm
Just in case readers may not wish to go look at the JREF Forum thread (http://forums.randi.org/showthread.php?t=147374), here are some of the key points:
* asteroids and comets have very different densities; by MG's criteria, they should be the same (solar system 1, MG 0)
* by MG's criteria, tens or hundreds of thousands of asteroids should appear as comets, they don't (solar system 2, MG 0)
* "the spectrum of neutral oxygen (O) shows a 'forbidden line' indicative of the presence of an 'intense' electric field" – baloney (and MG knows this); forbidden lines occur when the density is very low, and has nothing to do with electric fields (physics 3, MG 0)
* "if a comet is a highly negatively charged body, relative to the solar wind" – more baloney (and MG knows this, being a keen student of plasma physics); the solar wind is a highly ionised plasma, and bodies in it cannot keep a significant charge for very long (there are exceptions, but they don't apply to bodies of the mass of comets, and with orbits like comets)
… and that's not even considering the lack of any numbers (rates of formation of H2O etc).
Now a reminder: IF there is no way that a measurement taken at only one end of a transmission channel can reveal changes that have occurred farther up the channel THEN the spectra Campins and colleagues recorded of 24 Themis are meaningless (i.e. there may be "water ice along with organic compounds", or there may be none at all; no one, and especially Thornhill, can tell).
October 9th, 2009 at 7:14 pm
There's an extraneous bracket in the URL; it should be:
http://dealingwithcreationisminastronomy.blogspot.com/2009/08/electric-universe-creationism.html
October 9th, 2009 at 7:16 pm
And one in the second too (grr!!)
http://forums.randi.org/showthread.php?t=147374