Posted on 02/21/2007 11:40:53 AM PST by NormsRevenge
WASHINGTON - Scientists taking their first "sniffs of air" from planets outside our solar system are a bit baffled by what they didn't find: water.
One of the more basic assumptions of astronomy is that the two distant, hot gaseous planets they examined must contain water in their atmospheres. The two suns the planets orbit closely have hydrogen and oxygen, the stable building blocks of water. These planets' atmospheres — examined for the first time using light spectra to determine the air's chemical composition — are supposed to be made up of the same thing, good old H2O.
But when two different teams of astronomers used NASA's Spitzer Space Telescope for this new type of extrasolar planet research, they both came up dry, according to research published in Thursday's edition of Nature and the online version of the Astrophysical Journal Letters.
The study of one planet found hints of fine silicate-particle clouds. Research on the other planet found no chemical fingerprints for any of the molecules scientists were seeking.
"We had expected this tremendous signature of water ... and it wasn't there," said the study leader for one team, Carl Grillmair of the California Institute of Technology and Spitzer Science Center. "The very fact that we've been surprised here is a wake-up call. We obviously need to do some more work."
Grillmair's colleague, Harvard astronomy professor David Charbonneau, said these surprising "sniffs of air from an alien world" tell astronomers not to be so Earth-centric in thinking about other planets.
"These are very different beasts. These are unlike any other planets in the solar system," Charbonneau said. "We're limited by our imagination in thinking about the different avenues that these atmospheres take place in."
Our own solar system has two planets without water in the atmosphere, Grillmair noted: Mercury, which doesn't have an atmosphere, and Venus, which is a different type of planet from the huge gaseous ones that would be expected to have the components of water in the air.
So far, scientists have found 213 planets outside our solar system, but only 14 have orbits that make it possible for this type of study; only eight or nine of those are close enough to see. Grillmair's team studied the closest, which goes by the catchy name HD 189733b. It's a mere 360 trillion miles from Earth in the constellation Vulpecula. The other planet, HD209458b, is about 900 trillion miles away in the constellation Pegasus and it's the one with the strange silicate cloud.
So where'd the water go?
Maybe it's hiding, scientists suggest. The water could be under dust clouds, or all the airborne water molecules have the same temperature, making it impossible to see using an infrared spectrograph. Or maybe it's just not there and astronomers have to go back to the drawing board when it comes to these alien planets.
The other finding on the more distant of the two planets seems to indicate that the atmosphere is full of silicon-oxygen compounds, said study lead author L. Jeremy Richardson of NASA's Goddard Space Flight Center.
"They'd be like dust grains and they would form clouds," Richardson said. And that cloud of silicates could be blocking the space telescope from measuring lower-lying water, Richardson and other scientists said.
This could get series.
Uh, at least one of the Moons of Jupiter is covered in a water ocean, frozen for several miles down.
I like it! This is more fun than listening to C2C.
Fundamentally wrong. It's all over the solar system. Some places have none or very little, other places are made of it.
http://nai.arc.nasa.gov/astrobio/feat_questions/silicon_life.cfm?video=bob
Here's a better explanation of what I was trying to convey, it has to do with the flexitility of the carbon atom and the ability of carbon chain based molecules to adopt specific conformations due to the chirality of Carbon that is lacking in every other atom of the group.
You obviously have no clue what you're talking about.
Huh...?
And the water ice on Mars doesn't count???
Re-read the article and compare to the assumption made about hydrogen found on Mars that they assume must be water. They made the same assumptions about the planets atmospheres and came up empty.
They finds 'signs' of water which is very different from finding water.
There is very strong evidence of water on Mars. As for hydrogen, it's all over the place, even in not-so-vacuum of space.
It still has to be discovered whether Europa has a liquid water ocean, some slushy stuff, or if the moon's water is frozen solid through and through. The cracks on the surface suggest that it could have liquid water seeping up, though.
Here's a prediction for ya: miles below the surface of Europa there is liquid water and a slush of methane hydrates.
I read that link and found a confusing pair of statements. It says that:
"silicon lacks...chirality, or “handedness.” then in the next paragraph it says:
"Some chemists believe that the chiral selection process in the pre-biotic “soup” might have been aided by a “handed” silica (SO2) surface."
In the first case are they referring only to handedness in silanes, not oxides?
In the first case are they referring only to handedness in silanes, not oxides?
I'm honestly not sure. I do know that the microbiological selection process in early formation favored one "hand" of simple organics over the other and so all life on earth at the molecular level reflects this. From my limited understanding Carbon is the only element that exhibits this in a favorable way in regards to protein conformations.
God could create other planets that live off of ANYTHING known or unknown!! Or when they earth has cooled or burnt up, God could start another earth-TYPE planet that HAS water....either way it's all up to God.
Practically all the Si on earth is in the form of SiO4 tetrahedra linked in various ways. It's the same on the moon, Mars, and meteorites. None of these carbon-like silanes. Also Si has nothing analogous to CO2, whose soluble & gaseous state is so convenient for photosynthesis and respiration. SiO2 is a crystalline solid, almost insoluble.
bump.
Yes, my brother-in-law is a chemical engineer, worked for Shell Oil until 20 years ago(25 years w/the company). He knows all that stuff : polysilanes, liquid sodium, etc. His favorite tune is : Oh, the world owes me a living...about welfare bum demonrats. And design screw-ups with equipment is : MANDATORY CASTRATION!!! He does culligan water treatment systems now.
What else do you want to know?
Uh, at least one of the Moons of Jupiter is covered in a water ocean, frozen for several miles down.
Sure would take a lot of energy to melt that ice and break down the hydrogen-oxygen bonds. The moon could then de-gas and perhaps create an atmoshere. According to Buck Rogers, anyway.
If the silicon atom can sustain such complex chemistries, well it would be an interesting find and something to look for in star searches like SETI. I was particularly interested in your comment about the physical aspects of silicon based aliens (the grays?) and how their silicon chemistry requires certain restrictions from normal stellar radiation. Would you elucidate the particular planetary protections needed for silicon based life to evolve on a planet, and perhaps the type of star system suited to same?
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