Posted on 09/07/2005 7:18:05 AM PDT by LesbianThespianGymnasticMidget
Millions of kilograms of fine dust particles and water and a "surprisingly high" amount of organic molecules sprayed into space when NASA crashed its Deep Impact spacecraft into Comet 9P/Tempel 1 on 4 July 2005, reveal a trio of new studies.
The observations bolster theories that comets may have seeded Earth with the raw materials for life and suggest they may be sponge-like – rather than hardened – at their cores.
On 4 July, about 80 telescopes on Earth and in space trained their sights on Comet Tempel 1 when a 370-kilogram copper impactor was sent hurtling into its path. Just after the smash, a bright vapour plume spewed from the surface at about 5 kilometres per second, followed quickly by a stream of particles that spread into a cone.
The cone appeared to remain attached to the comet's surface for about 22 hours before separating into a detached arc. Researchers used this gravitational attraction to estimate the mass and density of the comet's main body, or nucleus. They found that the 72 trillion kilogram-nucleus was extremely porous, with as much as 80% of its volume taken up by empty space.
"That tells me there is no solid layer all the way down to the centre," says Mike A'Hearn, the mission's principal investigator at the University of Maryland in College Park, US. He says he had expected that the ice might become denser towards the core of the nucleus, but that instead "probably all the way in, ice is all in the form of tiny grains".
A touch crumbly "It’s like a sponge, with a lot of cavities," agrees Horst Uwe Keller, an astronomer at the Max-Planck Institute for Solar System Research in Germany. He observed the event with Europe's Rosetta spacecraft and says the discovery confirms previous observations suggesting other comets are also porous. "When you touch it, it just crumbles under your hands."
Observers estimate the impact released about 5 million kilograms of water from beneath the comet's surface and between two and five times as much dust. There was so much dust, in fact, that mission members have not been able to see the impact crater with the high-resolution camera on the mission's flyby spacecraft, about 500 km away.
To add to the problem, that camera was malfunctioning but now image-processing techniques may have revealed a glimpse of the crater and team members may release the image later on Wednesday.
Building blocks The team estimates the impact blasted away a crater about 100 metres wide and up to 30 m deep. Crucially, organic molecules were among the material ejected. Neither the full range of molecules nor their abundances have been determined yet, but researchers say they have found a surprisingly high amount of methyl cyanide, a molecule seen in large quantities in another comet.
This supports theories that comets may have brought water and the building blocks of life to Earth, and the team hopes to eventually "identify all the species comets brought in abundance to early Earth", says A'Hearn.
The observations have also apparently ruled out another theory – that impacts with other objects may be responsible for the occasional stream of gas and dust seen coming off of comets. Although Tempel 1's surface is pockmarked with craters ranging from 40 m to 400 m across, astronomers watching the comet both before and after the impact noticed that it released the streams relatively often in spurts of activity apparently triggered by sunlight.
"I don’t think the hypothesis that outbursts are caused by impacts is really valid," says A'Hearn. "Probably comets undergo outbursts like this very frequently and the fact that everyone was looking intensively [at this comet] for an extended period allowed us to see phenomena that are probably common and weren’t seen before."
I expected something a little more exciting after reading the title. Still good stuff!
Is this how the aliens put life on Earth as Scientologists believe?
Actually, this has major implications for the oil industry.
Sustainable oil is probably more fact than fiction as evidenced by the fact that we've probably burned more oil than there was ever biomass that converted into hydrocarbon chains like oil.
The fact that hydrocarbons seem to be prevalent throughout the solar system may indicate that they are probably also prevalent here on earth, if somewhat far, far below ground.
So what you're saying is, this explains Bush's Plan to get us to Mars? It's to help Haliburton? The DUmmies are right? :-P
The density study is intriguing, and certainly makes sense considering cometary impacts in the vein of Tunguska leaving no crater.
A highly porous body would burn up in the atmosphere quite differently from a solid body, like a metallic meteorite.
No. Spaceships.
Yeah. a few hundred tons of ice flashed instantly into steam would make a pretty big boom...
Now there's a spin and a twist to the story that hadn't occurred to me yet.
Yes, absolutely. We must get to Mars so we can drill for oil. Probably less red tape on the Red Planet, and no caribou to disturb.
Actually, I think we can just drill deeper to find what we're looking for. There are quite a few oil fields that were considered played out until they suddenly refilled... from the bottom.
Was I the only one thinking "What did Clinton do this time?"
Yes. You're a perv...
;^P
Does that qualify the comet for a journalism scholarship?
One for the list...
Astroenvironmentalism: The Case for Space Exploration As An Environmental Issue
Ryder W. Miller
San Francisco, USA
.....................................
* * *
Since mankind made such a mess of this planet and is now paying the environmental price for the damage, this topic is of extreme importance because we must avoid making the same mistakes in space as we have on earth. At issue are the environmental consequences of the steps we are about to take in entering space. The adaptation of environmental concerns to developments in the exploration and commercialization of space fit surprisingly easily. Astroenvironmentalism is another re-formulation of the associated environmental concerns involving a space wilderness to protect, rather than a "frontier" to exploit.
* * *
SpaceflightNow.com:
Deep Impact comet mission producing surprises
NASA NEWS RELEASE
Posted: September 6, 2005
Painting by the numbers is a good description of how scientists create pictures of everything from atoms in our bodies to asteroids and comets in our solar system. Researchers involved in NASA's Deep Impact mission have been doing this kind of work since the mission's July 4th collision with comet Tempel 1.
"Prior to our Deep Impact experiment, scientists had a lot of questions and untested ideas about the structure and composition of the nucleus, or solid body of a comet, but we had almost no real knowledge," said Deep Impact principal investigator Michael A'Hearn, a professor of astronomy at the University of Maryland, College Park, Md. "Our analysis of data produced by Deep Impact is revealing a great deal, much of it rather surprising."
For example, comet Tempel 1 has a very fluffy structure that is weaker than a bank of powder snow. The fine dust of the comet is held together by gravity. However, that gravity is so weak, if you could stand on the bank and jump, you would launch yourself into space.
Another surprise for A'Hearn and his colleagues was the evidence of what appears to be impact craters on the surface of the comet. Previously two other comets had their nuclei closely observed, and neither showed evidence of impact craters.
"The nucleus of Tempel 1 has distinct layers shown in topographic relief ranging from very smooth areas to areas with features that satisfy all the criteria for impact craters, including varying size," A'Hearn said. "The problem in stating with certainty that these are impact craters is that we don't know of a mechanism by which some comets would collide with the flotsam and jetsam in our solar system, while others would not," he added.
According to A'Hearn, one of the more interesting findings may be the huge increase in carbon-containing molecules detected in spectral analysis of the ejection plume. This finding indicates comets contain a substantial amount of organic material, so they could have brought such material to Earth early in the planet's history when strikes by asteroids and meteors were common.
Another finding is the comet interior is well shielded from the solar heating experienced by the surface of the comet nucleus. Mission data indicates the nucleus of Tempel 1 is extremely porous. Its porosity allows the surface of the nucleus to heat up and cool down almost instantly in response to sunlight. This suggests heat is not easily conducted to the interior and the ice and other material deep inside the nucleus may be pristine and unchanged from the early days of the solar system, just as many scientists had suggested.
"The infrared spectrometer gave us the first temperature map of a comet, allowing us to measure the surface's thermal inertia, or ability to conduct heat to the interior," said Olivier Groussin, the University of Maryland research scientist who generated the map.
It is this diligent and time consuming analysis of spectral data that is providing much of the "color" with which Deep Impact scientists are painting the first ever detailed picture of a comet. For example, researchers recently saw emission bands for water vaporized by the heat of the impact, followed a few seconds later by absorption bands from ice particles ejected from below the surface and not melted or vaporized.
"In a couple of seconds the fast, hot moving plume containing water vapor left the view of the spectrometer, and we are suddenly seeing the excavation of sub-surface ice and dust," said Deep Impact co-investigator Jessica Sunshine, with Science Applications International Corporation, Chantilly, Va. "It is the most dramatic spectral change I've ever seen."
These findings were published in the September 9 issue of the journal Science, and presented at the Division for Planetary Sciences meeting in Cambridge, England. Mission scientists are filling in important new portions of a cometary picture that is still far from finished.
Article I
The exploration and use of outer space, including the moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all mankind.
Outer space, including the moon and other celestial bodies, shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies.
There shall be freedom of scientific investigation in outer space, including the moon and other celestial bodies, and States shall facilitate and encourage international co-operation in such investigation. Article II
Outer space, including the moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.
* * *
Article XI
In order to promote international co-operation in the peaceful exploration and use of outer space, States Parties to the Treaty conducting activities in outer space, including the Moon and other celestial bodies, agree to inform the Secretary-General of the United Nations as well as the public and the international scientific community, to the greatest extent feasible and practicable, of the nature, conduct, locations and results of such activities. On receiving the said information, the Secretary-General of the United Nations should be prepared to disseminate it immediately and effectively.
Article XII
All stations, installations, equipment and space vehicles on the Moon and other celestial bodies shall be open to representatives of other States Parties to the Treatyon a basis of reciprocity. Such representatives shall give reasonable advance notice of a projected visit, in order that appropriate consultations may be held and that maximum precautions may be taken to assure safety and to avoid interference with normal operations in the facility to be visited.
Article XVI
Any State Party to the Treaty may give notice of its withdrawal from the Treaty one year after its entry into force by written notification to the Depositary Governments. Such withdrawal shall take effect one year from the date of receipt of this notification.
http://www.state.gov/t/ac/trt/5181.htm#treaty
We should grab a couple of these bigger ones and drive them into Mars.
The we would need to think of a way to defend against solar wind, given the lack of a Martain molten metal core and resulting magnetic field.
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