the average surface temperature is minus 94 degrees Fahrenheit (minus 70 degrees Celsius).
This is much warmer than would be expected of a comet that is covered in ice, so researchers suspect it is evidence that the comet has a somewhat dusty surface, possibly with ice patches.
The first dust grains ever retrieved from the surface of an asteroid now confirm that these minor planets are constantly shaped by a continuous barrage of high-speed microscopic impacts, scientists find.
The Japanese asteroid probe Hayabusasucceeded in returning more than 1,500 grains of dustfrom the asteroid 25143 Itokawa when it parachuted into the Australian outback in June 2010. Already, the samples from this 1,800 foot-long (550 meter) rubble pile have helped solve the longstanding mystery of where most meteorites striking our planet come from.
Japan prepares for second asteroid sample return
Although the first Hayabusa mission made history, it collected substantially fewer samples than expected because the spacecraft's rock-gathering device failed to function when the probe approached Itokawa.
Hayabusa also suffered from a crippling fuel leak, ion engine failures, reaction wheel problems, battery issues and a break in communications with Earth for two months, and Japanese officials grew concerned they would lose the spacecraft.
But controllers delayed Hayabusa's return to Earth by three years, buying time for engineers to devise a method of using the craft's remaining ion propulsion engines to control its orientation and guide the probe home.
When scientists opened Hayabusa's re-entry capsule after it landed in Australia, they found more than 1,500 tiny rock and soil grains, most of which were confirmed to be from Itokawa.
http://www.psrd.hawaii.edu/Aug11/Itokawa-particles.htmlThe Hayabusa spacecraft, flown by the Japanese Aerospace Exploration Agency (JAXA), returned samples from asteroid 25143 Itokawa on June 13, 2010. Though the sampling device did not operate properly, the mission was able to return a couple thousand particles, from a few- to a few hundred-micrometers across. A battery of laboratory analyses (electron microscopy, elemental analysis, and oxygen isotopic measurements) shows that the particles derive from materials like those in thermally metamorphosed LL group ordinary chondrites. Astronomical observations had classified Itokawa as a stony S(IV) type of asteroid.
The nature of S-type asteroids has been debated for decades; some astronomers argued that S-type asteroids are ordinary chondrites while others suggested that they were more likely to be differentiated objects (i.e., melted or partially melted to make igneous rocks). The problem was that we did not know enough about space weathering on asteroids to know how the spectra of chondritic or differentiated asteroids changed with exposure to micrometeorites and solar wind. The examinations of Hayabusa's treasure have settled the argument: S-type asteroid, Itokawa, indeed has an ordinary chondrite composition whose spectrum has been reddened by space weathering. This conclusion is supported by detailed studies of the surfaces of 10 Itokawa particles, half of which have glassy rims (5-50 nanometers thick) containing nano-sized particles of iron sulfide and metallic iron, signatures of space weathering.
Analysis of noble gases in three particles from the asteroid indicate that they were exposed on the surface of Itokawa for surprisingly short times, less than 8 million years. The Hayabusa science team suggests that the short exposure time indicates loss of particles into space through small impacts at the surprisingly fast rate of tens of centimeters per million years. This might not seem fast, but the asteroid, only 535 x 294 x 209 meters in size, would become
Frantic wrote:http://www.space.com/26843-rosetta-spac ... ne+Feed%29
They are confused again...
the average surface temperature is minus 94 degrees Fahrenheit (minus 70 degrees Celsius).
This is much warmer than would be expected of a comet that is covered in ice, so researchers suspect it is evidence that the comet has a somewhat dusty surface, possibly with ice patches.
ExactlyGenius Gone Insane wrote:I am like a pig in sh*t right now reading all these articles about how baffled scientists are having learned that comets are warm and rocky, not dirty snowballs.
So awesome!!!!
It only took them 30 years to accept that they were all cometary alcoholics drunk with delusion and lies! I find that baffling!
BINGOMetryq wrote:Keep in mind that the electric comet is far more than "comets are not dirty snowballs." We're talking about the vertical wall of catastrophism, and that's shifting gears without using a clutch for mainstream scientists. The mainstream will dig in its heels to avoid slamming into that wall at full speed. ("Toons, get's 'em every time!")
That means the gradualism of geology and evolution will be a train wreck. The repercussions will be extremely wide range, which is why astronomers are fighting this so hard.
The people on top right now will stay on top. They'll spin it so that they've been the ones pitching EU all along, while nut jobs like Velikovsky have been pushing warped space and dark matter. By the time they're done re-writing the history of science, the rules of Fizzbin will look simple.viscount aero wrote:The confidence in these institutions as authorities would otherwise suddenly drop.
Probably yes. They realize the things we are talking about. They are not dumb people, quite the contrary. They are dogmatic however and a threatened lot.Metryq wrote:The people on top right now will stay on top. They'll spin it so that they've been the ones pitching EU all along, while nut jobs like Velikovsky have been pushing warped space and dark matter. By the time they're done re-writing the history of science, the rules of Fizzbin will look simple.viscount aero wrote:The confidence in these institutions as authorities would otherwise suddenly drop.
Steve Smith wrote:There is still a lot to do before anything is published, so the experiment remains behind closed doors. This is so that misunderstanding and criticism don't spread through the net on the basis of incomplete data. A painter wouldn't want his work criticized when all he's done is put in the background and blocked-out his images.
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