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Galileo's Final Blaze of Glory
EccentricAnomaly writes: "CNN reports that the Galileo spacecraft is about to perform its last flyby of Io. Galileo will skim a mere 100 km above Io to enter a trajectory that crashes into Jupiter in 2003. This is to avoid the spacecraft running out of fuel and accidentally crashing into Europa which might contaminate it with any bacteria spores on Galileo. This is a real concern - Apollo 12 found bacteria on Surveyor 3 that survived two and a half years on the moon."
..has a lot more chances to survive on Europa which has Ice and presumably water. If you have read you Arthur C. Clarke you'd know that Jupiter is an "unlit" star so it's better suited to kill any leftover bacteria.
$HOME is where the
-- silver_p
Jupiter has no solid surface, It is a gas giant. Technicaly it is a Brown Dwarf- which is a star that never got large enough to start a fusion chain reaction. It is extremely unlikely that any sentient life could form there, especialy considering the gravity is strong enough to compress the hydrogen atmosphere into a liquid metal at it's core, which produces the strongest magnetic field in the solar system.
Europa, on the other hand, has everything life needs to flourish. Water- most likely in a huge ocean under the surface ice, and energy- mainly geothermic energy produced by the mammoth gravitational force exerted by jupiter (the same ones that make io the most volcanicly active body in the solar system), as well as a phenominal amount of magnetic flux produced by hydrogens metalic core.
Now if you ask me, I'd prefer to burn a probe up in a dead star then a moon which could possibly support life.
I found a fact sheet about this little rock. Looks kinda like the asteroid phobos. (We made a non-crash landing on phobos, but I never heard if they took off again)
The answer to your question is in 2061 Odyssey 3.
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IANARS (I am not a rocket scientist), but I don't think that Galilleo has enough fuel to attain escape velocity from the Jovian system. Therefore it would just keep on orbiting haphazardly until it crashed into something.
Tidal stresses, such as the ones that drive the volcanos on Io, may produce enough heat to produce liquid water under the surface of Europa. And all you need is heat, hydrogen, and CO2 to have life.
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Did you ever stop to think about how much radiation actually reaches Jupiter from other sources? If Galileo were to explode over earth, it's RTG (Radioisotope Thermoelectric Generators) would have a negligible effect. Worse case scenario on Earth: Galileo explodes in Earths atmosphere. The RTGs break up into particulate form (the RTGs are designed using ceramics fused with the nuclear P-238). Everyone's nuclear exposure is raised by something like .001. You get more radiation exposure EVERY DAY from RADON than that of any fallen radiation from an exploded spacecraft like Galileo.
Radioisotope Thermoelectric Generators
What is an RTG?
That's the point - it would keep orbitting *sending back images* until it crashed.
This is why I love Slashdot; everybody's an expert, I guess.
You realize that the same propellant that is used to power the spacecraft's engine is also used to keep the antenna pointed at Earth, don't you? This is the same propellant supply that is all but exhausted. Without this, the spacecraft and its payload are scientifically useless. The reason for intentionally crashing it is to prevent a scenario, however slim, where Galileo may intercept Europa at some time in the distant future. Despite what another poster has claimed, it is not at all trivial (or even possible) to put the spacecraft into a perpetually stable orbit in a system as complex as the Jovian one.
It's done its job. It's in its end-of-life phase, after which it will have no further scientific value to us. NASA's completely right on this one; let's end it.
We're going down, in a spiral to the ground
Ablative means (rough translation) burning off material to prevent the heat from getting through to things behind/under them. The shuttle uses special ceramic-based tiles that do not burn off, but absorb the heat and radiate it back out without transmitting much of the heat through their core to the vehicle 'under' them.
The shuttle does get 'hot' because of a large surface area effectively rubbed against a large number of air molecules at high speed, but ablative is not an accurate term to use for any part of the system. It's one of the improvements (in some ways!) from the Apollo capsule days.
I believe it was James Oberg who debunked this urban legend a while back-- the swabs used for taking the samples were contaminated by the researchers.