Slashdot Mirror
Saturn Moon Continues to Delight and Baffle
vic_1066 writes to tell us that BBC News is reporting on the many interesting discoveries made by the Cassini probe. The Saturn moon, Enceladus, apparently continues to provide confusion and excitement for scientists the world over. The Cassini probe has been making waves ever since its arrival to the Saturn system.
As usual, get the information straight from NASA
Press Release, Pictures
Throw the bums out!
C'mon, it's really simple:
::= "it is" | "it has"
it's
for ALL OTHER USES, there is no apostrophe in 'its'
Surely this simple rule isn't beyond the tech-heads here? For those of us that care about English this is as jarring a syntax error as anything that would barf a compiler. So do our parsers a favour and LEARN this simple rule.
Enceladus was male, as you can tell by the name. A female would have been named "Encelada," making the mexican food joke even better.
Good, inexpensive web hosting
This is probably EXTEMELY unlikey. The reason being that the half life of U235 (the fissionable isotope) is "only" 700 Myears (U238's is 4.5 Gyears). Therefore the original amount of U235 present in the protoplanetary solar system is ~99% gone (the solar system is 4.5 GY old). This is why the Oklo reactors are not going anymore, they existed 2 GY ago because back then the natural abundance of U235 in U ore was ~3% (and what's the concentration of U235 in nuclear reactors?....yup ~3%). I think this fact also VERY likely precludes the existance of a natural nuclear reactor at Enceladus now as well.
- "Hear that?! The percolations are imminent! Cease your ingress!"
Emphasis on kooky. Refer to this site for a nice debunking of some of Hoagland's claims. Of course, not everything is debunked (the man seems to come up with a new conspiracy theory every week), but it's enough to kill his credibility.
This means that the water ice either rapidly falls back to the surface, or else is the source of material for Saturn's icy F(I think) ring, which is basically a line of water ice circling Saturn.
What makes this discovery interesting is that in order for there to be a detectable atmosphere on Enceladus, there must be some process as it cannot last by itself.
Hopefully the Cassini mission will reveal that source in time.
All the moons, including this one are not newly found. It's an old moon, known for a very long time.
a ssini-051005.html
These interesting moons have one thing in common, they are huge. They have gravity and a core. Without gravity, there will be no atmosphere, and the core might produce geological energies etc. Especially this combination of a core with minerals, and an outer layer of ice/water are interesting in regards to life as this is the combination you need. It's just like Europa (at Jupiter).
Smaller moons might be discovered as time goes by, but if they have eluded detection so far, they only have a size that will deprive them of the above important features. When they are small, the become meteor like, and we might as well check out meteors.
So don't expect any new moons like this to be discovered. Only new information and details about the ones we already know.
In regards to "how many" the number will probably be defined by definition. How big should it be to be a moon? In a sense you might say the rings are millions of tiny moons, but most will probably not say they are within the definition. But what about the big chunks in the rings? Some of the chunks make tracks in the rings... are they considered moons?
http://www.nasa.gov/mission_pages/cassini/media/c
So far we have already discovered all the "big" moons.
-:) Oh no - not again.
www.rednebula.com
1) The volcanoes at Io's surface have nothing to do with plasma physics or MHD.
2) No volcanoes have "drifted around" the surface of Io.
3) There have been migrations of Ionian eruption plumes (the gas/dust "geysers" above the surface).
4) We can quite readily explain this with simple thermophysics. Plasma or MHD has nothing to do with it.
5) Some people have claimed that MHD has influenced the shape of plumes, but we can't reconcile that with the observations of WHERE the fields interact with Io.
6) Some have claimed that electric currents can cause the elevated temperatures of some of Io's volcanoes, but they haven't done the simple math to know that even at 100% efficiency, there simply isn't enough energy available, and AGAIN, the field lines don't intersect the high temperature volcanoes.
Theory is fine, but if your pet theory can't handle the observations, go back to the theory--the observations are rarely "wrong".
Not sure what the hell this has to do with plasma physics or MHD. Electrical currrents don't do a damned thing to effect morphology. Same with craters. Same with IMPACTS into comets and subsequent ejection of materials.
Are you really claiming that high energy particles accelerated by the nearly non-existant magnetic field of Mars is causing flat-bottomed craters?! Wow! They must be moving really fucking fast.
Not sure what you mean that "these guys" never studied plasma fluid dynamics. If by, "these guys", you mean planetary scientists, cosmologists, or astronomers (all VERY broad fields), "they" invented or extended just about any new branch physics (I'm talking real science, with perdictions and ways to test the predictions) you care to talk about.
Who the hell modded that post "insightful"?