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Saturn's Moon Enceladus Has an Atmosphere
Dimentox writes "The Mercury News reports that the international Cassini spacecraft has discovered that Saturn's moon Enceladus has a significant atmosphere, NASA said Wednesday.
The icy moon's atmosphere may be created by volcanism, geysers or gases escaping from the surface or the interior, the space agency's Jet Propulsion Laboratory said.
Excluding Saturn's giant moon Titan, which was already known to have an atmosphere, it's the first discovery of an atmosphere on one of the more than 30 moons that orbit the ringed planet."
Link It should be noted that this isn't an atmosphere in the common sense. The air is continually created and lost due to internal sources and weak gravity.
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Wired article as proof
It's right here. Why that page wasn't linked to in the first place is beyond me.
Well, it'd be the 2nd moon ever with an atmosphere, and the 7th body in total with one (although Pluto probably has one, but that hasn't been proven).
Oh, it's almost definitely not organics. Encladeus is the most reflective large body in the solar system; it has to be almost pure ice and "gasses" (probably a tiny amount of oxygen from disassociation of water, maybe a little nitrogen, etc). In all likelyhood, it is geysers of water and/or steam that are creating the atmosphere.
"Here's a fun fact: the moon has turned to blood!" -- Newscaster, "Jesus Christ Supercop"
One of the passes was only 500km in height. Given that Enceladus is 500km in diameter, that leads me to think this is not a very thick atmosphere at all.
For comparison, Titan's 1.5 bar atmosphere is over 500km in height, and Titan's gravity is something like 100x that of Enceladus.
Not likely. The next craft to Saturn is undoubtedly going straight to Titan (the highest priority target in the Saturnian system - hence, Huygens), and that will take 10-15 years between design, construction, launch, and transit (unfortunately, Jupiter won't be available to assist spacecraft to Saturn again for a while). Without Jupiter, you either need a JIMO-style nuclear electric propulsion mission (expensive - JIMO was cancelled, darn them!), or need to accept 100-200kg payload, so don't expect many craft, either.
Perhaps in a 20-30 year timeframe, but for now the payloads are just too small for the investment to justify a trip to Enceladus when we could always go to Europa if we want to study an icy moon with subsurface liquids.
"Here's a fun fact: the moon has turned to blood!" -- Newscaster, "Jesus Christ Supercop"
Actually, the Cassini project is a co-op by NASA and the ESA (European Space Agency).
As I walk through the valley of death I fear no one, for I am the meanest sonova bitch in the valley!
Wrong moon. You want Mimas.
Show me on the doll where his noodly appendage touched you.
I've done some googling and have come across conflicting answers. One site lists only Titan as having an Dense atmosphere. Another lists Io, Europa and Triton with Tenuous(require regeneration) atmospheres as well. This new moon would seem to fall in that category.
And the planets?
Venus, Earth, Mars and maybe Pluto?
All the planets have an atmosphere of some sort. Mercury is trace, but there is something, a little something.
Venus to Pluto have atmo, so there are 8 bodies and Io, Callisto, Ganymede, Titan, Enceladus and Triton.
> Also, we've already kept people in space for long periods of time (or at least as long as long as a trip to Mars would hopefully take)
.38g on the other end or b) build a good rotating space station.
The longest stay in space seems to be 14 months (see http://news.bbc.co.uk/1/hi/sci/tech/374456.stm), which is not quite enough for most trips. In addition, I seem to remember that people were pretty screwed up afterward. We need to either: a) figure out how to keep people up there that long and have them be useful in
It's my guess that we'll end up with option (b), just because of the bone decalcification effects, neglecting the cardiac, psychological, muscluar, and other physiological effects. I'm not aware of any sufficiently detailed research on the subject, however.
Lea
A lot more than $100 billion has gone into propulsion research over the years. We simply don't know how to make better rockets. We have some ideas. Like fusion rockets. But they require breakthroughs (like fusion) for which we've spent even more money on.
How we know is more important than what we know.
Cassini is NASA. ESA was the Huygens probe.
If both NASA and the ESA want to share credit for the whole mission, fine, I'd go with that. But that didn't seem to be the attitude when the Huygens probe landed on Titan. When that happened, I recall the ESA being *very* specific that it was their probe- and their accomplishment, and not NASA's. I thought that was a bit rude. In other words they want to share partial credit for what isn't thiers, but they want to take total credit for what is theirs.
Just in case you actually care. The reason spinning space stations don't work is called coriolis acceleration. Basically spinning results in horizontal as well as vertical acceleration. The vertical is what you want. The horizonal is what disorients and makes astronauts sick. Now, if you happen to have a really really big wheel you can reduce the effects of coriolis acceleration but yeah, you need all that mass. One solution to this is to use a tether and spin a small station around a very very long axis (like kms). That's great an all but 1) it doesn't work in low earth orbit and 2) if the tether breaks you've got a nice uncontrollable projectile there. Then there's the actual problem of getting it spinning in the first place.
How we know is more important than what we know.