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Galileo's Flyby of Almathea
An anonymous reader writes "The spectacular Galileo flybys of Jupiter, Europa and Io are largely credited with the discovery of frozen water ice and some of the earliest examples of non-solar (tidal) heating anywhere in our solar system. For the next 10 days, Galileo scientists are preparing for their next target: probing one of Jupiter's moons, Almathea, at the close-up range of 100 miles. Almathea is one of the most unusual moons in the solar system, because it gives off more heat than it receives from the Sun."
For those of us who aren't very much at home in astronomy and it's terms and who just want to see (relatively) pretty pictures; Celestia also has Almathea available for your viewing pleasure, along with allot of different stuff in our solar system and even beyond there. Besides, it's a pretty proggy... :)
Hate me!
The point is that 'ice' can be made from all sorts of liquids - water is just one of them.
But all ice is in a frozen state no matter what it's made out of. I just thing he was pointing out the redundancy of saying "Frozen Ice"
Ursula Andress, Catherine Deneuve, and Charo, twice...
To continue your rant philosophically...
We are ignorant when it comes to life. What exactly is life? We only know what life is within our world.
Astronomers get excited at the fact that we can find water on Mars and Europa, meaning they could have life, because our knowledge of life involves water. But, as far as we know, there could be life on the moon, we just aren't looking for it correctly.
If (or when, depending on your philosophy) we find extraterrestrial life, it will be when we aren't looking for it, IMHO.
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
Hell, has nobody noticed that the real name is Amalthea?
Where are your classics!?
She was the goat that nurtured baby Zeus = Jupiter!
Jupiter is by far the most interesting planet (with it's moons) to me, other than the Earth. More information as well as pictures can be found on NASA's site for the planet itself.
The Correct spelling is Amalthea.
It says so on the JPL's website.
Also Amalthea was a nymph that nursed Jupiter in mythology. This fits in with the naming of the other moons.
It looks like it was only misspelled once on the astrobio site which may be the cause of the confusion.
Ursula Andress, Catherine Deneuve, and Charo, twice...
s/Io/Europa/
I thought the quote was "All these worlds are yours, except Europa. Attempt no landings there" after Jupiter ignited to melt the ice...
"Information wants to be paid"
Jupiter is so heavy that it's inner reigions are incredibly hot - some think it's actually a star that just wasn't big enough to have it's own mass crush it's innards to the point where nuclear fusion occurs and the star is born. It's big enough, though, that the innards are squished to to superheat. It's this heat from the inside that makes Jupiter warm up.
The moon's heating is accounted for by tidal forces - Jupiter is just so flippin' MASSIVE that it's gravity stretches and squeezes the moon, and these tidal forces make it heat up.
The surface of Amalthea (sp.?) will be interesting to look at. I think it will have pronounced cracks on the surface where aeons of tidal forces have had their way.
No no no. Clarke envisioned Amalthea (a.k.a Jupiter V) as great big a spaceship, used by an extinct alien race to move to our solar system. See here.
Life is like a web application. Sometime you need cookies just to get by.
Sorry to pick nits, but the name is Amalthea (ah-mal-THEH-ah), it means "the Goddess Amal" (IIRC a Babylonian name for Astarte, the Moon goddess). She was the goat that nursed Jupiter (Zeus, actually) in Mount Ida, and whose horn the baby god pulled with his mighty force while playing with her. That horn is called the Cornucopia, or the Horn of Plenty, after Jupiter, ashamed at his own clumsiness, bestowed that gift on the goat as an apology.
The fact that it radiates more heat than it receives implies that there's some kind of heat source within the planet, something like a metal core not unlike earth's.
;).
When we're capable of artificially introducing something like that into a planet most likely, we're capable of building our own (planets, that is
Dimensions: The length of the spacecraft is 9 m and, with the high-gain antenna (HGA) deployed, is 4.6 m in diameter.
Ha! That's great! Except that the high-gain antenna failed to deploy. Fortunately, with some spacecraft reprogramming, Galileo will still acheive about 70% of its original science goals using the low-gain antenna.
I hold it, that a little rebellion, now and then, is a good thing. -- Thomas Jefferson
Well, ices can exist in the crystalline or amorphous phase. E.g. the water ice inside cometary nuclei is in amorphous form, and one can argue that it is technically not frozen, because it has originally been built from such tiny particles that there hasn't been a meaningful macrostate (BTW, did you ever create amorphous sulphur in the chemistry class?) to call it such. When amorphous ice is heated, it turns to the 'normal', crystalline phase, which more closely resembles our concept of 'frozen'. I don't know, however, whether the original poster tried to express this distinction.
Existence usually comes as a surprise (Idem)
Ever tasted dry ice cream? I thought not. Dry ice is carbon dioxide ice. In planetary physics, all volatile compounds in solid form are known as ices.
Existence usually comes as a surprise (Idem)
This really bugs me, when I see people say "life can't exist there, that planet is twice Earth's distance from its star..." and rubbish like that. Aarrgghh !
If you are ranting about the "rare earth hypothesis" you should remember that the authors believe that life is MUCH more common than was previously believed. However they believe that advanced life and advanced civilizations are MUCH rarer than previously believed and do require conditions substantially similar to earths. Even you own post basically makes some of the same assumptions - you see the heat from this moon as promising because that heat is one of the prerequisites for life, the rare earth hypothesis adds additional prerequisites which must be present for *advanced* life. There are those that simply assume without thinking that life must evolve on a planet substantially similar to earth. The rare earth hypothesis arrived at pretty much the same conclusion through serious thought on the subject. They may be wrong (we simply don't have enough data) but their reasoning is sound and not based on simple prejudice or ignorance.
Actually, Triton (Neptune's largest) does, too, IIRC. All the gas giants do as well.
In Amalthea's case (as well as Europa and Io), the moon is constantly being contracted and stretched by Jupiter's gravity, and those tidal forces generate heat in the moon's core. You can duplicate this effect by squeezing a piece of styrofoam in your hand and feeling it heat up.
Of course, all the gas giants have internal heat sources due to the immense gravity in their highly contracted solid cores. Neptune gives off way more heat and light than it receives from the Sun.
THE GOOD HUMOR MAN CAN ONLY BE PUSHED SO FAR
Bart Simpson on chalkboard in episode 2F18
The "Pluto Express" you mentioned is named New Horizons. And it's yet to be canceled. In fact, I sat in on a technical discussion of all its subsystems over the summer. It's still on track to launch sometime around 2007. However, Congress has yet to approve funding for New Horizons so its up in the air whether or not it'll actually fly. That said, development for the probe is still on going.
What depresses me is that for the Almathea flyby they've left the camera off to save the expense of the photo team salaries. About the only science that's gonna happen is measuring doppler shift change of the carrier signal from the probe as it gets close to the moon to refine its mass estimate. This is a real shame; Almathea has some kind of interesting chemistry going on that creates unusual bright red and green patches on its surface we have glimpsed only from afar 20 years ago with Voyager...
Celestia is a 3D space simulator much like OpenUniverse. It's avaible for both Windows and *nix OSes. In it, you can view all the planets, some moons, asteroids, and a fair number of stars. Here's a shot of Almathea. They release add-ons every now and then-- you can even download the recently discovered Quaoar!
"To confine our attention to terrestrial matters would be to limit the human spirit." -Stephen Hawking
Guess what? The same thing happens on Earth. The solid earth has tides of about 7-14cm each day, caused mostly by the moon. It does cause some heat, but not much. By far the most important source of internal heat for the Earth is radioactive decay, followed by heat of fusion (solidifying core) and recrystallization, IIRC.
"dry ice" is marketing term and has NOTHING to do with physics.
Indeed, I tried to stay on the same colloquial level as the previous poster. But I happen to be a space scientist with a Ph.D. in physics, and my field of study is, surprisingly enough, comets. And when planetary scientists discuss these things, they say water ice, methane ice, CO2 ice, et.c., to make it clear what they are talking about, since, as I said, all volatiles in solid form are called ices.
Existence usually comes as a surprise (Idem)