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Jupiter's Great Dark Spot
Edball writes "For more than a century astronomers thought that the Great Red Spot was the biggest thing on Jupiter. Not anymore. Images from NASA's Cassini spacecraft have revealed something at least as large,
The Great Dark Spot."
In related solar system news, pajamacore writes "Space.com reports that the first extrasolar planet to have its atmosphere detected is having its gas envelope boiled off by heat and blown away by tidal forces. At present, the planet is 70% the size of Jupiter but its orbit is closer to its parent star than Mercury's is to our own Sun. It should be a treat to eventually see the planet's core and maybe it'll clue us in a bit to gas giant formation."
Didn't you hear about the radiation belt? The new theory is no life on Europa
Jason
ProfQuotes
Actually their lengths weren't conveniently adjusted to our measurement system but their proportions were 1 by 4 by 9 (the squares of the first three integers).
"Risked" is a strong word.
-l
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Yeah right. Learn some basic astronomy. Underneath the outer atmosphere is liquid metallic hydrogen. What does that mean? There is no true surface, and disturbance would quickly be smoothed over. Yes, many have theorized that there may be a small rocky core underneath it all, but it is insignificant compared to the the rest. I seriously doubt there'd be any surface features there, and even if there was, why would it reflect itself through such a dynamic atmosphere? I think not.
No the orbit would not get bigger and bigger. What force would act upon it? Another object with MORE gravitational force than the planets star would be needed. Mass being stripped off would affect the core though. It is often theorized that Jupiter has a rocky core 8 times the mass of the Earth, yet because of the emense pressure of the surrounding gases it is compresses it to a diameter of 11,000 KM, just smaller than the 12,800 KM diameter of the Earth. The estimated atmospheric pressure is near 70 million atmospheres with a tempature near 22,000 Kelvin. So as the gas is drawn away from the core it would expand and cool (because of a decreased Kelvin-Helmholtz effect). The heavy core would actualy look larger than it was in it's compressed form. This of course would take many many millions of years. I would specualte by that time we'd have discoverd other planets past that particular stage of life. I think a more interesting question would be as to WHY the atmosphere is being yanked by the star? It was thought that Jovian panets would only form at sufficient distances from a stars gravitaional force, otherwise all that Hydrogen and Helium would have been captured by the sun leaving a terrestial planet with a thinner atmosphere if any at all. Has the star expanded to a larger size or has the planet changed orbit? Another interesting factoid about Jupiter. The "Great Red Spot" was first detected in 1664 by Robert Hooke. Other similar but smaller and much more temporary storms are commonly seen. ~Z
Don't forget there are two other moons have been known to have similar subterranean worlds. Very strong evidence has been discovered to support the idea of subterranean oceans beneath the surfaces of two other Galilean moons, Ganymede and Callisto. While these would be colder, there is also far less radiation to wory about. With some luck, any of these three worlds may well host life, weither microbial or maybe something more complex.
For the first 1-2 billion years or so of life, there was no oxygen in the atmosphere. Oxygen only came about when photosynthetic organisms came about.
There are still a huge number of organisms in the world (bacteria) that not only do not use oxygen, but die in its presence.
Secondly, even on earth, there is life in water over 100 celcius, can grow in pH of 0, live in extremely salty water, produce energy from sulphur, or survive enourmous levels of radiation.
This is nothing like the theoretical possibility of silicon based life forms or other theories, it it actually exists on earth.
Its not so hard to believe that life can exist in similar or more extreme conditions elsewhere.
The standard objection to this is convection. While there certainly are levels in Jupe's atmosphere where the temp and pressure could possibly sustain life as we know it, Jupe's atmosphere is incredibly turbulent in the radial direction. Anything in the "pleasant" zone would quickly be thrust up into the outer layers or sink into the crushing layers.
That said, I wouldn't give up on life there either...
"Fifty million Americans can't be wrong," said Rep. Billy Tauzin. Gore - 50,999,897 Bush - 50,456,002
I actually worked at the Jet Propulsion Laborotory with Dr. West this past summer. The hexagonal spot in the middle is a result of the fact that this is a polar view of Jupiter created by combining 6 frontal images of jupiter. That is, we took six pictures of the front of jupiter, ignored all but the top half, changed the coordinates about, and put them back together to get an approximation of the polar view for that day. Since none of the pictures could actually SHOW the north pole, the area around it is placed with black.
The further from the pole you get, however, the more accurate the images, and where the dark spot is found the images are quite accurate.
Too bad I didn't read this article sooner, as most people will never see this comment.