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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."
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.