Not to be rude, but actually this is incorrect. At low pressures there is some odd behavoir, but on a planetary scale the melting point of water increases with increasing pressure. Ice has several different crystal structures called polymorphs that change as pressure increases. Each requires greater and greater temperature to melt.
This is a good page on the water molecule and its behavoir: http://www.lsbu.ac.uk/water/index2.html.
While it is very likely that the interiors of a couple moons in the solar system have subsurface liquid oceans, that does not indicate high enough temperature at depth to consider the interior warm or hot or capable of supporting life. Over geologic time these subsurface liquids (which are thought to be predominantly H2O) have more likely formed through interaction with surrounding rock/metal. As H2O reacts with its surroundings and incorporates various impurities (salts, ammonia, organic molecules) into its structure the melting point is decreased to the point that a liquid or fluid condition is possible at significantly lower temperatures. Although in the case of Ganymede (Jupiter's fourth moon), which posses an internally generated magnetic field, a dynamo action similar to Earth's core may exist providing heat. Whether this is the case on Titan is yet to be determined. The massive amounts of organic components there make it harder to determine if there is an internal heat source or if the mixture of organic compounds are naturally stable at those conditions creating the lakes and cryovolcanoes previously mentioned.
That depends on which form of ice you want to look at. Different ice structures (polymorphs) are stable at different pressures and temperatures. For example, at room temperature, Ice VII would require at least ~22000 atm to be stable. As temperature increases the pressure needed to keep that same ice structure increases.
A fantastic H2O Phase Diagram can be found here (http://www.lsbu.ac.uk/water/phase.html). At 300C (573 K) you can have ice; you just need a lot of pressure. That kind of pressure is in the several gigapascal range (x10^9 Pa, 1 GPa145,000 psi). Any ice that has a designation (e.g. Ice I, Ice Ih, Ice II, III, V, VII, X, etc.) has a set crystal structure. As you can see on the phase diagram you can have ice at very high temperatures if you have enough pressure. What is present on the planet mentioned in the article is strictly dependent on the pressure and temperature conditions there, which we do not really know.
I have a friend who is looking to attend the Air Force academy or go through the Air Force ROTC program at the University of Illinois. One of the questions that came up during a discussion of piloting skills and reaction times was asked by the Colonel (or whatever rank he was) in charge of the program:
"Do you play a lot of computer games?"
My friend's answer was ofcourse YES.
And the colonel replied "Then you should be fine."
I thought it interesting that even the Air Force has taken note of the fact that computer gaming helps concentration and coordination.
Slashdot Mirror
Not to be rude, but actually this is incorrect. At low pressures there is some odd behavoir, but on a planetary scale the melting point of water increases with increasing pressure. Ice has several different crystal structures called polymorphs that change as pressure increases. Each requires greater and greater temperature to melt. This is a good page on the water molecule and its behavoir: http://www.lsbu.ac.uk/water/index2.html.
While it is very likely that the interiors of a couple moons in the solar system have subsurface liquid oceans, that does not indicate high enough temperature at depth to consider the interior warm or hot or capable of supporting life. Over geologic time these subsurface liquids (which are thought to be predominantly H2O) have more likely formed through interaction with surrounding rock/metal. As H2O reacts with its surroundings and incorporates various impurities (salts, ammonia, organic molecules) into its structure the melting point is decreased to the point that a liquid or fluid condition is possible at significantly lower temperatures. Although in the case of Ganymede (Jupiter's fourth moon), which posses an internally generated magnetic field, a dynamo action similar to Earth's core may exist providing heat. Whether this is the case on Titan is yet to be determined. The massive amounts of organic components there make it harder to determine if there is an internal heat source or if the mixture of organic compounds are naturally stable at those conditions creating the lakes and cryovolcanoes previously mentioned.
That depends on which form of ice you want to look at. Different ice structures (polymorphs) are stable at different pressures and temperatures. For example, at room temperature, Ice VII would require at least ~22000 atm to be stable. As temperature increases the pressure needed to keep that same ice structure increases.
A fantastic H2O Phase Diagram can be found here (http://www.lsbu.ac.uk/water/phase.html). At 300C (573 K) you can have ice; you just need a lot of pressure. That kind of pressure is in the several gigapascal range (x10^9 Pa, 1 GPa145,000 psi). Any ice that has a designation (e.g. Ice I, Ice Ih, Ice II, III, V, VII, X, etc.) has a set crystal structure. As you can see on the phase diagram you can have ice at very high temperatures if you have enough pressure. What is present on the planet mentioned in the article is strictly dependent on the pressure and temperature conditions there, which we do not really know.
I have a friend who is looking to attend the Air Force academy or go through the Air Force ROTC program at the University of Illinois. One of the questions that came up during a discussion of piloting skills and reaction times was asked by the Colonel (or whatever rank he was) in charge of the program: "Do you play a lot of computer games?" My friend's answer was ofcourse YES. And the colonel replied "Then you should be fine." I thought it interesting that even the Air Force has taken note of the fact that computer gaming helps concentration and coordination.