Re: Can liquid oxygen or other gases form naturally?

Bodies of liquid gasses are theorized on both Neptune and Jupiter (and some of it's moons). Unfortunately, their presence to date has only be inferred from other observations, but missions are being developed to more closely examine the make up of our planetary neighbors. Below are a couple of links for some pages discussing the make up of these two planets. It is believed that the massive atmosphere of Jupiter creates pressures so great that its inner layers may be made of something called "liquid metallic hydrogen." It is not quite a gas and not quite a liquid, but a slushy layer of elemental hydrogen that may be the cause of the persistent radio noise coming from the planet and Jupiter's incredibly strong magnetic field. Similarly, it is believed that, once you get through the atmosphere of heated gasses (hydrogen, helium, water and methane) that the rest of Neptune is comprised of molten rock, water, and liquid ammonia and methane.

You may check out these two websites for info. and for other possible sources.
http://www.solarviews.com/ eng/neptune.htm
http://www.jpl.nasa.g ov/galileo/Jovian.html

[Moderator's note: In general, you get liquids (as opposed to solids or gases) only for specific combinations of the surrounding conditions. For liquids to form, there generally has to be some atmospheric pressure. Look up "phase diagrams" in a chemistry textbook for more details.]