which moon has water?

Answer 1

HOT OFF THE PRESS

Tltan (Saturn's largest moon) has water too.

On July 27, 2006 - just one week ago! - NASA confirmed the presence of lakes in Titan's north polar region.

Based on its bulk density of 1.88 g/cm3, Titan bulk composition is half water ice and half rocky material. It is probably differentiated into several layers with a 3400 km (2,040 mi) rocky center surrounded by several layers composed of different crystal forms of ice. Its interior may still be hot and there may be a liquid layer consisting of water and ammonia between the ice crust and the rocky core,

NEWS RELEASE FROM NASA

Cassini Finds Lakes on Titan's Arctic Region
July 27, 2006
(Source: NASA/JPL)

Lakes on Titan

NASA's Cassini spacecraft has found lakes on Saturn's moon Titan.

The lakes are most likely the source of hydrocarbon smog in the frigid moon's atmosphere. Finding the source of the complex soup of hydrocarbons in Titan's atmosphere has been a major goal for the Cassini mission and is a significant accomplishment.

Numerous well-defined dark patches resembling lakes are present in radar images of Titan's high latitudes taken during a July 22 flyby. At Titan's frigid temperatures, about minus 180 degrees Celsius, the liquids in the lakes are most likely methane or a combination of methane and ethane.

"This is a big deal," said Steve Wall, deputy radar team leader at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We've now seen a place other than Earth where lakes are present."

This area of Titan has been in winter's shadow since before Cassini arrived, and the spacecraft had not flown over it before. During the flyby, Cassini's radar spotted several dozen lakes as small as 0.6 miles wide, with some nearly 20 miles wide. The biggest lake is about 62 miles long and may be only partly wet.

"What we see is darker than anything we've ever seen elsewhere on Titan. It was almost as though someone laid a bull's-eye around the whole north pole of Titan, and Cassini sees these regions of lakes just like those we see on Earth," said Larry Soderblom, Cassini interdisciplinary scientist at the U.S. Geological Survey, Flagstaff, Ariz. "Titan has turned out to be like a musical crescendo -- each pass is more exciting than the last."

Titan has not yielded its secrets easily because the dense smoggy atmosphere makes it very difficult to obtain good visible images. Radar can penetrate the smog and obtain clear images.

Dark regions in radar images generally mean smoother terrain, while bright regions mean a rougher surface. Some of the new radar images show channels leading in or out of a variety of dark patches. The shape of the channels also strongly implies they were carved by liquid.

Some of the dark patches and connecting channels are completely black -- they reflect back essentially no radar signal, which means they must be extremely smooth and might contain liquid. In some cases rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates.

Scientists had predicted, but had no confirmation until now, that pools of liquid were contributing to the high concentration of methane and other hydrocarbons in Titan's atmosphere.

"We've always believed Titan's methane had to be maintained by liquid lakes or extensive underground 'methanofers,' the methane equivalent of aquifers. We can't see methanofers but we can now say we've seen lakes," said Jonathan Lunine, Cassini interdisciplinary scientist at the University of Arizona, Tucson.

Since lakes come and go with the seasons, they wax and wane over time. Winds might alter the roughness of their surfaces. Repeat coverage of these areas is expected to provide more information on these lakes. By passing over a lake in a different direction, Cassini may see the effect of prevailing winds in the changing brightness of the lake surface. On later passes toward the end of its prime mission, Cassini might see changes in the shape or size of lakes as winter yields to spring in the northern hemisphere.

Cassini's next flyby of Titan is on September 7. In October, Cassini's radar will look even closer to the north pole, searching for more lakes and mapping more of the polar region covered by these features.

The Cassini-Huygens mission is a cooperative project between NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington.

For images of the lakes and more information, visit: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov

Answer 2

A lot of the moons do. As some answers point out, even our own moon may have small amounts of water in some form at some places (at least one thought now is that astronauts can make their own water from some rocks and chemical processes on the moon).

Also Europa, indeed. It may have a planet wide ocean of salty water and chemicals underneath its icy crust.

Titan has frozen water, too, but the lakes contain ethane and/or methane if they contain any liquid at all. There may be liquid water beneath the surface of Titan, but that's not confirmed. There IS water ICE though.

Enceladus, at Saturn, has water that is erupting in jets from "tiger stripes" in the southern hemisphere. Most of the surface of Enceladus is water ice.

Lots of moons of the outer planets seem to have plenty of water in ice form on their surfaces. Charon, at Pluto, may be mostly water ice.

You can find out a lot about the fascinating moons of the solar system at SPACE.com

Answer 3

This is a good website about the solar system. The only known moon with water ice on the surface is Europa.

Answer 4

Short answer; nearly every small body further out than the asteroid belt is largely frozen water. Traces of water can be found in constantly shaded regions on objects with no appreciable heat transporting atmosphere closer in (such as the Earth's moon, and probably Mercury). Further out there will be a mix of methane and water ices about 2:1, and really massive objects will also have a nice lot of hydrogen and helium gasses.

Around Jupiter, Ganymede and Callisto also have water ice surfaces. (Ganymese is thought to have a salty ocean or slush reservoir deep down) Europa and Encladus have liquid water on the surface relatively frequently so their surfaces are "newer" and less polluted by stuff raining down from space, but all are essentially water, just like Mars is essentially silicon dioxide.

Anywhere in the universe where it is too warm to keep methane frozen and cool enough to keep water frozen, you will find a water surface. Here is why:

If you look at elemental abundances in the solar system, after hydrogen, helium and carbon, oxygen is the most abundant element. (Half as abundant as carbon, twice as abundant as nitrogen) Oxygen is most often going to combine with hydrogen due to hydrogen being the most abundant element. That means most of that highly abundant oxygen is gonna end up as water. Most of the highly abundant carbon is gonna end up as methane.

If the body can't hang onto its methane it will end up mostly water (the assumption being if has an insufficient gravity and temperature combo to hold methane, it does not have a prayer of holding onto hydrogen or helium.)

So, anything small out beyond the water "snow line" of the solar system but before the methane snow line will be more water ice than anything else. Keep in mind that most larger bodies are built up by smaller ones sticking together, which is why as you go inwards in the solar system you have more silicon/aluminum/magnesium oxides for building materials than anything else. (Metal hydrides are VERY reactive, so they oxidize quickly.)

Answer 5

Our own moon may have some frozen water in the permanently shaded craters at the poles.

Jupiter's moon Europa has a surface of water ice and its core may be liquid water.

Answer 6

Most of the outer moons of the solar system have a lot of water ice. (As a ratio of volume, they have far more water than the Earth does though most of it is frozen.) Folks have already mentioned Jupiter's moon Europa...but Saturn's moon Enceladus was recently discovered to be spewing geysers of water-ice from its southern polar region. Here's an article with some photos: http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=639

Answer 7

It is beleived 3 of the 4 gallilain moons of Jupitur (Castelio, Europa, and Gandymede) all have an ocean of ground water runing in them. The planet most considered to have water, however, is Europa. Im sure ypour mentioning that one.

Answer 8

From what people are saying about the outer Moons (of which there are 162 ie ignoring our Moon, Phobos and Diemos) which Moon doesn't have water?

Answer 9

Are you sure you mean Titania (Uranus' largest moon)? Its diameter (1577.8 kilometres) is only 45% of our moon, and as our moon is not massive enough to retain an atmosphere, I don't see how Titania could either.

However Titan (Saturn's largest moon) does have an atmosphere and does have water, so I think you probably mean Titan when you say Titania?

Answer 10

I think you're thinking of Jupiter's moon Europa.

Answer 11

one of jupiters moons...best chance of other life in our solar system. Jupiter gives off lots of heat acting like a sun for its many mooms..sorry I can't remember the name.