Mars might have had water many years ago, but now Mars habitat make it impossible to have water on the surface of mars. If Mars was to have water it would need a thicker atmosphere so it wouldn't be as cold. Mars would need warmer temperatures to melt the ice to make water. If Mars had water it would also need thicker air so water wouldn't turn into vapor. If Mars had these things it would probably have water.
Where the water on Mars went is not fully known. But scientists have looked at the clues and have come up with some possibilities. The most likely possibility is that the water froze because in the winter Mars' temperatures are -225 degrees Fahrenheit. Another possibility is that the water went underground. A very strange but true possibility is that the water could have boiled away into vapor. This sounds weird because of Mars' thin air water boils quicker so water would only be needed to be hotter than 55 degrees to boil into vapor. After looking at all the possibilities scientists are still arguing over which possibility might have made Mars' water disappear. We do not know fully what level underground the water is but we think it's close enough to the surface for astronauts to dig up.
Long ago Mars had water, but where it went is not entirely known. We do know that one possibility is that the water is underground. Some proof about this is the underground rivers. We can tell how old the marks are by looking at the meteors that went through them. Some scientists believe that if all the water came to the surface it would flood Mars in a depth of 1000 feet. One scientist thinks that water on Mars may not have been created by rain or snow but by the ground. Machines have done tests and think the water is so close to the surface that astronauts could dig it up.
The harsh climates on Mars make it impossible for water to be on the surface, but before the water left it created channels and craters. The biggest canyon on Mars is about the size of the United States. This canyon was probably created by water. Another thing created by water were lakes. These lakes look a lot like craters on the surface of Mars. Channels were also created by water. Channels are stream-like lines, they're created by water rushing through them over the years. Mars' water created a lot of things before it disappeared.
