The Martian (Water) Chronicles
June 28, 2012 --
Scientists believe that more than 3 billion years ago, Mars' northern plains were covered by an ocean that spread across more than one-third of the planet's surface.
Now, new analysis of two Martian meteorites suggests the inside of Mars is wet as well. The rocks came from a partly melted area of Mars' mantle, located just under the crust, and crystallized just below and on the surface.
An impact blasted the rock into space and it landed on Earth some 2.5 million years ago. The research indicates Mars' mantle contained between 70 and 300 parts per million of water. That's more water than what is found in Earth’s upper mantle, which is 50 to 300 parts per million.
Scientists guess that volcanic eruptions may have been the primary mechanism for getting water to the surface.
This artist's rendering, based on elevation data from an instrument on NASA’s now-defunct Mars Global Surveyor spacecraft, shows a Martian coastline as it may have looked 3.5 billion years ago.