Researchers have discovered evidence that there's a lot more water on Mars--at least on parts of Mars--than anyone previously thought. Using new technology, scientists examined the water content in meteorites from the planet, and it points to a lot of it in the Martian mantle.
The meteorites they studied are called shergottite meteorites, and they likely broke off from Mars about 2.5 million years ago. Even though the meteorites had a different elemental composition, the amount of water was consistent, bolstering the idea that they're representative of the planet as a whole.
We've actually known there's been water on the surface for a while, but how it got there was a little hazier. Now we have an idea: volcanoes sent it out. As Carnegie Institution For Science investigator Erik Hauri, who performed the analysis, explained in a statement:
There has been substantial evidence for the presence of liquid water at the Martian surface for some time. So it’s been puzzling why previous estimates for the planet’s interior have been so dry. This new research makes sense and suggests that volcanoes may have been the primary vehicle for getting water to the surface.
Water under the mantle also clues us in a bit to the planet's geological history, suggesting H2O played a role in its formation.
So how much water are we talking about? At least in the samples, a lot of it. On average, a little more than Earth has. The samples suggested parts of Mars have between 70 and 300 parts per million water, while Earth's mantle averages about 50 to 300 parts per million. Two questions it raises: Could Mars ever have sustained life in the past, and would this make it easier to do in the future?