Avenue Autumn 2019

Messages from Mars

Our close neighbour Mars once had an abundance of water which has dried up and disappeared, apart from ice at its polar caps. What can this stark planetary evolution, over billions of years, teach us about the past, present and future of our own planet? The answers are hidden in Martian rocks hurled to Earth. 

Martin Lee is Professor of Planetary Science: “Mars rocks were ejected from the surface of the planet by meteorite or comet impact before falling to Earth. We know they’re from Mars because they have the same chemistry as the Martian atmosphere, the rocks are younger than most meteorites and the minerals they contain are very similar to those found by NASA rovers. These rock fragments are a rich source of information on the geochemistry and evolution of the planet, telling us what conditions were like on Mars when the rocks were formed.”

Using powerful analytical instruments which transmit a beam of electrons through a specimen to form high-magnification images, traces of water and carbon dioxide have been found in the rocks. This discovery suggests that carbon dioxide and water that were once abundant in the atmosphere were absorbed into the crust of the planet. The research could have implications for extended space travel and climate change on Earth. “In manned missions to Mars, we could be able to extract water from the rock, which would be easier than bringing water from Earth,” says Martin. “Also, if we could take carbon dioxide out of the atmosphere on Earth on a smaller scale and store it in our crust we could potentially regulate and mitigate the effects of climate change.”