Mars is invoking our curiosity. It may be the planet humans will colonize someday. And maybe there once was life already. A new research led by UCL discovered extensive systems of fossilised riverbeds on an ancient region of the Martian surface. It supports the theory that Mars was once warm a wet some four billion years ago.
Scientists managed to identify over 17,000km of former river channels on a northern plain of Mars called Arabia Terra. Climate models have shown that in this area there was rain, but so far no proofs of water have been found. These riverbeds that scientists now identified prove that Mars was once warm and wet and thus, possibly, suitable for life. Scientists have noticed such channels that look like dried out rivers back in 1970’s, but not in this particular region.
Now an international team of scientists analysed high resolution imagery from NASA’s Mars reconnaissance Orbiter (MRO) spacecraft. These images cover a huge area in very high resolution. It allowed scientists to identify some valleys and inverted fossilised riverbeds. Similar channel systems are found elsewhere on Mars and Earth as well and are made of sand and gravel deposited by a river.
Land around these dried out rivers erodes and channels become inverted. These newly discovered channels are huge – about 30m high and up to 1–2km wide. Joel Davis, lead author or the study, said: “We think the rivers were active 3.9–3.7 billion years ago, but gradually dried up before being rapidly buried and protected for billions of years, potentially preserving any ancient biological material that might have been present”.
These are very important findings, because Arabia Terra was essentially one massive flood plain and if there was life on this planet, it must have been here. One of the channels, called Aram Dorsum, is a candidate landing site for the European Space Agency’s ExoMars Rover mission, which will launch in 2020. However, until that scientists will continue the research using even higher resolution imagery.
Mars may be the next home planet for humanity and it is important to get to know it better before sending first people there. Furthermore, some scientists believe that the processes that made Mars transition from warm and wet to cold and dry climate may help predicting the future of our Earth too. This is why scientists will continue researching history of this planet.