The discovery of organic material that could be the remains of, or served as food for, ancient life on Mars is extremely exciting, but bitter-sweet (Mars rover finds signs of life … from 3bn years ago, 8 June). Companies such as SpaceX are hell-bent on putting human beings on the planet. But as reported, due to cyclical methane plumes, it is still unclear whether Mars is indeed a dead world today.
Currently, all Martian landing craft are sterilised before launch to prevent Earth-organism contamination, as some terrestrial bacteria can revive after decades in space. So landing a bacteria-laden human being on a planet that is not dead could erase the potential for one of the greatest discoveries in human history. Let us have regulation of Mars landers – and a temporary moratorium on human missions to the red planet.
Professor Todd Huffman
Oxford
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