How Biofriendly is the Universe?

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Kepler-186f: artist’s concept. Image credit: NASA Ames/JPL-Caltech/T. Pyle

It’s obvious that our own planet is friendly to life, but what about the rest of the universe? Is the rest of space too cold and dark – or hot – to allow life to develop? Was the development of life on earth a hugely improbably event, or pretty much a forgone conclusion? The Nobel Prize-winning biochemist Christian de Duve spent the last few years of his career investigating this question, and came up with a surprising answer. In this post I’ll share five of the characteristics of life that he studied. Continue reading

Rare Earth: Why ‘simple’ life may be common in the universe, but animals may be unique to our planet

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Cropped from: Artist’s impression of a M dwarf star surrounded by planets. Credit: NASA/JPL-Caltech

Anyone who has watched enough nature documentaries will know that life can exist pretty much anywhere on Earth. One episode of the Blue Planet II series showed a hydrothermal vent – a crack in the mid-ocean ridge where hot gases and water pour out. Bacteria thrive in the scalding water around the vents, getting their energy from chemicals like hydrogen and sulphur, and enabling a rich ecosystem of bacteria-eating crabs, shrimps, and other animals to build up to such a density that it rivals Continue reading