Guest Post: A hostile start to life on Earth

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Pixabay

Life on Earth had a rocky start – literally. For hundreds of thousands of years the planet was a hellish place. This period in geological history is called ‘Hadean’, and it was thought that no living thing could have survived. Life emerged so soon after Earth cooled that scientists have wondered how it could have been possible – but new results this year tell a different story. Continue reading

Guest Post: Making the Molecules of Life

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© Christian Mehlführer, Creative Commons Attribution 2.5 Generic license

At what point did chemistry become biology? In what type of environment did this transformation take place? These are major questions for those seeking to understand the origins of life on Earth. Continue reading

Guest Post – Life’s Origin: Probable or Improbable?

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The blue marble, NASA

Are we alone in the universe? Is there alien life out there somewhere? These are questions that have long intrigued humankind. Answers have ranged from the optimistic postulate by Frank Drake forty years ago of more than 1,000 civilizations in our galaxy alone to the much more pessimistic opinion of the astrobiologists, Ward and Brownlee, in 2000 that complex life may be extremely rare in the universe at large. Whereas the latter authors contend that intelligent life may be scarce, they express the belief that simple (microbial) life is abundant in the universe. Continue reading

Guest Post: Life as old as the Earth? The earliest evidence for living things

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Cross-section of a fossil stromatolite © James St John, flickr, https://creativecommons.org/licenses/by/2.0/

The history of life on Earth is almost as long as the history of Earth itself. The most precise scientific dating methods tell us that our planet formed 4567 million years ago, although there are no rock samples preserved from this ancient and chaotic time. The oldest known Earth materials are about 4300 million years old, and are found in the remote deserts of western Australia. The oldest probable evidence for life on Earth has been dated between 3700 and 3800 million years, in west Greenland, and is so sophisticated that the history of life on earth must extend much further back. These observations suggest that life is a fundamental property of our planet, a feature which makes the Earth very different from its immediate rocky neighbours. Continue reading

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

Life in a Purposeful Universe?

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Supernova remnant in the Large Magellanic Cloud , by NASA’s Goddard Space Flight Center/Jenny Hottle

What does astronomy have to do with the living world? Is a vast universe really necessary to life? Any does science say anything at all about purpose? In today’s podcast (transcript below) I discussed these questions with astrophysicist Dr Jennifer Wiseman, who shared some of her personal perspectives. Jennifer is a person of faith who has spent time thinking about the questions about meaning and purpose that her work raises. For her, science does not compel belief in God, but it can vastly enrich the sense of a purposeful and awe-inspiring creation. Continue reading