Top Astronomers Think Comet Could Harbor Life
Two top astronomers have a radical explanation for the unexpected features of Comet 67P/Churyumov–Gerasimenko, studied in detail by the European Space Agency Rosetta and Philae spacecraft since September 2014 – micro-organisms that shape cometary activity.
Philae made history last November after detaching from its Rosetta mothership and landing on to the surface of the comet, coming to rest close to a cliff or crater wall. After a communication problem, the probe “woke up” and restarted transmitting data to Earth.
We Could Have Found Evidence of Life on the Comet
The comet appears to have a black crust and underlying ice and images show large, smooth ‘seas’, flat-bottomed craters and a surface peppered with mega-boulders. The crater lakes are re-frozen bodies of water overlain with organic debris. Parallel furrows relate to the flexing of the asymmetric and spinning double-lobed body, which generates fractures in the ice beneath.
Dr. Max Wallis of the University of Cardiff and Professor Chandra Wickramasinghe, Director of the Buckingham Centre for Astrobiology, claim that these unexpected findings are best explained by the presence of living organisms beneath an icy surface.
They argue that these features are all consistent with a mixture of ice and organic material that consolidate under the sun’s warming during the comet’s orbiting in space, when active micro-organisms can be supported. The scientists will discuss their ideas today (Monday 6 July) at the National Astronomy Meeting at Venue Cymru in Llandudno, Wales.
According to the scientists, the micro-organisms probably require liquid water bodies to colonize the comet and could inhabit cracks in its ice and ‘snow’. Wallis and Wickramasinghe cite further evidence for life in the detection by Philae of abundant complex organic molecules on the surface of the comet and in the infrared images taken by Rosetta.
A few months ago the scientific instruments on board the Rosetta spacecraft provided evidence of carbon-bearing – organic – compounds on the nucleus of the comet 67P/Churyumov-Gerasimenko. The findings, detailed in the Science paper “The organic-rich surface of comet 67P/Churyumov-Gerasimenko as seen by VIRTIS/Rosetta,” are compatible with the presence of organic macromolecular materials – a complex mixture of various types of carbon-hydrogen and/or oxygen-hydrogen chemical groups, with little contribution of nitrogen-hydrogen groups. The full text of the paper is freely available on ResearchGate.
Neither Rosetta nor its lander are equipped to search for direct evidence of life after a proposal to include this in the mission was turned down. Professor Wickramasinghe, who is recognized as a leading expert on interstellar material and the origins of life and was involved in the mission planning 15 years ago, said: “I wanted to include a very inexpensive life-detection experiment. At the time it was thought this was a bizarre proposition.”
Dr Wallis said:
Rosetta has already shown that the comet is not to be seen as a deep-frozen inactive body, but supports geological processes and could be more hospitable to micro-life than our Arctic and Antarctic regions.
“If the Rosetta orbiter has found evidence of life on the comet, it would be a fitting tribute to mark the centenary of the birth of Sir Fred Hoyle, one of the undisputable pioneers of astrobiology,” added Professor Wickramasinghe.
Images from European Space Agency.