London - A comet shaped like a duck has already made history for being the first to be landed on by a spacecraft. Now scientists believe the comet, known as 67P/Churyumov-Gerasimenko, could be home to life.
Leading astronomers who have been studying the findings of the European Space Agency's Rosetta spacecraft and Philae lander believe the comet could support micro-organisms. They go as far as to suggest that the comet is more hospitable for life than our own polar regions.
They argue that the presence of such organisms is one way of explaining the comet's “distinct and unexpected features” on its body mass, including a black crust, underlying ice, flat-bottomed craters, and a surface “peppered with mega-boulders”.
Dr Max Wallis, from the University of Cardiff, and Professor Chandra Wickramasinghe, director of the Buckingham Centre for Astrobiology, argue that the comet's features are consistent with a mixture of ice and organic material that occur under warming from the Sun - when “active micro-organisms” can be supported.
Dr Wallis is due to present his ideas to the Royal Astronomical Society's National Astronomy Meeting in Llandudno. He will tell fellow scientists that the comet's crater lakes are refrozen bodies of water covered in debris, and its large parallel furrows relate to movement on the body that generates fractures in the ice below.
The Royal Astronomical Society (RAS) explains that both astronomers have created a “model that suggests micro-organisms probably require liquid water bodies to colonise the comet and could inhabit cracks in its ice and snow”.
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.”
These organisms reportedly contain anti-freeze salts, which are able to adapt to temperatures as low as -40C. Areas of the comet lit by sunlight have come close to this temperature since it has been under observation, when it travelled within 500 million kilometres from the Sun and weak gas emissions were evident, according to the RAS.
Dr Wallis and Professor Wickramasinghe believe that further evidence for life is that the spacecraft detected “abundant complex organic molecules on the surface of the comet”, captured by infrared images taken by Rosetta.
Professor Wickramasinghe said: “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.”
Rosetta and Philae have been used to observe the comet since September last year and Philae landed on the comet, first discovered 1969, in November last year. It was earlier in 2014 that water vapour was first detected coming from the surface by Rosetta and since then Churyumov-Gerasimenko has been at the centre of astro-biological research. In December, scientists reported that the composition of the water vapour is very different to that found on Earth.
The RAS findings could serve to support the theory that life on Earth may have first been initiated by comets. The “panspermia” theory suggests organic materials brought to Earth billions of years ago during a barrage of comets could have provided the compounds needed to evolve into living matter.
The Independent