Astronomers have proposed a novel explanation for the strange appearance of the comet carrying Europe's robot probe Philae through outer space: alien microscopic life.
Many of the frozen dust ball's features, which include a black crust over lakes of ice, flat-bottomed craters and mega-boulders scattered on the surface, were "consistent" with the presence of microbes, they said.
Observations by the European Space Agency's Rosetta comet orbiter have shown that 67P/Churyumov-Gerasimenko "is not to be seen as a deep-frozen inactive body, but supports geological processes", Max Wallis of the University of Cardiff said in a statement issued by the Royal Astronomical Society (RAS).
In fact, the comet racing towards the Sun at a speed of 32.9 kilometres per second "could be more hospitable to micro-life than our Arctic and Antarctic regions".
Wallis and his colleague Chandra Wickramasinghe of the Buckingham Centre for Astrobiology presented their theory on Monday to a meeting of the RAS in Llandudno, Wales.
They pointed to Rosetta's detection of complex organic material, which gave the comet its surprisingly super-dark and low-reflecting surface, as "evidence for life".