London, Aug 31: Pluto may contain a subsurface ocean warm enough to host life, according to English physicist Brian Cox who also said that humans could be the only complex life in our galaxy.
Cox believes the tell-tale ooze of glaciers on Pluto's surface hints at the possibility of a subterranean sea warm enough to host organic chemistry.
"The New Horizons probe showed you that there may well be a subsurface ocean on Pluto, which means - if our understanding of life on Earth is even slightly correct - that you could have living things there," Cox told 'The Times'.
The New Horizons spacecraft completed a 3-billion-mile journey across the Solar System and performed a flyby of Pluto in July.
The spacecraft captured detailed images and other data of Pluto and also of its moons: Charon, Styx, Nix, Kerberos and Hydra. It is unlikely, however, that New Horizons would be able to tell for certain whether warm water exists beneath the dwarf planet.
Cox said that the most immediate prospect for finding evidence of life was on the moons of other planets closer to home.
"It's not as accessible, unfortunately, as Europa [a satellite of Jupiter] or some of Saturn's moons. Titan looks as though it's got a subsurface ocean now, and Enceladus throws liquid into space, so you can fly through that and see if it's got organics in it," he said.
Cox also said it was plausible that humans could be the only complex life in our galaxy. The biological "bottlenecks" on the way to multicellular organisms are so difficult to squeeze through that only a tiny fraction of the planets where life emerges will be home to anything more than the simplest biology, he said.
Cox added that science is telling us now that "complex life is probably rare."