Here's why scientists think alien life could be found on the Philae comet!

But others aren't so convinced.

The chase and exploration of comet 67P/Churyumov-Gerasimenko by the Philae lander has been one of the most exciting space stories of the last 12 months, and now a group of leading astronomers have claimed 67P could be home to a host of microorganisms living under the cold surface.

Uk scientists Chandra Wickramasinghe from the University of Buckingham and Max Wallis from the University of Cardiff say that the comet's distinctive features make it suitable for supporting alien life. According to simulations run by the academics, the black hydrocarbon crust, the seas of ice, and the flat-bottomed craters could well be harbouring "active microorganisms" at temperatures as low as minus 40 degrees Celsius.

The "icy structures, the preponderance of aromatic hydrocarbons, and the very dark surface" spotted by the Rosetta spacecraft point to some kind of life on the rock,Wickramasinghe claims. These characteristics "are not easily explained in terms of prebiotic chemistry," he told Rebecca Ratcliffe at The Guardian. "The dark material is being constantly replenished as it is boiled off by heat from the Sun. Something must be doing that at a fairly prolific rate."

Unfortunately, Philae itself may not be able to spot it, as the lander doesn't have the necessary instruments to detect life. Wickramasinghe, who was involved in planning the mission 15 years ago, thinks more should be done to find life outside our own planet: "Five hundred years ago it was a struggle to have people accept that Earth was not the center of the Universe," he commented. "After that revolution our thinking has remained Earth-centered in relation to life and biology. It's deeply ingrained in our scientific culture and it will take a lot of evidence to kick it over."

To give you some perspective, the two scientists say the 67P comet is potentially more hospitable to life than the Arctic and Antarctic regions of planet Earth. Wickramasinghe and Wallis set out their ideas earlier this week at the National Astronomy Meeting at Venue Cymru in Llandudno, Wales.

Due to the limitations of the European Space Agency technology on and around 67P, we may never know one way or the other, but the astronomers say that both Philae and Rosetta have spotted evidence of "abundant complex organic molecules" on the surface of the comet, further backing up the theory that some form of alien life may be clinging to the rock. 

But ohers aren't so convinced. "It's pure speculation," Rosetta project scientist Matt Taylor told Sarah Knapton at The Telegraph this week. "I think it is unlikely." Monica Grady, who worked on the design of the Ptolemy instrument installed on Philae,added, "I think it is highly unlikely."

The comet and its robotic passengers are currently around 284 million km (176.7 million miles) away from Earth and travelling at speeds of around 117,482 km/h (73,000 mph).