Life has been discovered nearly a mile and half underground, raising hopes bacteria might be able to survive deep beneath the surface of other planets.
Researchers found the single-celled organisms living inside coal beds more than 8,000ft (2,440 metres) below the seabed off the coast of Japan. It is the deepest life has yet been found beneath the ocean.
At those depths the spherical microbes have to survive huge pressures that would crush most organisms while having no access to light or oxygen often needed for life.
Instead, the bacteria scavenge the chemicals they need to survive by breaking down the hydrocarbon compounds in the coal around them.
Scientists from the International Ocean Discovery Program, who made the discovery, said the microbes also have sluggish metabolisms.
Evidence from spacecraft and rovers have not proved that the surface of Mars once flowed with water.
The most recent findings from Nasa’s Mars rover Curiosity has shown that, billions of years ago, a lake once filled a 96 mile wide crater it is now exploring.
Water is considered to be one of the most crucial ingredients needed for life and has raised the question that if life could evolve here on Earth, why would it not have done so on Mars.