A potash mine in Yorkshire is being used to test technology which could eventually go on to search for life on Mars.
Scientists believe that conditions in the Boulby mine on the north-east coast of England are similar to those on the Red Planet.
As part of the Mars Analogue Sites on Earth (Mase) project, a team of around 20 scientist will use the 0.8-mile deep mine to test instruments that could one day be used to detect long-dead microbial life underground on Mars.
Prof Charles Cockell, scientific co-ordinator of Mase, said: "If we want to successfully explore Mars, we need to go to Mars-like places on Earth. The deep, dark environment of Boulby mine is the ideal place to understand underground life and test space technologies for the exploration of Mars.
"In the process, we hope to aid the transfer of high technology from space exploration to safe, effective mining."
The team are hoping to examine micro-organisms that live inside the mine's underground ecosystem.
The project, which is believed to cost around £2m, is planning to examine non-oxygen-breathing microbes and to study how they might have survived on Mars.
The astrobiologists are also investigating how microbes get enough energy to survive without the energy of the sun, and if they can cope with the high level of radiation found on Mars.
The mine, in the North York Moors National Park, houses the Boulby Underground Laboratory, a subterranean facility that can conduct tests without interference from natural background radiation.