A former potash mine is providing a test bed for technologies that can be used in the search for life on Mars.
Boulby mine on the North East coast, which is 0.8 miles deep, offers an environment similar to that on the surface of the Red Planet.
A team of 20 European scientists will use it to test instruments that might be able to detect living or long-dead Martian microbial life hidden underground.
Professor Charles Cockell, scientific co-ordinator of the Mars Analogue Sites on Earth (Mase) project, 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 mine's ecosystem has particular features and micro-organisms that are of special interest to astrobiologists.
The research programme aims to isolate and characterise non-oxygen-breathing microbes, study their responses to stresses they might have encountered on Mars, and investigate the potential for finding fossilised bugs on the planet.
Boulby mine, at the edge of the North York Moors National Park, houses the Boulby Underground Laboratory, a deep underground facility where studies can be conducted without interference from natural background radiation.
Work conducted at Boulby ranges from the search for dark matter, the mysterious invisible substance that makes up most of the universe, to studies of cosmic rays, extraterrestrial organisms, and life in extreme environments.