A rock quarried on Orkney was blasted into space to find out if meteorites could carry primitive life from one planet to another.
An image of the unmanned Foton M3 spacecraft. Picture by ESA
One theory being tested is whether life could have arrived on Earth from Mars.
University of Aberdeen experts had the rock attached to an unmanned Russian craft and found life would probably only survive in a large meteorite.
Further details about the experiment will be revealed at the Highland Science Festival on 3 November.
A slab quarried from Cruaday, Sandwick, was sent to Vienna to be specially sculpted into the right shape.
Transformed into the size of bowler hat, it was then attached to the side of the European Space Agency's Foton M3 mission, which launched from Kazakhstan last month.
Professor John Parnell, chair in geology and petroleum geology at Aberdeen, studied what effect the heat of re-entry from space had on the rock, along with Dr Stephen Bowden.
Orcadian rock was selected because it was organic-rich and extremely hard.
Prof Parnell said primitive life could not survive a meteorite of small size because of the heat, but believed it could survive inside the centre of a larger one measuring tens of centimetres.
However, he said any bigger and the meteorite would hit the ground so hard that it would vaporize.
The Highland Science Festival runs until 17 November at venues in Inverness-shire, Dingwall and Applecross.
One event will focus on Loch Ness, while another will centre around a film made by photographer Raymond Besant about the fulmar seabird, with scenes featuring the seabird from St Kilda and Orkney, as well as the Netherlands and Aberdeenshire.