The search for life on Mars – the closest planet to Earth that may harbour life – has been an enduring preoccupation since the earliest days of space exploration.
Dr Louisa Preston is a British astrobiologist and planetary geologist studying life in Earth's most extreme environments, hoping to someday find life on Mars.
Here, she talks about where on Earth we can search for Martian-like life – and what it might look like if we find it.
What's the best way to try and find out what life on the red planet might be like? Astrobiologist Louisa Preston believes creatures surviving our planet's harshest conditions may provide valuable clues.