Louisa Preston is a UK Space Agency Aurora Research Fellow, astrobiologist, planetary geologist and author based at Birkbeck, University of London. She spends her time thinking up ways to find life on Mars and exploring our planet’s most extreme environments. She has joined us at the Secret Garden Party to chat about microbes that live in the most extreme places on Earth such as the geysers of Iceland and red acidic rivers of Rio Tinto in Spain, and what they can teach us about what life might look like on other planets. Louisa is also a scientific adviser on the Intergalactic Travel Bureau show.