This week, the European Space Agency announced that radar data collected by ESA’s Mars Express point to a pond of liquid water buried under layers of ice and dust in the south polar region of Mars. There is a long way between finding liquid brine pools on Mars and finding life. However, there might be a similar place on Earth, the Blood Falls in Antarctica that originate from a hypersaline brine groundwater environment that supports an anaerobic microbial ecosystem sustained by chemical energy. Professor Ian Hawes from Waikato University explains the importance of the discovery from Mars.