With the prospect of a possible flight of colonists heading to Mars, a discussion about the possibility of geothermal energy usage on the Red planet has emerged. Is it pure science fiction or a glimpse into the future?

Elon Musk is planning to colonise Mars in the coming six years - and energy is one key problem for his crew of colonists, assuming that they get there, of course. There will need to be heat as well as light. Solar energy could provide part of it, but some have suggested that geothermal power could also have a role.

The story may have been a fantastic means of generating PR for Musk's ambitious plans, as there is almost no atmosphere as we know it on Mars. This has implications for the type of energy that would work on the surface. A geothermal power plant on its surface would need both an accessible source for heated fluids and also an overlying cold fluid source which would act as the 'heat sink'. 

For this type of system to work, the two must be located close to each other or ideally be co-located as reservoirs. There needs to be a very tight level of communication between the hot deep reservoir and the cool shallow reservoir - a situation unlikely to be available on Mars. Also, both fluid sources would need to be returned to their reservoirs for ongoing use. However, the reality is that they would simply disappear into the atmosphere and be lost.

It suggests that the news was mainly an enticing way to stimulate conversation about the bold colonisation plans. But it still raises the question: what will the Musk colonists use to power their new habitation if they do eventually make it to Mars?