Temperatures in PSRs might drop below -200C (-390F), making them prime locations to look for ice. A Nasa rover set to head to the Moon’s South Pole in late 2024, called Viper, will drive into some of these PSRs, switching on headlights to shed light – literally – on their secrets. The mission should tell us if there are “blocky chunks of ice” or “little crystals mixed into a sandy mix,” says Dan Andrews at Nasa’s Ames Research Center, Viper’s project manager.

Viper might not be the first mission to enter a PSR, however. A preceding mission called the Micro-Nova hopper, from the US firm Intuitive Machines, may be sent to the Moon earlier in 2024. While it lacks the instrumentation of Viper, such as a drill to dig into the surface, it will use its thrusters to “jump” into a PSR at the Moon’s South Pole, giving us our first ever glimpse inside.

These are not the only missions targeting the Moon’s South Pole though. A follow-up Indian mission in partnership with Japan, Chandrayaan-4, will also head here, while China has signaled its intent to land in this region and Russia has another planned South Pole mission.

Water ice is driving that interest. If it does exist in abundance and is accessible, it could be a valuable resource both for human settlements on the Moon and exploration farther into the solar system. If the ice can be stripped from the lunar soil it could be split into hydrogen and oxygen, a key component of rocket fuel or a potential source of drinking water and oxygen for human settlements.

“The simplest way to mine it is to dig up the icy soil and put it in some kind of oven to sublimate the ice,” says Kevin Cannon, an assistant professor in geology at the Colorado School of Mines in the US. “We could put enough propellant into a depot for a rocket to refuel and reach the outer solar system many times over. There’s also access to spots that are illuminated for up to 90% of the year, which gives good solar power for processing the soil into oxygen and metals like aluminium.”

These dreams of deep space travel and living on the moon are closer than one might think. In 2025 Nasa plans to land humans on the surface of the Moon on a SpaceX lander for the first time in half a century as part of its Artemis III mission. They will land at a currently unselected site at the South Pole and directly prospect for ice for the first time.

“The main objectives for that mission are learning how to land and operate in the polar regions,” says Jacob Bleacher, Nasa’s chief exploration scientist. Depending on the nature of ice discovered by previous missions like Viper at the South Pole, the astronauts will likely carry tools to collect some and return it to Earth. Future Artemis missions may then look to utilise this more keenly as a resource. “It is an iterative set of steps,” says Bleacher.

The prospect of other potentially useable minerals and metals on the Moon’s surface could also be mined and used by astronauts to construct the infrastructure they will need to survive there.