If all goes well, in just a couple of short years humans will return to the Moon for the first time in over half a century.
As NASA gears up to send teams of people to the lunar south pole by December 2024, one of the big questions has been: where, precisely, will these astronauts land?
We now have a better idea, with NASA revealing 13 candidate landing regions for Artemis III; the mission that will finally carry that precious human cargo.
"Selecting these regions means we are one giant leap closer to returning humans to the Moon for the first time since Apollo," says Mark Kirasich of the Artemis Campaign Development Division at NASA.
"When we do, it will be unlike any mission that's come before as astronauts venture into dark areas previously unexplored by humans and lay the groundwork for future long-term stays."
Each of the 13 potential landing regions is within 6 degrees latitude of the lunar south pole, a significant target of future exploration. This is a region of the Moon that no one has ever landed, and poses a significantly greater technical challenge than landings based towards the equator. For this reason, two uncrewed stages of the Artemis mission – Artemis I and Artemis II – must succeed before humans can safely launch.
But the lunar south pole will be worth the challenge. Craters in this region lie in permanent shadow, forming cold traps that barely exceed -163 degrees Celsius (-260 degrees Fahrenheit). It's hoped patches of water ice up to several meters thick could lie hidden in the darkness, providing future missions with a valuable resource to study and utilize.
The 13 landing regions, shown in the map above, are all roughly 15 kilometers (9 miles) squared, each harboring a number of possible sites around 200 meters (656 feet) in diameter. Potential landing zones are all close to (or even on) a crater rim or ridge – within moonwalking distance of a permanently shadowed region to ensure that astronauts have access to places that may contain water.
"Developing a blueprint for exploring the Solar System means learning how to use resources that are available to us while also preserving their scientific integrity," says exploration scientist Jacob Bleacher of NASA. "Lunar water ice is valuable from a scientific perspective and also as a resource, because from it we can extract oxygen and hydrogen for life support systems and fuel."
Each of the landing regions also provides access to sunlight for the six and a half Earth days the astronauts will be on the Moon. This is vital for the uninterrupted provision of solar power and minimal temperature fluctuations.
The craters currently being targeted are Faustini, Shackleton, de Gerlache, Amundsen, Nobile, Haworth, Malapert, and Leibnitz. Narrowing down the landing regions further, and the sites within them, will depend on the launch dates. These dates will determine the flight trajectories and environmental conditions, which will make some regions more favorable than others.
Meanwhile, Artemis I is gearing up to launch on 29 August, bound for a trip round the Moon and back again. This mission is uncrewed, but has test dummies on board to collect data on what physical effects future astronauts might experience on their epic journey.