It's easier to set down a spacecraft near the moon's equator, so that's where all six Apollo landings occurred. But now, NASA has more ambitious aims.

In August, just ahead of the first launch attempt, NASA announced 13 possible landing sites, each in the south pole region, where water ice has been confirmed deep inside craters that never see sunlight. A crewed lunar flyby, Artemis II, is anticipated for 2024. And the first crewed landing, Artemis III, could come as early as 2025.

The sites "are some of the best places to go for lunar geology and understanding lunar ice and sampling lunar ice," says Bethany Ehlmann, associate director of the Keck Institute for Space Studies at the California Institute of Technology.

Kring calls the lunar south pole region "absolutely extraordinary geologic terrain."

"If you really want to understand the origin of the evolution of the solar system, there is no better place ... to go [than] the moon," Kring says. Because the moon has never had an atmosphere or flowing water, it is not subject to weathering and erosion and has thus preserved evidence of its origin, he says.

As technology has steadily improved in the decades since Apollo, the level of detail on the moon's surface revealed by such probes as the Lunar Reconnaissance Orbiter "is so extraordinary that we've already identified rocks on the lunar surface that we want the astronauts to collect," Kring says.