Lunar Geology

If NASA’s ambitious lunar-exploration plans succeed, scientists will cover the moon with sensors—and find answers to several long-standing questions about the inner solar system

- BY ROBIN GEORGE ANDREWS

AT NASA’S “IGNITION” EVENT this March in Washington, D.C., the agency’s administrator, Jared Isaacman, made it clear that Artemis II is only the beginning of a larger U.S. effort to populate the moon with astronauts and resource-prospecting robots. If this quest advances at the breakneck pace Isaacman desires, then Earth’s celestial sidekick will also become a source of profound scientific revelations.

Despite the moon’s proximity, we know surprisingly little about it with much certainty. The Apollo astronauts hauled back moon rocks and left behind a few short-lived geological experiments, but most of our lunar knowledge comes from moon-orbiting satellites, telescopic observations from Earth and the handful of sample-return missions undertaken recently by China. Plenty of researchers are itching to use the moon as a Rosetta Stone for studying the origin and evolution of our world and the solar system at large. Earth’s tectonics, volcanism, oceans, atmosphere and life have all erased the geological records of the planet’s earliest eras. But the moon, lacking such tumult, has preserved its historical evidence. That makes the silvery orb “a perfect geological laboratory,” says Sara Russell, a planetary scientist at London’s Natural History Museum. With new lunar access, here are the biggest mysteries moon-focused scientists are hoping to solve.

How is the moon still geologically alive?

The churning heat deep within planets and moons is what gives them geological “life,” from volcanic eruptions and earthquakes to the uplifting of mountains and the excavation of ocean basins. But when the heat wanes, a world dies, geologically speaking.