How Hot is the Moon? A New NASA Mission is About to Find Out

The Moon may be Earth’s closest neighbor, but it still holds many secrets beneath its dusty surface. While humans first set foot there over 50 years ago, our understanding of the Moon’s internal structure and thermal history remains incomplete. Now, with NASA’s Artemis program aiming to establish a sustainable human presence, a groundbreaking new instrument could revolutionize how we plan to live and work on the Moon.

This is where the new tool comes in.

Heat on the moon

The Lunar Instrumentation for Subsurface Thermal Exploration with Rapidity (LISTER)—scheduled for delivery to the lunar surface in 2025—will measure heat flow from within the Moon, helping scientists understand how our 4.5-billion-year-old satellite formed, how it cooled, and how its interior evolved.

Modern research, based on Apollo samples and data from missions like NASA’s GRAIL (Gravity Recovery and Interior Laboratory), shows that the Moon is not just a cold, inert rock. It has a complex interior, including a solid inner core surrounded by a molten outer core. By analyzing how heat travels through the Moon’s surface material (regolith), scientists can infer deeper thermal processes dating back to the Moon’s molten beginnings.

LISTER is designed to drill into the lunar soil, called regolith up to roughly three meters, collecting thermal data at multiple intervals. The instrument will measure two different aspects of heat flow: thermal gradient (how temperature changes with depth) and thermal conductivity (the subsurface material’s ability to let heat pass through it).

This is no simple task, however. The Moon’s regolith is a fine, dusty layer formed by countless impacts over millennia. Dust grains are jagged and abrasive, making drilling and subsurface measurements challenging. LISTER’s pneumatic excavation system tackles this problem by using controlled bursts of gas to clear material and steadily advance the drill.

Taking the moon’s temperature

Every half a meter, a delicate needle-like sensor will be inserted into the undisturbed soil to measure temperature. Inside this sensor, a platinum resistance thermometer records the soil’s natural temperature for 30 to 60 minutes. Repeating this process multiple times will produce a detailed heat-flow profile of the lunar soil.

“By making similar measurements at multiple locations on the lunar surface, we can reconstruct the thermal evolution of the Moon,” said Seiichi Nagihara, principal investigator for the mission and a geophysics professor at Texas Tech. “That will permit scientists to retrace the geological processes that shaped the Moon from its start as a ball of molten rock, which gradually cooled off by releasing its internal heat into space.”

These insights aren’t just academic—they’re vital for future exploration. The Artemis program aims to return humans to the Moon, establish bases, and prepare for missions to Mars and beyond. Knowing how heat behaves beneath the Moon’s surface could influence plans for underground habitats, resource extraction, and long-term scientific installations. If LISTER’s techniques succeed, they might also pave the way for similar missions on Mars and other planets.