As humanity looks to the moon for science and economic opportunity in the coming years, understanding potential dangers lurking on the lunar surface could become increasingly important.
Ridges on the moon that signify moonquakes are the subject of a recent research paper, which delves into tectonic activity across the lunar maria, a vast network of dark plains that arose from ancient volcanic activity.
A team of researchers analyzed lunar formations called small mare ridges to create a global moon map, which is the first of its kind. The paper was originally published Dec. 24 in the Planetary Science Journal.
Cole Nypaver, a postdoctoral fellow at the National Air and Space Museum’s Center for Earth and Planetary Studies and one of the paper’s authors, told that the ridges that were identified were formed by faults in the lunar subsurface, which are associated with moonquakes.
“While those moonquakes are potentially hazardous for long-term lunar exploration missions or permanent outposts, they also present fantastic opportunities to learn more about the interior of the moon and how the moon formed,” Nypaver said.
The moon is shrinking
Another of the paper’s authors is a scientist named Tom Watters. Back in 2010, Watters discovered that the moon is slowly shrinking because its core is cooling.
The moon’s contraction causes disturbances on its surface. The crust gets compressed and forces material up along faults, which creates ridges, similar to how mountains form on Earth.
The most common of these ridges are called lobate scarps. They form on the lunar highlands, which are the bright spots we see when we look at the moon. But the small mare ridges only form in the lunar maria, which are the dark areas of the moon that contrast with the highlands.
This research is the first time scientists have documented the ridges throughout the lunar maria. In doing so, we now have a more complete understanding of the moon’s thermal and seismic history, which could give us a better idea of any potential moonquakes in the future.
“Our results represent the most globally complete understanding of recent lunar tectonism to date,” Nypaver said. “The presence of these additional tectonic features in the lunar maria suggests that the moon may have experienced more global contraction in the recent past than previously thought.”
A small mare ridge in Northeast Mare Imbrium taken by the Lunar Reconnaissance Orbiter Camera.
Moon missions
Humans setting up permanent footholds on the lunar surface have moved from science fiction to real plans for the near future. NASA’s Artemis II mission is set to launch in March at the earliest. And while this mission will only send astronauts to orbit the moon, future Artemis missions plan to land people on the lunar surface and build permanent infrastructure there.
University of Maryland professor Nicholas Schmerr helped NASA develop the Lunar Environment Monitoring Station for Artemis 3, which the crew of the third Artemis mission, currently scheduled for 2028, will deliver to the moon’s surface.
Schmerr said to that this instrument will detect seismic activity in the lunar south polar region.
“We’ll get a whole new picture of lunar seismic activity both on the South Pole and lunar farside,” Schmerr said.
LEMS-A3 is a station designed to be self-sustaining, and Schmerr will act as the instrument’s deputy principal investigator for the mission. The LEMS-A3 will assess “tectonics-related seismicity of the region and any hazard the moonquakes (or, for that matter, impacts) could pose to future longer-lived infrastructure,” Schmerr said.
Setting up shop
NASA isn’t the only one that’s looking to sustain long-term lunar operations. A company called Interlune also wants to set up mining operations on the moon to excavate helium-3, a valuable isotope that could be used for clean energy and quantum computers.
Elon Musk has been talking about building a moon base to launch AI satellites into orbit.
Getting up to speed on the areas of the moon that are more likely to experience moonquakes could influence where space agencies and private companies decide to build outposts in the future.
“There are several upcoming missions to the moon that will carry dedicated seismometers in hopes of detecting a moonquake from a small mare ridge or an asteroid impact on the moon,” Nypaver said. “By identifying a new population of tectonic features in the lunar maria, our work provides additional targets for those missions that seek to use moonquakes to better understand our closest celestial neighbor.”
