Smithsonian Uncovers Moon's Recent Tectonic Activity

New global map and analysis of small mare ridges reveals widespread recent lunar tectonic features.

Published on Feb. 20, 2026

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Scientists at the National Air and Space Museum's Center for Earth and Planetary Studies have produced the first comprehensive global map and analysis of small mare ridges (SMRs) on the moon, a characteristic geological feature of recent tectonic activity. The research, published in The Planetary Science Journal, shows that SMRs are widespread across the lunar maria and are geologically young, similar to previously discovered lobate scarps in the lunar highlands.

Why it matters

The discovery of widespread SMRs, formed by the same tectonic forces as lobate scarps, provides a more complete picture of recent contractional activity on the moon. This has implications for understanding the moon's interior, thermal and seismic history, and the potential for future moonquakes that could impact future lunar exploration and habitation.

The details

The research team compiled the first comprehensive catalog of SMRs, identifying 1,114 new segments across the nearside lunar maria, increasing the total known SMRs to 2,634. They found that the average SMR is 124 million years old, consistent with the average age of lobate scarps in the highlands. SMRs form via the same type of faults as lobate scarps, and the two features often transition into each other, suggesting a similar origin.

  • The research was published in The Planetary Science Journal on December 24, 2025.
  • The team's discovery of SMRs and their link to recent lunar tectonic activity builds on prior work by co-author Tom Watters, who in 2010 found evidence that the moon is slowly shrinking, causing the formation of lobate scarps.

The players

Cole Nypaver

A post-doctoral research geologist at the Center for Earth and Planetary Studies and the first author on the paper.

Tom Watters

A senior scientist emeritus at the Center for Earth and Planetary Studies, who previously discovered that the moon is slowly shrinking, causing the formation of lobate scarps.

National Air and Space Museum

The institution where the research was conducted by the Center for Earth and Planetary Studies.

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What they’re saying

“Since the Apollo era, we've known about the prevalence of lobate scarps throughout the lunar highlands, but this is the first time scientists have documented the widespread prevalence of similar features throughout the lunar mare.”

— Cole Nypaver, Post-doctoral research geologist (Mirage News)

“Our detection of young, small ridges in the maria, and our discovery of their cause, completes a global picture of a dynamic, contracting moon.”

— Tom Watters, Senior scientist emeritus (Mirage News)

What’s next

Upcoming lunar exploration programs, such as Artemis, will provide new data and insights that can further our understanding of lunar tectonics and seismic activity, which will directly benefit the safety and scientific success of future missions.

The takeaway

The discovery of widespread small mare ridges across the lunar surface, formed by the same tectonic forces as previously known lobate scarps, provides a more complete picture of the moon's recent geological history and the potential for future seismic activity that will be crucial for planning future lunar exploration and habitation.