The Moon is still shrinking as its interior cools, causing the crust to contract and form young tectonic ridges across the maria that trigger shallow moonquakes.
Recent mapping reveals 1,114 previously unrecognized ridges, bringing the total to 2,634. These features are relatively young, averaging 124 million years, indicating ongoing tectonic activity throughout the lunar near side.
Understanding these seismic risks is vital for future missions like Artemis. Identifying active faults in the lunar maria helps researchers choose safer landing sites and better understand the moon’s thermal history.
Understanding the Moon is still shrinking
The Moon is still shrinking because its interior cooling causes the single outer shell to contract, thrusting rock blocks over faults to create small mare ridges.
These active tectonic landforms are distributed throughout the dark plains, serving as potential sources for moonquakes that threaten future astronaut safety.
Researchers identified 1,114 new ridges using high-resolution camera data. These features represent geological activity from the most recent 20% of the moon’s thermal and seismic history.
Global Tectonic Mechanisms vs. Earth
Unlike Earth’s plate tectonics, the moon has a single outer shell where stress builds up as it contracts. This compression thrusts rock blocks over one another along faults, creating lobate scarps and small mare ridges rather than traditional mountain ranges or ocean trenches.
Systematic Mapping of Small Mare Ridges
A comprehensive catalog now lists 2,634 ridges, confirming their widespread presence in the dark plains. This data completes the picture of a dynamic, contracting world with young geological features formed in the last billion years.
| Feature Type | Avg Age | Primary Location |
| Small Mare Ridges | 124 million years | Lunar Maria |
| Lobate Scarps | 105 million years | Lunar Highlands |
| Tectonic Segments | Recently Mapped | Near Side Maria |
Scientific importance and theories
Research linking these ridges to internal cooling supports the theory that the moon remains geologically active.
The Moon is still shrinking, which means thermal contraction is a persistent force shaping planetary surfaces even without complex plate tectonics, providing a globally complete perspective on recent tectonism.
Thermal Contraction and Surface Evolution
Interior cooling drives the formation of these ridges, mirroring the development of highland scarps. Because the Moon is still shrinking, these young surface features provide a record of the moon’s recent seismic and thermal history, helping scientists understand the interior behavior of small planetary bodies.
Seismic Hazards for Artemis Missions
- Mapping identifies active fault lines to avoid during habitat construction.
- Shallow moonquakes may occur wherever small mare ridges are present.
- Seismic activity impacts the safety and success of long-term lunar exploration.
- Researchers suggest moonquakes are triggered by global contraction forces.
Implications and what comes next
Scientists will monitor these features to refine risk assessments. As the Moon is still shrinking, identifying active faults is critical for the safety of future outposts and habitats.
Conclusion
Evidence from the latest global mapping confirms that the Moon is still shrinking through a continuous process of internal cooling. These findings help ensure the safety of upcoming lunar pioneers as they explore the surface. Explore more on our YouTube channel—join NSN Today.
