High-resolution images captured by space probes confirmed that the natural satellite of Terra remains geologically active and in the process of reducing its diameter. The continuous cooling of the lunar core causes thermal contraction that forces the crust to adjust, resulting in cracks and deformations on the surface. Esse geological phenomenon generated a radial reduction of approximately 50 meters in the last 200 million years, altering the topography of the star.
Detailed analysis of the images allowed the identification of tectonic structures in areas that were previously considered stable by scientists. The mapping covered the lunar seas, vast plains of dark basalt formed by ancient volcanic eruptions, where newly formed ridges were located. The discovery changes the understanding of the distribution of global tectonic forces in Lua.
- The new faults indicate that crustal compression occurs widespread and not just in the highlands.
- The phenomenon is compared to the wrinkling of the skin of a fruit that dries out and loses internal volume.
- Historical seismic data from the Apollo missions corroborates the existence of active tremors associated with these faults.
This internal dynamic suggests that the celestial body is not an inert object, but rather an environment in constant transformation. The compression of the lunar lithosphere generates tensions that, when released, cause significant seismic shocks, known as “moonquakes”, which can last much longer than terrestrial earthquakes.
Mapping recent deformations
The researchers cataloged a total of 1,114 new ridges located specifically in the lunar maria, bringing the total number of known structures to 2,634. Essas formations, technically classified as “small mare ridges”, are estimated to be around 124 million years old, which is considered recent in terms of geological time. The dating close to the lobate scarps, which have an average of 105 million years, reinforces the theory of a single mechanism acting across the globe.
Dynamics of internal cooling
The physical process behind these topographic changes is the secular cooling of the interior of Lua. As heat from the core dissipates into space, the inner material contracts and loses volume, leaving the outer crust without sufficient support. Como the surface is rigid and inelastic, it breaks and overlaps in thrust faults to accommodate the decrease in surface area, creating the reliefs observed by orbital probes.
This contraction does not occur silently or subtly, but through rupture events that release accumulated energy. The existence of young, connected ridges suggests that compressive stress continues to shape the lunar landscape today. The correlation between visible faults and thermal loss confirms geophysical models that predict the evolution of small, rocky planetary bodies.
Distribution in lunar seas
The evidence collected shows that regions such as Mar, Tranquilidade and Mare Procellarum harbor clear signs of recent tectonic activity. Anteriormente, it was believed that most deformation was restricted to the highlands, the brightest and oldest areas of the surface.
The presence of faults in the Aitken basin, located at the south pole of the hidden side of Lua, demonstrates the global scale of the phenomenon. Basalt plains, formed by solidified lava, are being compressed and fractured in the same way as older land.
This new geographic distribution of faults forces planetary geologists to reconsider satellite seismic hazard maps. The activity is not confined to specific areas, but spread across different types of terrain.
Integration between geological structures
A crucial aspect revealed by the study is the direct physical connection between the newly identified ridges and the already known lobate scarps. Essas connections frequently occur in transition zones between the seas and highlands, functioning as a continuous system of faults.
The continuity of these structures across different geological domains proves that the driving force is global and uniform. The shrinking lunar beam simultaneously affects the basaltic crust of the seas and the anorthosite crust of the highlands, creating a complex network of interconnected fractures.
Implications for the artemis program
Recognizing these active faults is vital for planning future crewed missions, including the return of astronauts scheduled for this decade. NASA and other space agencies need to consider soil stability when selecting landing sites and building permanent bases.
Structures built close to active faults could suffer structural damage in the event of shallow earthquakes. The proximity of moonquake epicenters represents an operational risk that must be mitigated through accurate mapping.
The Artemis 2 mission, which will orbit Lua, will have the opportunity to visually validate some of these formations and collect new data. Direct observation will allow us to refine seismic hazard models and ensure the safety of crews on the ground.
Continuous monitoring of lunar geology has become a security requirement, not just a scientific curiosity. Entender where the crust is breaking helps avoid areas prone to regolith slides and terrain instability.
Seismic activity records
The seismographs installed during the Apollo missions, between 1969 and 1972, had already detected tremors that can now be correlated with these contraction faults. Reanalysis of this old data, combined with the new images, provides a more complete picture of lunar seismology.
Young ridges identified in the seas act as additional sources of seismic activity, complementing the highland escarpments. Isso indicates that the interior of Lua continues to adjust, and that the “silence” of space does not apply to the geology of our natural satellite.
Future of lunar research
Robotic and human exploration in the coming decades will be essential to install new networks of seismometers and obtain direct measurements of internal heat flow, deepening knowledge about the thermal evolution and geological life of Lua.