The data from the National Aeronautics Space Administration's (NASA) Lunar Reconnaissance Orbiter (LRO) shows ridges with freshly exposed bedrock on the moon's surface. It is believed that the moon's active tectonic system might have caused these ridges.
On the near side of the moon, about 500 patches of exposed rock are found that formed during the 14 days of darkness. Patches like these are usually quickly covered, suggesting that they just happened recently. Upward motion is breaking the surface and exposing the rocks, allowing regolith to drain into cracks and voids, exposing the rocks.
The moon has an active tectonic system
The moon's bedrock ridges are possibly caused by the echo of a long-ago impact that nearly tore it apart around 4.3 billion years ago. Most of the moon's surface comprises of regolith, which is a powdery blanket of ground-up rock formed by the constant bombardment of tiny meteorites and other impactors. Those areas without regolith where bedrock is exposed are considered rare.
The team of experts from the Brown University used the LRO to look for strange spots within and surrounding the large dark patches on the surface of the moon, called the lunar maria.
The co-author of the research Professor Peter Schultz of Brown university's Department of Earth, Environmental and Planetary Sciences said that since regolith buildup happens regularly, exposed blocks on the surface have a relatively short lifetime. So, seeing those poses questions as to how and why they were exposed to specific locations.
Using the nighttime observations from LRO's Diviner instrument, Schultz and the study's lead author, Adomas Valantinas, a graduate student at the University of Bern, uncovered more than 500 patches of exposed bedrock.
Exposed ridges are not new to the moon's surface, but those ridges in the past were on the edges of ancient lava-filled impact basins and were formed because of sagging from the weight caused by the lava.
However, the latest discovery of the new ridges is determined to be related to an active tectonic system. After mapping all the exposures revealed in the Diviner data, the team found an interesting correlation.
Active Nearside Tectonic System (ANTS)
Way back in 2014, the GRAIL mission of NASA discovered a series of ancient cracks in the moon's crust. It is believed that magma once flowed from them. The researchers showed that the blocky ridges seemed to line up just about perfectly with the deep intrusions as revealed by GRAIL.
According to Schultz, it is an almost one-to-one correlation that makes the scientists think that the ridges seen on the moon's surface are undergoing a process driven by things happening in the moon's interior. They suggest that until now, the ridges are continuing to heave upward.
Its upward movement leaves the blocks exposed as the surface breaks and enables regolith to drain into cracks and voids. The scientists called their discovery the Active Nearside Tectonic System (ANTS), and they believe that it was sparked by a massive impact on the moon's farside billions of years ago.
