Amazing, I admit. Despite years of stargazing, tracking planets, and scanning deep-sky objects with telescopes, it wasn’t until about five years ago that I became acutely aware of the existence of the Moon Man. As I studied the familiar dark plains and bright highlands, I somehow overlooked a pattern that people have recognized for thousands of years.
The moon has endured constant bombardment over its 4.5 billion year history. The large dark region that forms Moon Man’s “ocean” is actually a vast impact basin created during a period of violent collisions that ended about 3.8 billion years ago. Although such large-scale impacts are no longer common, smaller asteroids and comets still hit the moon, leaving new craters.
How scientists discovered a new lunar crater
It is very difficult to capture these effects on the fly. Instead, scientists look for evidence after the fact. The Lunar Reconnaissance Orbiter camera team discovered the new crater by carefully comparing images of the same area taken at different times. By identifying changes between photos taken before December 2009 and photos taken after December 2012, researchers were able to narrow down when the crash occurred, even though no one actually saw it happen.
The newly identified crater is about 22 meters wide, roughly the size of a large house. What stands out is not its size, but its brightness. The impact threw material outward for tens of meters, forming a shocking beam of light that spread out in a sunburst pattern. This newly exposed material is much brighter than the dark surrounding regolith, making the crater look like a new mark on a familiar surface.
Why bright craters disappear over time
That brightness doesn’t last. Space weathering, caused by solar wind particles, micrometeorite impacts, and cosmic radiation, gradually darkens exposed material. Over thousands to millions of years, the crater’s rays fade until they blend with the older terrain. This process explains why younger craters like Tycho, which formed about 108 million years ago, still show prominent streaks visible from Earth, while ancient craters lack bright rays.
Finding new craters is more than just an interesting discovery. This helps scientists better estimate how often collisions occur. This is important for assessing risks to spacecraft and future manned missions. Studying how craters and their features change over time can also help researchers refine the methods used to determine the age of various lunar surfaces.
the moon is still changing
For those who enjoy observing the moon, there’s something surprising about learning that it’s not a stationary object. The surfaces we have observed over generations continue to evolve, acquiring new features as we move through space. These fresh craters are a reminder that the moon continues to be shaped by ongoing collisions, and that the solar system is still active and sometimes violent.
