Guys, I know it sounds crazy, but our Moon may have a lot of smaller “cousins” floating around. I kid you not: It looks like the space near Earth is full of tiny satellites that no one has noticed before. Scientists recently identified a second piece of the Moon wandering around, and it has them going nuts with excitement. “If there are two of them, we’re pretty sure they’re a population,” he says. Teddy Bear ofLowell Observatory. In short, minimoons could be all around us, hiding in plain sight. And to think that we thought we knew our little corner of the cosmos well.
Lunar Fragments in Orbit
The Earth travels through (and with) a cloud of debris as it circles the sun. Some of this material is man-made: satellites e space debris. The rest are rocky fragments left over from collisions that occurred early in the solar system. These near-Earth objects are being tracked to ensure they do not pose a threat to our planet.
In August 2024, astronomers in South Africa have identified a new rock, called 2024 PT5, which was traveling close to Earth. This rock was moving slowly, with a relative speed of only 7,2 km/h, making it an interesting target for the Mission Accessible Near-Earth Object Survey (MANOS). Only nine other asteroids have ever been seen traveling this slowly at their closest approach.
Kareta, together with the principal investigator of MANOS Nick Moscowitz, also of theLowell Observatory, were intrigued by the idea of finding moon rocks in space shortly after the first such fragment was identified in 2021. Within a week of discovering 2024 PT5, they had already pointed the Lowell Discovery Telescope in the direction of this space rock.
Close Encounters of a Different Kind
After studying 2024 PT5 with both visible and near-infrared data, researchers concluded that it was no ordinary asteroid. Its composition was similar to rocks returned to Earth during the Apollo program, as well as those returned by the Soviet Union's Luna 24 mission. Researchers also found that 2024 PT5 was small, with a diameter of 8 to 12 meters.
In their just published study, Kareta and his colleagues suspect that 2024 PT5 was hurled into space when something slammed into the Moon. By studying the asteroid's composition, they hope to connect the material to its source and perhaps even identify the crater of origin.
It's like realizing that a crime scene has a whole new type of evidence that you didn't know you had before.
Cratering events are one of the most important processes that shape planetary bodies without tectonics or liquids. But impacts can be influenced by a variety of variables, and understanding them can be a challenge. Matching debris to its crater may provide another way to understand what happens when two bodies collide. That's why identifying moon rocks in space is so intriguing.
Mini Moon, the strange “lane change”
Material from the Earth-Moon system should be among the easiest to fall into near-Earth orbit. After an impactor collides with the Moon, all but the fastest-moving material flung into space should continue to travel near our system. Although 2024 PT5 was dubbed a minimoon last September, It remained in line with the planet for only a short time.
Kareta compared it to two cars on the highway. Earth hurtles along in its lane, while 2024 PT5 proceeds along the inner path, closer to the sun. In 2024, this tiny piece of rock changed lanes, falling into Earth's path at about the same rate. By the end of September, it had moved outward. Earth left it behind, but on the solar "race track," The two should be parallel again by 2055, scientists estimate.
2024 PT5 is the second lunar fragment identified by researchers. Another little rock, Kamo'oalewa, was brought back to the Moon in 2021, five years after its discovery. This suggests a new population of minimoons hiding in plain sight.
I can't wait to find out, perhaps thanks to new generation observatories like Vera Rubin, how many other “pieces of the Moon” will we find in space in the coming years. It makes me smile to think that we have always looked at the Moon as the only celestial companion, when in reality we could have dozens of mini moons that revolve around us without us noticing.
It’s like discovering you have an extended family when you thought you were an only child. And I wonder: what will these fragments tell us about the “violent history” of our satellite? The night sky is much more crowded and interesting than ever.
