There’s an intriguing new discovery in our solar system: a rock known as 2025 PN7, recently labeled a “quasi-moon” by NASA.
Spotted by researchers this past summer, this object is not a true moon. Instead, it’s an asteroid that orbits the sun in sync with Earth. From our viewpoint, it looks like it’s circling our planet. Jacqueline McCleary, an observational cosmologist at Northeastern University, explains that while it seems to follow us, it’s not gravitationally bound to Earth like our actual moon.
2025 PN7 is part of the Arjuna asteroid group, which includes various near-Earth objects. McCleary notes that defining what exactly constitutes a moon is tricky. Astronomers often debate the criteria, with some leaning towards terms like “natural satellite.” This ambiguity means not every celestial companion fits neatly into a single category.
Interestingly, the quasi-moon has likely been a neighbor to Earth for about 60 years. However, it’s quite small—about the size of a small office building—making it hard to see without advanced telescopes. Jonathan Blazek, an astrophysicist from Northeastern, highlights that even with significant instruments, spotting such objects can be challenging.
Researchers used the Pan-STARRS telescope in Hawaii to find 2025 PN7. This telescope is particularly good at identifying new solar system objects and other dynamic phenomena, such as supernovae. Blazek is involved with the recently operational Rubin Observatory, which has even more potential for discovering new celestial bodies.
In fact, there are at least six other similar quasi-moons near Earth. These asteroids orbit in ways that keep them close to our planet while remaining relatively stable over time. For instance, 2024 PT5 was a temporary companion for several months last year.
Looking ahead, 2025 PN7 is expected to remain with us until about 2083 before drifting away into space. Despite its presence, experts assert that it will have little to no effect on Earth’s gravity or tides due to its small size—it’s vastly less massive than our moon.
This discovery sheds light on the fascinating dynamics of our solar system, emphasizing that our celestial neighborhood is more complex and varied than we often realize. As exploration continues, we might uncover even more unexpected companions circling our home planet.
For further details on the dynamics of near-Earth objects, you can refer to NASA’s extensive resources on planetary defense and asteroids here.
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Astronomy,Astrophysics,gravity,Jacqueline McCleary,moon,NASA
