- Astronomers discovered a small asteroid, 2025 PN7, orbiting near Earth
- The asteroid, first spotted by Hawaii’s Pan-STARRS observatory, has likely followed this path for about 60 years
- At magnitude 26, 2025 PN7 is far too dim to see without powerful telescopes and poses no danger to Earth
A faint asteroid discovered in August has joined Earth’s orbiting neighborhood, traveling alongside our planet and behaving like a second moon.
Earth has only one moon, which is about 239,000 miles away. But astronomers recently discovered asteroid 2025 PN7, known as a “quasi moon.”
The Pan-STARRS observatory in Hawaii first detected the object in August. It was later reported to the Minor Planet Center, which tracks and names new celestial bodies, and designated as 2025 PN7.
Asteroid 2025 PN7 is a faint, relatively small space rock — about 60 feet in diameter — that seems to circle Earth, according to EarthSky.
Scientists think it may be a fragment ejected from the moon. The object has likely followed this quasi-moon orbit for roughly 60 years and is expected to remain nearby for about another six decades before moving away.
Over time, asteroid 2025 PN7’s path changes. It shifts between what scientists call a “horseshoe orbit” and its current “quasi-moon” state — and it will eventually switch back again.
A horseshoe orbit is still an orbit around the sun, but from Earth’s viewpoint, it looks like the asteroid is tracing a horseshoe shape in the sky. That means 2025 PN7 will seem to approach Earth from behind, slow down, turn around, and then move ahead of us before repeating the cycle.
Does Earth have two moons?
Quasi moons behave somewhat like Earth’s moon because they appear to orbit our planet, but they’re actually asteroids that circle the sun along a similar path, according to The Planetary Society.
The newly discovered asteroid is one of seven confirmed quasi moons, according to the Planetary Society.
How to see Asteroid 2025 PN7
The asteroid has an official brightness rating of magnitude 26, which means it can only be seen with powerful telescopes. By comparison, most stars visible to the naked eye are magnitude 6 or brighter, while Sirius, one of the brightest stars, has a magnitude of about -1.5.
Asteroid 2025 PN7 is too small to see to the naked eye but may be spotted using specialized equipment found in observatories.
There are several in Michigan including:
- University of Michigan’s Detroit Observatory in Ann Arbor
- MSU Observatory in Lansing
- Calvin College Observatory in Grand Rapids
- Sherzer Observatory in Ypsilanti
- Joseph H. Rodger Observatory in Traverse City
- Baldwin- Wallace Observatory in Grand Rapids
- Fox Park Public Observatory in Potterville
- James C. Veen Observatory in Lowell
There are also several astronomy clubs across the state.
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