2025 PN7 is a “quasi-moon” that appears to have been in orbit of Earth since the 1960s without being noticed — until now. (Generic image)
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Say hello to 2025 PN7, a “quasi-moon” that appears to have been in orbit since the 1960s without being noticed. First spotted on Aug. 2, 2025, the new object has since been seen in archive images from telescopes that suggest that it’s been in orbit for 60 years — and will likely remain in orbit for another 60 years. It poses no threat to Earth.
What And Where Is 2025 PN7?
2025 PN7 is a near-Earth asteroid and is 15-30 meters in diameter — about a third of the height of the Statue of Liberty. Known as an Arjuna asteroid, scientists last week revealed its existence in a study published in Research Notes of the American Astronomical Society. According to Sky & Telescope, researchers found archival images extending back to 2014, with orbital models suggesting it has been in a stable orbit since the 1960s — and will remain there for another 60 years.
2025 PN7 is currently in the constellation Piscis Austrinus (the “Southern Fish”), which is best seen from the Southern Hemisphere. It’s orbiting between 2.8 million miles and 37.2 million miles from Earth
What Is A ‘Quasi-Moon?’
Earth has only one permanent natural satellite. However, astronomers have discovered several small bodies that appear to orbit Earth even though they actually orbit the sun. These are known as quasi-moons or quasi-satellites, and their orbital resonance makes them look like companions to our planet. 2025 PN7 is such an object, moving in sync with Earth in a 1-to-1 resonance, creating the illusion of orbiting Earth while actually orbiting the sun.
What Is A ‘Mini Moon?’
Mini-moons are different, being asteroids temporarily captured by Earth’s gravity. An asteroid called 2024 PT5 orbited Earth for just 57 days in 2024 before slipping back into its solar orbit. Mini-moons are captured objects that orbit for just a few weeks while quasi-moons like 2025 PN7 can remain in orbit for decades.
2025 PN7 Vs. Kamoʻoalewa
2025 PN7 is one of about seven quasi-satellites orbiting Earth. The most famous is Kamoʻoalewa, also called 2016 HO3, discovered in 2016. At about 130–330 feet (40-100 meters) in diameter — roughly the size of the Statue of Liberty — it is significantly larger than 2025 PN7. Its name, drawn from Hawaiian, means “oscillating celestial object,” reflecting its looping orbit that always keeps it near Earth.
Should We Send A Spacecraft To Study 2025 PN7?
China’s Tianwen 2 is expected to reach Kamo’oalewa in July 2026 to spend a few months in orbit taking measurements, before taking a sample to send back to Earth in a capsule in 2027. Kamoʻoalewa will be the smallest asteroid ever visited.
Could a spacecraft one day visit 2025 PN7? “Objects in this unusually stable orbit are often unusually easy to visit with spacecraft, already coming quite close to Earth at a lower speed than most,” Sam Deen, an amateur astronomer, told Sky & Telescope. “So lower-budget future missions should have a relatively easy time getting to these for exploration, sample return, or even outright asteroid mining.”
Wishing you clear skies and wide eyes.
