Astronomers discover Earth’s hidden quasi-moon from the 1960s

A quasi-moon named 2025 PN7 has captured the attention of astronomers and scientists following its discovery on August 2, 2025. This near-Earth asteroid, measuring between 15 to 30 meters in diameter, is notable for its unique orbit. Although it appears to be in orbit around Earth, it is, in fact, following a stable path around the Sun, categorized under 'quasi-moons.' What is particularly fascinating about 2025 PN7 is its undetected presence for over 60 years, suggesting that it has been orbiting the Earth since the 1960s. Researchers found evidence of its presence in archival images dating back to 2014, confirming its consistent orbit spanning several decades. 2025 PN7 is situated in the constellation Piscis Austrinus (the “Southern Fish”), a region that is most visible from the Southern Hemisphere. This object's trajectory allows it to fluctuate between distances of 2.8 million miles to 37.2 million miles from Earth. It is capable of maintaining its orbit for another 60 years and poses no threat to our planet, offering a glimpse into the stable dynamics of celestial bodies in our solar system. Interestingly, 2025 PN7 is one of approximately seven quasi-satellites known to orbit Earth, alongside the well-known Kamoʻoalewa, which was discovered in 2016. Unlike mini-moons, which are temporarily captured by Earth's gravity, 2025 PN7's orbit reflects a 1-to-1 resonance with Earth, meaning it appears to follow the planet while still being fundamentally an independent object that orbits the Sun. The discovery ignites curiosity regarding future exploration of such celestial bodies. Currently, there are discussions around sending spacecraft for closer inspection, similar to the plans for China’s Tianwen 2 mission to Kamoʻoalewa, which expects to reach its destination in July 2026. As our understanding of quasi-moons expands, questions arise about their formation, stability, and the potential for future study to provide insights into our solar neighborhood and the mechanics of celestial motions.