https://explorersweb.com/new-quasi-moon-discovered-orbiting-earth-but-its-been-around-for-decades/ * [p] ExplorersWeb Logo ExplorersWeb Logo ExplorersWeb Logo Search Icon Facebook Icon E-mail Icon Menu Icon * Home * Breaking News * Expeditions + Mountaineering + Polar Exploration + Long-distance Trekking + Canoeing & Kayaking + Ocean Rowing + Misc Sports * Science + Archaeology + Geography + Polar Research + Oceanography + Space + Weather + Wildlife + Medical + Climate change * Gear + Buyers Guides + Reviews Search Icon Facebook Icon E-mail Icon Login Icon [ ] Go New Quasi-Moon Discovered Orbiting Earth, But It's Been Around For Decades September 25, 2025 Rebecca McPhee Space schematic of the quasi-moon's orbit The orbit of 2025 PN7. Image: NASA Astronomers have found a space rock that has been quietly hanging around Earth for decades: a tiny asteroid named 2025 PN7. This so-called "quasi-moon" isn't a true moon or a mini-moon, because it orbits the Sun rather than our planet. But its orbit is so similar to Earth's that it will be our companion for around another 60 years. Though the quasi-moon orbits the Sun, it occasionally looks from our vantage point like it is looping around us. However, our orbits are slightly different, so sometimes it lags behind us and sometimes it seems to lead us. But since the little asteroid's orbit around the Sun is very close to one Earth year, it is always pretty close. 2025 PN7 is just 19 meters across and might be the smallest quasi-moon ever found. Its minuscule size means that it can be quite tricky to spot. As astronomers put it, its "visibility windows" are very narrow. We can only see it through very large telescopes when its position and the lighting are favorable. That's partly why it evaded detection for so long. Entered orbit in 1957 Although the Pan-STARRS1 telescope in Hawaii discovered it in August 2025, the quasi-moon has been in this orbit for far longer. When researchers later trawled through archived images, they found that 2025 PN7 had shown up decades earlier. They think it likely entered its current orbit in 1957. It won't stay with us in this dance forever. Simulations suggest that it will keep up company for another 60 years before it wanders off in another direction. In that time, its distance from Earth will change quite a bit. So far, it has varied between 4 million kilometers at its closest and 18 million kilometers at its furthest. 2025 PN7 is one of seven quasi-moons in Earth-like orbits, and seems to be the smallest and least stable. Astronomers aren't exactly sure where it came from. It does not pose any threat to us. "These asteroids are relatively easy to access for unmanned missions and can be used to test planetary exploration technologies [relatively cheaply]," said Carlos de la Fuente Marcos, lead author of the study. [IMG_0241-300x300] Rebecca McPhee Rebecca McPhee is a freelance writer for ExplorersWeb. Rebecca has been writing about open water sports, adventure travel, and marine science for three years. Prior to that, Rebecca worked as an Editorial Assistant at Taylor and Francis, and a Wildlife Officer for ORCA. Based in the UK Rebecca is a science teacher and volunteers for a number of marine charities. She enjoys open water swimming, hiking, diving, and traveling. Also on Explorersweb A model of the solar system in the desert Weekend Warm-Up: The Solar System to Scale Conventional images of the Earth and the moon place... September 20, 2025 Lou Bodenhemier A bright blue dot among smaller blue flashes Is the 3I/ATLAS Comet Actually Alien Technology? No. Named 3I/ATLAS, this comet is the third-ever interstellar visitor... September 14, 2025 Lou Bodenhemier dark Pacific Ocean, with clouds above Point Nemo, Pole of Isolation and Future ISS Graveyard Where is the true "middle of nowhere?" Philosophically speaking,... September 14, 2025 Lou Bodenhemier [Screenshot-2025-09-09-at-00] NASA Offers Inventors $155,000 to Reinvent the Lunar Wheel The Rock and Roll with NASA competition offers up... September 11, 2025 Rebecca McPhee The International Space Station, seen from an orbiting spacecraft. Spending Time in Space Can Speed Up Aging Space is packed with hazards and health risks, and... September 9, 2025 Lou Bodenhemier An artist's drawing of the debris from ancient impacts scattered through Mars' mantle. Mysterious Blobs Beneath Mars' Surface Beneath the surface of Mars lie an array of... September 8, 2025 Rebecca McPhee Sign up for ExplorersWeb Emails [ ] Subscribe Popular Posts Tyler Andrews' Everest FKT Attempt Begins in 24 Hours September 22, 2025 Angela Benavides Tyler Andrews Launches Everest FKT Early, Turns Around at 7,400m September 23, 2025 Angela Benavides Sieberer and Messner Bail on Chumik Kangri Just Days Before Its First Ascent September 23, 2025 Angela Benavides 50 Years Ago: The First Ascent of Everest's Southwest Face September 24, 2025 Kris Annapurna ExplorersWeb is part of AllGear Digital's portfolio of media brands. * About Us * Privacy Policy Explorersweb (c) 2025 Quantcast x Sign up for ExplorersWeb Emails Sign up to receive ExplorersWeb content direct to your inbox once a week. Email Address * [ ] [ ] [Subscribe] By signing up for email newsletters, you agree to ExplorerWeb's Privacy Policy.