Astronomers have identified a previously unknown celestial object, designated 2025 PN7, which follows an Earth-like orbit around the Sun and remains in relative proximity to our planet.
The discovery, detailed in the journal "Research Notes of the American Astronomical Society," highlights the dynamic cosmic environment around Earth. 2025 PN7 was first detected by the Pan-STARRS observatory in Hawaii on August 2, 2025. Analysis of archival data suggests the object has been in a stable, Earth-like orbit for several decades, sekitar 60 tahun.
Carlos de la Fuente Marcos, a researcher from the Complutense University of Madrid and lead author of the study, explained that 2025 PN7 is only detectable by current telescopes when it approaches Earth, as it did this past summer. Unlike temporary mini-moons that orbit Earth for short periods, objects like 2025 PN7 are classified as quasi-moons. These are essentially asteroids that remain near Earth due to orbital resonance, even though they technically orbit the Sun.
2025 PN7 is among the smallest known quasi-moons near Earth, with an estimated diameter of sekitar 19 meter. It has an absolute magnitude of 26.4, making it visible only through large research telescopes. Scientists predict its current orbit will remain stable for sekitar 128 tahun before the Sun's gravitational pull shifts it into a more distant orbit. The Yarkovsky effect, a thermal force from uneven heat emission, may also gradually alter its orbit over time, contributing to its instability.
Carlos de la Fuente Marcos described 2025 PN7 as "the smallest and most unstable Earth quasi-satellite known." While its exact composition is unknown, scientists believe it is likely a rocky, natural object. This discovery contributes to our understanding of near-Earth objects and complex orbital dynamics. The Pan-STARRS observatory, a leading telescope for discovering near-Earth objects, continues to play a crucial role in identifying celestial bodies like 2025 PN7, paving the way for deeper exploration and comprehension of our cosmic surroundings.
2025 PN7 is the smallest and least stable of Earth's known quasi-moons, with a diameter of about 19 meters (62 feet). It was first reported by French astronom amatir Adrien Coffinet on August 30, 2025, who noted its potential as a quasi-satellite untuk 60 tahun ke depan. The asteroid's faintness and limited visibility windows have made it difficult to detect until now.
Quasi-moons are distinct from mini-moons, which are temporarily captured by Earth's gravity. 2025 PN7, like other quasi-moons such as Kamo'oalewa, orbits the Sun but appears to stay close to Earth. Kamo'oalewa is a target for China's Tianwen-2 mission, which aims to collect and return samples in 2027.