A small, Apollo-class asteroid designated 2025 PU1 skimmed past Earth on August 13, 2025, at a distance of about 0.08 lunar distances from the planet’s center. The closest approach occurred at 19:44 UTC, with the object passing roughly 29,300 kilometers (18,200 miles) from Earth’s center.
PU1 is estimated to be only about 2 to 3 meters in diameter, placing it among the smaller near-Earth objects that have come within 1 lunar distance this year. Despite its tiny size, the flyby is part of a busy year for close approaches, ranking PU1 as the 10th closest asteroid flyby within the last 12 months and the 85th confirmed object to pass within 1 LD of Earth since the start of the year.
The asteroid was first observed later on August 13, at Piszkéstető Station in Hungary (GINOP‑KHK) at 23:55 UTC, about four hours after its closest approach. PU1 belongs to the Apollo group of asteroids, which cross Earth’s orbit and are among the most frequently observed near-Earth objects.
Looking ahead, PU1’s next anticipated approach to Earth is around April 3, 2036, at a distance of about 0.080 AU.
Why this matters: Even small asteroids like PU1 contribute to the growing dataset that helps scientists refine orbital models and improve detection capabilities for near-Earth objects. Close passes—especially those within a few tens of thousands of kilometers—offer valuable opportunities to test tracking methods and reduce uncertainties in future predictions. The ongoing monitoring of such objects is a testament to global efforts to map near-Earth space and keep the public informed with accurate risk assessments.
Key figures:
– Object: 2025 PU1
– Classification: Apollo-class asteroid
– Estimated diameter: 2–3 meters
– Closest approach: 0.08 lunar distances (about 29,300 km / 18,200 miles) from Earth
– Approach time: 19:44 UTC on August 13, 2025
– First observation: 23:55 UTC on August 13, 2025 (Piszkéstető, Hungary)
– Next predicted approach: April 3, 2036, at ~0.080 AU
Optional context for readers: The year 2025 has featured a high number of near-Earth object flybys within 1 LD, underscoring the importance of continuous sky surveys and rapid reporting. For the public, there is no threat associated with such small rocks at these distances; objects of this size typically burn up high in the atmosphere if they enter, and their observations help scientists keep Earth’s viewing of space accurate and up to date.
Summary: A tiny Apollo-class asteroid, 2025 PU1, passed Earth at about 0.08 lunar distances on August 13, 2025, with observations following a few hours after closest approach. It adds to a busy year for near-Earth object flybys and helps refine predictive models for future encounters, while offering a hopeful reminder of the robust monitoring systems in place to track space rocks that roam near our planet.