Asteroid 2025 UN flew past Earth at 0.45 LD on October 16, 2025

Asteroid 2025 UN, a near-Earth object, flew past Earth at a minimum distance of 0.45 lunar distances (LD) / 0.00115 astronomical units (AU), equivalent to approximately 172 000 km (107 500 miles), at 17:40 UTC on October 16, 2025. The flyby occurred with a relative velocity of 10.19 km/s.

Based on its absolute magnitude (H) of 28.782, asteroid 2025 UN is estimated to be about 7 to 16 m (23 to 52 feet) in diameter, though the actual size depends on its albedo.

Asteroid 2025 UN is classified as an Apollo-type near-Earth asteroid. Its orbit has an eccentricity of 0.36 and a semi-major axis of 1.31 AU, with a perihelion distance of 0.838 AU. The inclination of its orbit is 1.68°, which is typical for Apollo-group asteroids. The aphelion distance is 1.78 AU, and its orbital period is approximately 547 days.

Physically, asteroid 2025 UN is not classified as potentially hazardous (PHA) under current guidelines.

2025 UN was first observed on October 17, 2025, and last observed on October 18, 2025, resulting in a very short observation arc of just one to two days. The orbit solution has a condition code of 6, indicating its trajectory is uncertain or preliminary and may be refined with further observations.

Several other near-Earth asteroids have passed within 1 lunar distance of Earth recently. Asteroid 2025 TP5 made a close approach at 0.25 LD / 0.00065 AU (37 500 km / 23 300 miles) at 20:09 UTC on October 15, 2025, with a size estimate of 16 to 36 m (52 to 118 feet). Asteroid 2025 TN5 flew past at 0.35 LD / 0.00091 AU (52 000 km / 32 300 miles) at 04:18 UTC on October 10, 2025, with an estimated size of 11 to 24 m (36 to 79 feet). Asteroid 2025 TC approached at 0.22 LD / 0.00057 AU (32 300 km / 20 300 miles) at 06:34 UTC on October 3, 2025, with an estimated size of 14 to 30 m (46 to 98 feet).