On January 3rd, 2025, the Near-Earth Asteroid (NEA) 2025 AB made a relatively close approach to Earth, passing within 153,000 kilometers – less than half the distance to the Moon. This roughly bus-sized asteroid, while not uncommon, provided a valuable opportunity for scientific observation and research due to its proximity.
NEAs, including 2025 AB, are classified as Near-Earth Objects (NEOs). These objects orbit the Sun within 1.3 astronomical units (AU) of Earth, approximately 45 million kilometers. NEAs are categorized into four groups: Atira, Aten, Apollo, and Amor. Asteroid 2025 AB belongs to the Aten group, named after the asteroid 2062 Aten, discovered in 1976. As of 2024, over 2,000 Aten asteroids have been identified, with a notable subset classified as potentially hazardous. Aten asteroids are defined by a semi-major axis (average distance from the Sun) of less than 1.0 AU and an aphelion (farthest point from the Sun) exceeding 0.983 AU.
Commenting on the nature of asteroids, Jay Tate, director of the UK’s Spaceguard Center observatory, explained to Newsweek that they are essentially “bits of a planet that didn’t happen,” orbiting the Sun primarily within the Main Asteroid Belt between Mars and Jupiter. Their relatively small size makes them susceptible to orbital disturbances, leading to trajectories that can intersect planetary orbits. Franck Marchis, a senior planetary astronomer at the SETI Institute, further elaborated, suggesting that these asteroids likely originated in the asteroid belt, being ejected by impacts or having their orbits destabilized by Jupiter’s gravitational influence.
Asteroids exhibit a wide range of sizes, from massive bodies exceeding 329 miles in diameter to smaller ones as small as 30 feet. While close approaches like that of 2025 AB are noteworthy, the probability of a collision with Earth remains exceptionally low.