Asteroid 2026JH2 Safely Passes Earth Today

An asteroid identified as 2026JH2, estimated to be between one and two school buses in size, is set to make a close pass by Earth on Monday. The celestial object will approach within 91,593 kilometers (56,913 miles) of our planet, a distance equivalent to about one-quarter of the span between the Earth and the moon. Astronomers at the Mount Lemmon Survey in Tucson, Arizona, first detected the asteroid on May 10, 2026, and subsequently designated it 2026JH2. This space rock is classified as an Apollo asteroid, a group characterized by orbits that intersect with Earth's path around the sun. The closest approach is scheduled for Monday just before 6 p.m. ET, according to NASA’s Jet Propulsion Laboratory Small-Body Database. Despite its proximity, experts assure that the asteroid poses no threat to Earth.

Richard Binzel, a professor of planetary sciences at the Massachusetts Institute of Technology and the creator of the Torino Scale, a system for assessing potential asteroid impacts, confirmed the safety of the encounter. "2026JH2 will pass safely by the Earth," Binzel stated via email. "This is actually a rather normal occurrence, car-sized objects pass between the Earth and the Moon every week. At the size of a school bus, these pass through our neighborhood several times per year. We are only recently developing surveys that are sensitive enough to see them," he added. Binzel noted that without these advanced surveys, objects of this size would typically pass unnoticed.

Understanding Asteroid Origins and Size Uncertainty

The asteroid originates from the main asteroid belt, a region located between Mars and Jupiter. "Occasional collisions in the asteroid belt, plus gravitational tugs by Jupiter, can send small asteroids into Earth’s vicinity. This fact has been known for many decades and many thousands of asteroids that can pass near the Earth are already known," Binzel explained. However, determining the precise size of 2026JH2 remains challenging. When astronomers first observe a new object with optical telescopes, they primarily gauge its luminosity. The amount of light an object absorbs or reflects is not immediately clear, according to Patrick Michel, an astrophysicist and director of research at the National Centre for Scientific Research in France. "Thus, at the same luminosity, an object can be bigger and darker, or smaller and more reflective," Michel said in an email. "To know the size, we would need observations in the infrared, because the luminosity in the infrared is directly proportional to the size. But such observations are more difficult to do from the Earth and are not used to discover new objects."

Based on assumptions regarding reflectivity, 2026JH2 is currently estimated to have a diameter between 15 and 30 meters (approximately 49 to 98 feet). At the lower end of this estimate, Michel noted, the asteroid would be comparable in size to the bolide that exploded over Chelyabinsk, Russia, in 2013, injuring over 1,000 people. At the upper end, its size would approach that of the object responsible for the 1908 Tunguska event in Siberia, which devastated vast forested areas. Unlike these historical events, 2026JH2 is not expected to enter Earth's atmosphere, thus posing no risk of atmospheric explosion or ground impact.

Michel emphasized that while the asteroid's flyby distance might seem close, it is "far enough that there is absolutely nothing to worry about." However, predicting the long-term trajectory of such objects can be complex, and the possibility of future collision courses, while unlikely for this specific object, cannot be entirely ruled out. "The good news is that so far, no asteroid that we know of poses a risk for the timescale of our predictions, which is about a century on average," he added.

The upcoming close approach of asteroid Apophis, projected for April 13, 2029, at a distance of 32,000 kilometers (19,883 miles), is significantly larger than 2026JH2. "Yet, we are not worried at all, and on the contrary very excited," Michel commented. "Such a close approach of such a big object occurs only once in a few thousands of years and its light will even be visible with the naked eye in the night sky across Europe, Africa and part of the middle East." In contrast, 2026JH2 will only be visible through small telescopes under dark sky conditions and will be far too faint to be seen with the naked eye. Jean-Luc Margot, a professor of Earth, planetary and space sciences at the University of California, Los Angeles, explained that limited detailed information is partly due to the current degradation of planetary radar capabilities. "The Arecibo telescope collapsed in 2020 and NASA’s Goldstone antenna is down for major repairs for an extended period of time. Without radar data, we are less capable of assessing the impact risk and we are more vulnerable to the impact hazard."

The Virtual Telescope Project is scheduled to provide a partial livestream of the close pass, beginning at 3:45 p.m. ET. As of now, astronomers have cataloged only about 1% of near-Earth asteroids comparable in size to 2026JH2. "It’s not surprising that this object was discovered only a few days before its closest approach to Earth, when it became bright enough to be picked up by asteroid detection surveys," Margot noted. He also highlighted concerns about the incomplete knowledge of near-Earth object populations but pointed to current efforts by space agencies to fund more discovery surveys and improve the inventory of potentially hazardous asteroids.