Based on assumptions about how much light is reflected, 2026JH2 is currently estimated to be between 15 and 30 meters (49 and 98 feet) in diameter. At the smaller end of that range, Michel said, it would be similar in size to a bolide, or fireball, that exploded in the atmosphere over the city of Chelyabinsk, Russia, in 2013, shattering windows and injuring 1,000 people. At the highest end of the range, it would be closer in size to an object that exploded near the Podkamennaya Tunguska River in Siberia in 1908, which pulverized large swaths of forest.

I find it amazing that doubling a small object’s size seems to a produce a non-linear increase in impact effect. The majority of the earth’s surface is water or sparsely inhabited, but something just 30 meters across has the effect of a low nuclear yield. A week’s worth of notice on one of these striking near a large city would be pretty chaotic.

With all the private space exploration gaining traction, it surprises me that there’s not more dedicated to detecting objects that intersect our trajectory.