A Small Asteroid Surprised NASA When It Passed Very Close To The Planet

NASA usually keeps an eye on every asteroid in space that has the potential to impact the Earth. It routinely says that most of these asteroids are small and pose no risk, but there's always some fear that a large and unknown asteroid could be lurking in space. Recently, a small asteroid roughly the size of a refrigerator came extremely close to the Earth.

It's not the size of the asteroid that worries scientists so much. Rather it was that the asteroid came from the direction of the sun, and scientists didn't even know it was there. The asteroid is called Asteroid 2021 UA1 and is the third closest approach by an asteroid ever. A distance of 3000 kilometers is extremely close, but the asteroid's small size meant it posed no risk.

Astronomers say the asteroid approached the planet passing over Antarctica last Sunday. While 3000 kilometers sounds very close, that puts it outside the orbit of the ISS. Despite being outside the orbit of the ISS, it was lower than the orbit of communications satellites. With a diameter of roughly 2 meters, had the asteroid entered the planet's atmosphere, it would have burned up before hitting the ground.

Astronomer Tony Dunn says the flyby was so surprising because it came from behind the sun coming from the daytime sky. Approaching in that manner made the asteroid invisible until its close approach. The only asteroids to have ever come closer to the Earth included 2020 QG, which came within 1830 miles of the planet. Asteroid 2020 VT4 passed by at a distance of only a few hundred miles away from the planet. All of those asteroids were too small to have caused harm to the planet.