The space rock, known as 2020 BX12, is between 200 to 450 meters (656 to 1,476 feet) across and was traveling at about 90,000 kilometers (56,000 miles) per hour. According to experts, the asteroid was one of the most massive yet to pass by Earth in the last few weeks.
The Most Massive Asteroid to Pass in the Last Few Weeks
The asteroid skimmed by our planet at a distance of more than 4.3 million kilometers (2.7 million miles) on February 3rd. As it traveled, astronomers from Arecibo Observatory’s Planetary Radar Science Group in Puerto Rico captured it and noticed it was not alone. Apparently, 2020 BX12 has its own moon, which measured about 70 meters (230 feet).
“Preliminary analysis suggests that the primary asteroid is a round object at least 165 meters in diameter rotating approximately once every 2.8 hours or less,” they wrote in an announcement.
“The satellite has a diameter of approximately 70 meters and rotates once every 49 hours or less. The distance between the two bodies is at least 360 meters, as observed on February 5th. The movement of the satellite between the two observations, which were made ~23 hours apart, suggests a mutual orbital period of 45-50 hours and would be consistent with a tidally locked satellite.”
Asteroids With Moons
It is, in fact, not that odd for asteroids to have moons as there are a number of those kinds of space rocks in the main asteroid belt that are known to have their own moons, and about 60 near-Earth ones also have at least one moon.
However, due to the fact that asteroids are difficult to identify, information on the reason many of them have moons has not been acquired. Some space rocks have two moons, and sometimes, researchers find a binary asteroid where both of them have a similar diameter. Scientists do not know how asteroids get to have a moon of their own, either.
2020 BX12 is labeled as Apollo asteroid, a group that moves between Earth’s orbit and past Mars. It is allegedly scheduled to pass Mars in June 2020 and will also fly by Earth in 2022 and 2024 again, and it will travel at greater proximity than this year’s pass.