Now that it’s over, we can say that a big asteroid just went by Earth.
The 2023 BU space rock, which was about the size of a minibus, flew over the southern tip of South America just before 0:30 GMT.
With a distance of 3,600 km (2,200 miles) between them, it’s pretty close.
And it shows that there are still big asteroids hiding close to Earth that haven’t been found yet.
This one wasn’t found until last weekend by Gennadiy Borisov, an amateur astronomer who works from Nauchnyi in Crimea, which Russia took from Ukraine in 2014.
Follow-up observations have helped us get a better idea of how big 2023 BU is and, more importantly, how it moves.
So, astronomers were sure it wouldn’t hit Earth, even though it passed through the area where the world’s communications satellites, which are 36,000 km (22,000 miles) above us, are located.
There is a very, very small chance that you will hit a satellite.
The time of lowest altitude was found to be Thursday at 19:27 EST, which is Friday at 00:27 GMT.
Even if 2023 BU had been headed straight for 2023 BU, it wouldn’t have done much damage.
The rock, which was probably between 3.5m and 8.5m (11.5ft and 28ft) wide, probably broke up high in the air. Still, it would have made a beautiful fireball.
The famous Chelyabinsk meteor that hit the Earth’s atmosphere over southern Russia in 2013 was about 20 metres (66 feet) wide. It sent a shockwave through the ground that broke windows.
NASA scientists say that 2023 BU’s path around the Sun has changed because of its encounter with Earth.
The gravity of our planet pulled on it, which changed its path through space.
“Before hitting Earth, the asteroid’s orbit around the Sun was roughly circular, similar to Earth’s orbit, and it took 359 days to complete its orbit around the Sun,” the agency said in a statement.
“After the collision, the asteroid’s orbit will get longer, and at its farthest point from the Sun, it will be about halfway between Earth and Mars. Then, every 425 days, the asteroid will go around the sun once.
A lot of work is being done to find the much bigger asteroids that could really hurt the Earth if they hit it.
The real monsters out there, like the 12 km-wide rock that killed the dinosaurs, have probably all been found, so you don’t need to worry about them. But when it comes to something 150m wide, for example, there are gaps in our inventory.
Statistics show that maybe only about 40% of these asteroids have been seen and looked at to see how dangerous they might be.
If these things hit the ground, they would cause damage on the scale of a city.
Prof. Don Pollacco from the University of Warwick in the UK told BBC News, “There are still asteroids that cross Earth’s orbit that haven’t been found yet.”
“2023 BU is a recently found object that is about the size of a small bus and must have been close to Earth thousands of times in the past. This time, it will be only 2,200 miles from Earth, which is only 1% of the distance to the moon. This is a close call in space.
“Depending on what 2023 BU is made of, it is unlikely that it will ever reach the surface of the Earth. Instead, it will probably burn up in the atmosphere as a fireball brighter than a full moon.
“However, there are probably a lot of asteroids out there that haven’t been found yet that could get through the atmosphere and hit the ground, causing a lot of damage. In fact, many scientists think something like this could happen soon.”
