The planet, designated 2023 BU, approached the southern tip of South America on Friday about an hour and a half after midnight CET. It flew about 3,600 kilometers above the surface, which is a smaller distance from Earth than the satellite orbits in a so-called geosynchronous orbit. At an altitude of 35,786 kilometers, about a third of all satellites orbit the Earth. For comparison: the International Space Station (ISS) is at an altitude of 408 kilometers from Earth, so the asteroid was only about nine times farther from our planet than this station.
The planet was discovered only on Saturday by amateur astronomer Gennady Borisov from his observatory on the Crimean peninsula. In 2019, the same scientist was the first to spot a comet that entered the Solar System from another system. Observations of the planet then began to be reported by scientists around the world – and thanks to further measurements, they helped to better determine its trajectory.
NASA Impact Risk Assessment System, which is called Scout, quickly ruled out that asteroid 2023 BU could hit Earth. “But despite very few observations, he was able to predict that the asteroid would come extremely close to Earth,” said Davide Farnocchia of the Jet Propulsion Laboratory (JPL), which developed the Scout system. “In fact, this is one of the closest recorded approaches of a known body,” the scientist added. On Thursday, this was confirmed on Twitter by the director of NASA, who at the same time reassured the public that it was nothing dangerous:
According to experts, there was no risk of a collision with Earth during the approach. Assuming that the asteroid had an estimated size of around eight meters, it would not have hit the surface of our planet as a whole, but would have disintegrated about 30 kilometers above the ground. Impacts of objects with a diameter of eight meters occur on average every five years, and impacts of objects with a diameter of four meters occur on average every year. But what didn’t happen this year could happen in the future – according to NASA, this asteroid has a 1 in 10,000 chance of hitting Earth between 2077 and 2123.
After passing by the Earth, the planet’s trajectory will change dramatically due to the influence of the Earth’s gravity. Instead of orbiting the Sun every 359 days, it will move into an oval orbit lasting 425 days, according to NASA.
Around the Earth, scientists have identified around 27,000 asteroids, of which about 10,000 are more than 140 meters in diameter, writes the DPA agency. None of them are expected to hit our planet anytime soon. NASA tested Earth’s defenses against a space body for the first time last year when it sent a probe to the asteroid’s moon Didymos. That object, which posed no danger to Earth, struck and successfully deflected it off course.
