2023BU: Earth is about to get one of its closest ever asteroid encounters
Asteroid 2023 BU: Earth is about to get one of its closest ever asteroid encounters
Image source, JUAN GARTNERImage caption, It's going to get very close to us, but we're not in any dangerWe're about to get closer to an asteroid than ever before!This is because a big piece of space-rock called Asteroid 2023 BU will be making its journey right past Earth - so close that it might even get lower than some communication satellites.It's due to zoom past the very Southern tip of South America 7.27pm US eastern time on Thursday 26 January (that's 12.27am GMT in the UK on Friday 27 January).When it gets there, it'll only be 3,600 kilometres (2,200 miles) above the planet's surface.More stories that are out of this world!Is the asteroid dangerous?Image source, NASA/JPL-CaltechImage caption, This diagram from Nasa shows the journey the asteroid will takeWhile it may sound a bit scary, the American space agency Nasa says there's nothing to worry about - despite how close it'll get to Earth, they say it poses no danger to us. In fact, if it got any closer, a lot of it would burn up when it entered our atmosphere (the collection of gases surrounding our planet), and it would become too small to cause any problems.Why do things get hot when they enter our atmosphere?You may have noticed when spacecraft return to Earth, they get red hot when they reach our atmosphereThis is because they're travelling incredibly fast, and that speed compresses (or squeezes) the gas in front of themWhen gas is compressed, it heats upRe-entry temperatures can reach as high as 3,000 degrees Fahrenheit (1,650 degrees Celsius)!Image source, solarseven/gettyImage caption, Space is a vacuum, which means there's no air, which is why things can travel through it quickly without heating up - but when they hit the gases in our atmosphere, they get so hot that they glow like this!Nasa has a system called Scout which assesses objects travelling towards Earth from Space, to see if they pose any danger.Scout quickly ruled out any possibility of Asteroid 2023 BU hitting Earth, said its developer Davide Farnocchia - an engineer at the agency's Jet Propulsion Laboratory in California.Image source, NasaImage caption, Nasa are doing lots of work to protect Earth from asteroids - in fact, they recently launched a test called DART to see if they could deflect any that might threaten our planet by hitting them with a satellite"But despite the very few observations, it was nonetheless able to predict that the asteroid would make an extraordinarily close approach with Earth," Farnocchia said. "In fact, this is one of the closest approaches by a known near-Earth object ever recorded."Not sure what the difference is between an asteroid and a meteor?How big is the asteroid?Image source, MARK GARLICK/SCIENCE PHOTO LIBRARYImage caption, This is an artist's impression of what it may have looked like when the asteroid that wiped out the dinosaurs hit our planetThe asteroid was first discovered on Saturday, and is believed to be between 3.5m (11ft) and 8.5m (28ft) across.This would make it as big as a killer whale, or a truck - however that's relatively small when it comes to asteroids.The asteroid that wiped out the dinosaurs when it hit the Earth is thought to have been anywhere between 10 kilometres (6.2 miles) and 15 kilometres (9.3 miles).You can even visit where it made its impact, although you can't actually see it - the site is called the Chicxulub crater, and it's buried under the Yucatán Peninsula in Mexico.If you cannot see this quiz, click here.More on this story