An asteroid the size of a London bus will make its fourth-closest approach to Earth this week.
The space rock, known as 2023 BU, was discovered by NASA just last weekend but is due to be revealed this Friday (Thursday 27).
Most asteroids are beyond the distance of the moon – which is 240,000 miles away – but this one is much closer and will be next for 300 years.
The object is about half the size of the famous Chelyabinsk meteor that hit Earth in 2013.
Don’t look up! A London bus-sized asteroid known as 2023 BU will make fourth-closest approach to Earth this week (stock image)
The space rock, known as 2023 BU, was discovered by NASA just last weekend but is scheduled to arrive this Friday (Thursday 27)
What is a “potentially dangerous” asteroid?
A potentially hazardous asteroid (PHA) is an asteroid whose orbit is closer than 0.05 AU (about 7.5 million km) to Earth.
It is also at least 100 meters (300 feet) in diameter.
The International Astronomical Union claims there are around 1,500 potentially dangerous asteroids.
While not yet a threat to Earth, asteroids of this size have the potential to wreak havoc if they land on our planet, especially in densely populated areas.
It is believed that one hits the earth once every 200-300 years.
The asteroid is expected to make the fourth-closest pass of more than 35,000 past and future approaches to Earth, according to NASA’s Center for Near Earth Object Studies (CNEOS), which includes data for the period 1900-2200.
A live stream hosted by the Virtual Telescope Project (VTP) in Italy will be made available on Thursday from 19:15 GMT (14:15 ET) for viewers to catch the event.
This will be the only way to see the asteroid — 2023 BU is so small that it shines at a maximum of magnitude 11.3, which is too faint to be seen with the naked eye.
Instead, it must be picked up by large, powerful telescopes such as the VTP’s 14-inch and 17-inch robotic telescopes at Ceccano.
The space rock will hurtle past Earth at 33,000 miles per hour, 6,500 miles (10,500 km) from the center of our planet and 2,100 miles (3,400 km) from the surface.
It measures approximately 12.4 feet by 27.8 feet, which is about the same size as the original Routemaster London bus.
Despite being spotted just five days ago, experts have calculated its orbit and insist there is no chance 2023 BU will hit Earth on this particular approach.
But even if it did, there’s a good chance it wouldn’t reach the surface.
Space rocks smaller than 25 meters are most likely to burn up when they enter Earth’s atmosphere, NASA says, causing little to no damage to the ground.
While it won’t affect us, by some definitions the asteroid will technically pass through the top region of our planet’s atmosphere known as the “exosphere.”
This is said to extend from about 6,000 miles (10,000 km) to a maximum distance of 120,000 miles (193,000 km) above the earth.
Comparison: The Space Rock measures about 12.4 feet by 27.8 feet, which is about the same size as the original London Routemaster bus
Despite being spotted just five days ago, experts have calculated its orbit (pictured) and insist there is no chance 2023 BU will hit Earth on this particular approach
A live stream hosted by the Virtual Telescope Project (VTP) in Italy will be made available on Thursday from 19:15 GMT (14:15 ET) for viewers to catch the event
Known as 2023 BU, the object is about half the size of the famous Chelyabinsk meteor (pictured) that struck Earth in 2013. It will be closest point to Earth this Friday (January 27) at around 00:30 GMT (19:30 ET on Thursday)
Why was the asteroid 2023 BU just seen?
Some asteroids can “sneak up” on us thanks to a quirk of the Earth’s rotation that makes them appear like they’re barely moving — making them hard to spot.
That’s the warning from NASA-funded experts who studied how telescopes nearly missed a 328-foot-wide asteroid that was 43,500 miles from Earth in 2019.
Dubbed ‘2019 OK’, the space rock was the first object of its size to come this close to our planet since 1908 – but it was only spotted 24 hours before its closest approach.
The reason, the team found, is that it was moving toward us in such a way that its motion across the night sky was counteracted by the Earth’s rotation.
Therefore – for early warning systems like Pan-STARRS1 at Haleakala Observatory in Hawaii – 2019 OK looked stationary, so did not trigger the automatic detection software.
In fact, the experts said, up to half of the asteroids approaching Earth from a danger zone east of the “opposition” likely experience periods of such apparent slow motion.
However, most scientists do not consider this region to be a true part of Earth’s atmosphere because the air is so thin.
Despite this, asteroid 2023 BU will fly by well within geostationary satellite orbit over South America, but still far from the International Space Station at 250 miles (400 km) from Earth.
The space rock was discovered on Saturday by astronomer Gennadiy Borisov at the Crimean Astrophysical Observatory in Nauchnyi, Crimea.
He is famous for discovering the first comet ever seen, called 2I/Borisov, which had traveled into the solar system from interstellar space.
2023 BU orbits the Sun every 425 days while its orbit occasionally intersects Earth’s orbit around our star.
It will next pass relatively close to us on December 6, 2036, but will be well outside the Moon’s orbit.
NASA considers the asteroid a “near-earth object” (NEO) because its orbit puts it within 120 million miles (195 million km) of the Sun, but it’s not a “potentially hazardous asteroid” because it doesn’t large enough to cause significant damage on impact.
In February 2013, a meteor that streaked across the southern Urals and landed in Chelyabinsk, Russia, was the largest recorded meteorite impact in more than a century.
More than 1,600 people were injured by the shock wave from the blast, estimated to be as powerful as 20 Hiroshima atomic bombs, as it landed near the city.
The 19 meter diameter fireball blasted into Earth’s atmosphere at 41,600 miles per hour and much of it ended up in a local lake called Chebarkul.
Last year, experts warned that some asteroids can “sneak up” on us thanks to a quirk of the Earth’s rotation that makes them appear like they’re barely moving — making them hard to spot.
In fact, they said that up to half of the asteroids approaching Earth from a danger zone east of the “opposition” are likely to experience periods of such apparent slow motion.
The NASA-funded experts examined how telescopes nearly missed a 328-foot-wide asteroid that was 43,500 miles from Earth in 2019.
Astronomers are looking for asteroids larger than 450 feet as they can cause ‘catastrophic damage’
Researchers have spotted most asteroids around a kilometer in size, but are now on the lookout for those around 140m (459ft) – as they could cause catastrophic damage.
Although no one knows when the next big impact will happen, scientists are under pressure to predict – and intercept – its arrival.
Artist’s impression shown
“Sooner or later we will get … a small or large impact,” said Rolf Densing, who heads the European Space Operations Center (ESOC) in Darmstadt
It may not happen in our lifetime, he said, but “the risk of some devastating event hitting Earth one day is very high.”
“There’s little we can do at the moment.”
Source: AFP