Video Astronomers reckon a 220-million-kilogram asteroid is going to swing by Earth in 2032 with a 1-in-100 chance of hitting us.
On Christmas Day, a NASA-operated robot telescope was taking in the night sky in Chile when it caught sight of an object that activated the space agency's Asteroid Terrestrial Last Alert System. This prompted scientists to investigate, and two days later, they figured whatever it was, it was zooming away from our home world - but on a trajectory could bring it back our way.
If it were to whack into our planet, it would be like an eight-mega-ton TNT bomb going off, about 500 times larger than the nuke dropped on Hiroshima in World War II, we're told. Gaze upon the terrifying dot in the video below, captured by a European telescope in Chile, for it is the asteroid in question. And 2024 YR4 be its name.
Youtube Video
"At this point astronomers have measured the object's orbit, and further observations will refine that orbit to give us a more precise understanding of its potential danger," said Heidi Hammel, science veep at the Association of Universities for Research in Astronomy.
"We have a rough estimate of its size based on its brightness, and from variations in the brightness, we can infer that it has an elongated shape. Measurements at visible wavelengths suggest it may be a stony asteroid."
Information on 2024 YR4 is still being collated. We do know for now that the space rock is thought to be 40 to 90 metres (130 to 300 feet) in diameter - as wide as 886 standard four-inch cans of spam laid end to end - and is moving away from Earth at 17.32 km/s (38,700 MPH). It'll stay in sight from our planet until April before disappearing around the Sun and won't be seen again until 2028.
"The asteroid's orbit around the Sun is elongated (eccentric)," the European Space Agency said. "It is currently moving away from Earth in almost a straight line, making it difficult to accurately determine its orbit by studying how its trajectory curves over time."
That orbit is going to be crucial as 2024 YR4 is now the highest-ranked near-Earth object (NEO) on the Torino Impact Hazard Scale, where one is all clear, and 10 the end of life on Earth as we know it. 2024 YR4 is ranked at three, making it the most dangerous NEO on the books today.
Practically speaking, though, astronomers estimate there's only a 1.3 percent chance of 2024 YR4 hitting us. The orbital track suggests it'll fly some distance above the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia. That distance hasn't been shared yet; it's likely to be comfortably large, it may be quite uncomfortably small.
Given the asteroid's proportions, it's gonna leave a mark if it decides to abruptly check into Hotel Earth, and might trigger a tsunami if it hits the ocean, but it won't be a harbinger of extinction. It has a mass similar to the meteorite that blew up a few hundred miles of Russian taiga in the 1908 Tunguska impact. The International Asteroid Warning Network says [PDF] the worst-case blast radius for 2024 YR4 would probably be about 50 km (31 miles), and you can simulate such impacts here.
Right now all efforts are on tracking the NEO to determine its orbit as exactly as possible. The European Southern Observatory's Very Large Telescope in Chile, for one, is following the object so that astroboffins can use the latest readings to adjust their predictions.
Don't forget that in 2004 an asteroid dubbed 99942 Apophis was spotted, and at a quarter of a mile wide it makes 2024 YR4 look kinda puny. It reached four on the Torino scale, and was due to either smash somewhere in the Pacific in 2029 or 2036. Subsequent observations, though, confirmed we're safe from Apophis for the next century at least. ®