2024 YR4, ‘city-killer’ asteroid headed for Earth; when and where it will hit us

Scientists are closely watching a newly discovered asteroid — 2024 YR4 — whose chances of hitting Earth just before Christmas in 2032 are rising.

The asteroid 2024 YR4 was first spotted by the El Sauce Observatory in Chile on Dec. 27. It's estimated to be between 130-300 feet wide and had a 1.3% chance of striking Earth. However, those chances have since increased to 2.3% as of Thursday, according to NASA and the International Asteroid Warning Network (IAWN).

"An asteroid this size impacts Earth on average every few thousand years and could cause severe damage to a local region," the European Space Agency said in a statement.

In comparison, this is not like the largest asteroid ( 6.2 mile diameter) to hit planet Earth 66 million years ago that led to the extinction of dinosaurs, albeit the last hit to the planet was in 2013 by smaller Chelyabinsk Meteorite (66 foot diameter) that fell in Siberia, Russia that was still powerful enough to injure 1,500 people and damage thousands of buildings across six cities.

However, for scale, Bruce Betts, chief scientist of The Planetary Society, said in a news report, "If you put it over Paris or London or New York, you basically wipe out the whole city and some of the environs." 

According to the Torino Impact Hazard Scale, used to measure the impact predictions of asteroids and comets, 2024 YR4 ranks 3 out of 10 of the yellow zone, considered a "close encounter" or “meriting the attention by astronomers,” stated the European Space Agency.

While the exact trajectory is still not known, the IAWN memo states that the possible impact sites include over the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia.

Director Paul Chodas of the NASA JPL Center for NEO Studies said that although the odds look like 1 in 63 chance of a direct hit, there's still a much better chance of a miss. He likened it to how the National Weather Service determines the chances of hurricanes making landfall.

"It's kind of analogous to having a major city such as New Orleans in the cone of uncertainty of a hurricane," Chodas says.

Chodas said the odds of 2024 YR4 striking Earth "could fall to zero almost any day now," he said. "But we don't know that."