The asteroid 2024 YR4 now has a 3.1% chance, or one in 32, of hitting Earth on Dec. 22, 2032, according to NASA data updated Tuesday.

The asteroid was previously assessed to have a 2.3% chance of hitting Earth on Feb. 7 and a 1.2% chance of striking the planet last month.

The asteroid is thought to be 130 to 300 feet based on its brightness, though NASA's James Webb Space Telescope is working to narrow down that range. If it entered our atmosphere and fell to the ground, it would hit Earth at around 38,000 mph, NASA said.

By comparison, an asteroid 165 feet wide produced the Meteor Crater in Winslow, Arizona, which is a mile across, according to NASA.

The composition of the asteroid also matters. An iron asteroid, for example, would be harder and likelier to weather entry into the atmosphere before punching into the Earth. A stone asteroid could explode before impact.

"The main comparison point we have for a stony asteroid impact of this magnitude is Tunguska," Kathryn Kumamoto, head of the Lawrence Livermore National Laboratory Planetary Defense Program, told The New York Times.

The Tunguska blast in 1908 exploded over Siberia, affecting an area 830 miles wide and toppling about 80 million trees, NASA said. A hypothetical explosion of 2024 YR4 could be more or less harmful than that depending on where it occurs.

Direct impact would create a blast that would likely kill anyone at ground zero, then produce a wave that would hit people miles away.

"People within the local region would be at risk of serious injury," Ms. Kumamoto said.

As for where it would hit, some scientists at NASA's Catalina Sky Survey in Arizona have projected a risk corridor. A number of countries around and just north of the equator, from the northern parts of South America, the northern portions of sub-Saharan Africa, India and parts of southeast Asia, lie within it, according to Wired.