Risk of Football Pitch-Sized Asteroid Hitting Earth Doubles in a Week

The risk of an asteroid impact on Earth has doubled within a week, though there are currently no plans to build a deflection spacecraft for the 90-metre-wide space rock.

The asteroid, designated 2024 YR4, was first detected two days after it passed Earth on Christmas Day 2024 by a telescope in Chile. Latest calculations indicate a 2.3% chance of impact on December 22, 2032, nearly double the 1.2% risk estimated last week.

Monitoring the Threat

Any impact probability above 1% for an asteroid larger than 50 meters prompts a global expert discussion. NASA and the European Space Agency (ESA) have placed 2024 YR4 at the top of their asteroid risk registers.

NASA estimates that 2024 YR4 weighs nearly a quarter of a million tonnes and could explode with the force of 2.2 million tonnes of TNT, equivalent to 150 times the Hiroshima atomic bomb.

Potential Impact Locations

While the UK is not at risk, potential impact zones include:

- Western African cities such as Lagos and Accra

- Mumbai, India

- South American countries, including Venezuela and Colombia

If it were to strike, the asteroid could flatten a city, causing local devastation. A similar-sized asteroid impacted Siberia in 1908, flattening 1,000 square miles of forest.

Future Observations and Risk Assessment

Astronomers will continue tracking the asteroid until it disappears from view in May, refining predictions about its trajectory and potential threat. While ongoing observations have increased the estimated risk, officials anticipate that further analysis will likely reduce the probability to zero.

Currently, the 2.3% risk is comparable to randomly drawing the ace of spades from a full deck or rolling two sixes with two dice, meaning the likelihood of an actual impact remains low.