Asteroid 2024 YR4 now has a 1 in 38 chance of impact in 2032

Asteroid 2024 YR4 has been in the headlines in recent weeks as its impact probability continues to rise, earning it the designation of a potential “city destroyer.”

The impact probability of asteroid 2024 YR4 has risen again, now estimated at 2.6% for 2032, equivalent to a 1 in 38 chance, according to NASA’s Jet Propulsion Laboratory (JPL) Center for Near-Earth Object (NEO) Studies.

Meanwhile, the European Space Agency’s (ESA) Near-Earth Objects Coordination Centre (NEOCC) estimates the risk at approximately 2.4%.

Asteroid 2024 YR4 was detected at the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile on December 27, 2024. ATLAS consists of multiple telescopes worldwide and is managed by the University of Hawaii’s Institute for Astronomy.

The increase is not unexpected, as scientists had predicted that the impact probability would rise before declining as more observational data becomes available.

The asteroid’s size is estimated to be between 40 – 90 m (130 – 295 feet). The uncertainty in this estimate arises because scientists study the asteroid based on the sunlight it reflects, meaning measurements vary depending on the asteroid’s surface reflectivity.

Scientists using the James Webb Space Telescope to study the asteroid suggest that it could be either 40 m (130 feet) across and highly reflective or 90 m (295 feet) across and less reflective. Determining an accurate size is crucial, as the impact of a 40 m asteroid would differ significantly from that of a 90 m asteroid.

It is worth noting that impact outcomes would depend on numerous variables, including the asteroid’s material composition, the precise entry angle, and local environmental conditions at the time of impact.

For comparison, the Chelyabinsk asteroid, which exploded over Russia on February 15, 2013, was estimated to be about 20 m (66 feet) in diameter before entering Earth’s atmosphere. The impact released an energy equivalent to 400 – 500 kilotons of TNT, making it 26 – 33 times more powerful than the Hiroshima bomb.

The asteroid entered the atmosphere at a speed of approximately 19 km/s (42 500 mph, 11.8 miles/s) and exploded at an altitude of 29.7 km (18.5 miles) above the ground.

The resulting airburst generated a powerful shockwave, which shattered windows and damaged over 7 200 buildings across six cities. The blast wave injured about 1 500 people, mostly due to flying glass and debris. Despite its relatively small size, the Chelyabinsk event demonstrated the significant destruction that even a moderate asteroid impact can cause when it enters at high velocity.

The explosion produced a fireball brighter than the Sun, which was visible up to 100 km (62 miles) away. The intense heat and pressure caused several meteorite fragments to survive re-entry, with the largest piece—weighing 654 kg (1 442 pounds) — later recovered from Lake Chebarkul.

This event remains the largest recorded asteroid impact since the 1908 Tunguska explosion. Unlike larger asteroids that are actively monitored, the Chelyabinsk asteroid went undetected before impact due to its small size and approach from the Sun’s direction.

In contrast, 2024 YR4, estimated to be 40 – 90 m (130 – 295 feet) wide, would carry significantly more energy.

A 40 m (130 feet) asteroid could release 5 megatons of TNT or more, while a 90 m (295 feet) asteroid could strike the ground, forming a crater up to 1.5 km (0.93 miles) wide and releasing over 100 megatons of energy — more than 200 times the power of Chelyabinsk.

The asteroid’s impact probability remains subject to change as more data is gathered.

The object will move out of view in April and become visible again in 2028, allowing for more precise observations that may help scientists rule out a 2032 impact.

References:

¹ (2024 YR4) — Earth Impact Risk Summary – CNEOS – February 18, 2025

² Asteroid 2024 YR4 – latest updates – ESA – February 4, 2025