NASA has announced that asteroid 2024 YR4 has a more than 1% chance of colliding with Earth, making it the only known large asteroid with such a probability. According to NASA's planetary defense blog, the probability of impact increased to 1 in 32, or 3.1%, from the previously calculated 1 in 42. This development has drawn attention due to the asteroid's potential for localized destruction, as indicated by its Torino Scale rating of 3 out of 10.
The asteroid, measuring approximately 177 feet (54 meters) in diameter, poses a significant threat should it impact Earth. It could unleash energy equivalent to 8 megatons, surpassing the energy released by the Hiroshima atomic bomb more than 500 times. While the chance of a direct hit is significant, there remains a 96.9% likelihood that YR4 will miss Earth entirely.
Asteroid 2024 YR4 is about as wide as the Leaning Tower of Pisa is tall, underscoring its potential to cause catastrophic damage. Despite the current risk assessment, history suggests that additional data often reduces impact probabilities to zero. Many objects on NASA's asteroid risk list have seen their probabilities diminish as more observations become available.
In the unlikely event of an impact, NASA notes that YR4 would likely strike along a "risk corridor" spanning the eastern Pacific Ocean, northern South America, the Atlantic Ocean, Africa, the Arabian Sea, and South Asia. The team's ongoing research aims to refine the asteroid's trajectory and provide a more accurate assessment of its potential threat.
To further understand the risks posed by YR4, a team of scientists has been granted emergency access to the James Webb Space Telescope. The forthcoming observations will offer deeper insights into the asteroid's path and size, helping researchers determine whether the current odds will decrease over time.
NASA emphasizes that while the current probability is notable, it remains highly probable that further observations will lead to a reassessment and likely reduction of the impact risk. As scientists continue to track YR4's movements, they anticipate gaining greater clarity on its trajectory and potential effects.
