NASA astronomers have been continuing to monitor the trajectory of asteroid 2024 YR4. The initial calculations suggested a 1.3% probability of an Earth impact event, which temporarily increased to 3.1% as more data came in. However, and with a sigh of relief, recent analysis brings encouraging news: the Earth impact probability has decreased significantly to 0.28%, though calculations now show a 1% chance of lunar impact. Observations will continue with the James Webb Space Telescope so stay tuned.
Asteroids are rocky, airless worlds that are remnants left over from the formation of our Solar System about 4.6 billion years ago. They range in size from tiny pebbles to massive bodies hundreds of kilometres across. Most asteroids are found in the asteroid belt between the orbits of Mars and Jupiter although some follow paths that bring them closer to Earth. Occasionally, they can pose a threat to Earth, which is why astronomers and space agencies closely monitor their orbits and develop potential deflection techniques.
Asteroid 2024 YR4 is one such asteroid that has had gripped the nations media over recent weeks. It’s a near-Earth object that was discovered on 27 December 2024, by the Asteroid Terrestrial-impact Last Alert System (ATLAS) in Chile. Initially, it had an estimated 1.3% chance of impact with Earth in 2032, making it one of the highest-risk asteroids ever recorded. However, further observations raised that risk!
Astronomers use systems like ATLAS to identify near-Earth objects (NEOs) that could pose a potential threat to our planet. It was developed by the University of Hawaii and funded by NASA and consists of a network of telescopes positioned around the world to provide continuous sky surveys. Its primary goal is to detect asteroids before a potential impact, allowing for timely warnings and mitigation efforts. Since its installation, ATLAS has successfully discovered thousands of asteroids, including hazardous ones just like 2024 YR4.
Understanding the level of threat from asteroids like 2024 YR4 requires time, time and observations. Imagine a game of tennis and the ball is hit, sending it flying over the net. A photographer sat in the crowd grabs a snapshot of the ball as it flies over the net. The picture is a clear, sharp capture of a point in time however analysis of the image can only reveal the exact location of the ball and not its trajectory. It’s the same with asteroids, once they are discovered, a single observation will reveal where it is but a series of observations are required to understand where it’s going. Ok so this is a simplistic view but it shows how important continued observations are to asteroids like 2024 YR4.
Further observations of asteroid 2024 YR4, conducted during the night of 19-20 February have revealed encouraging results. NASA’s planetary defence team have reported that the probability of an Earth impact has decreased to 0.28%. Monitoring will of course continue to refine trajectory predictions, but current calculations indicate a slight increase in the possibility of lunar impact, now estimated at 1%. These percentages are of course tiny and pose no cause for alarm but 2024 YR4 will continue to be observed over the coming months, just to be sure.
Source : Additional Observations Continue to Reduce Chance of Asteroid Impact in 2032
