NASA has been closely monitoring asteroid 2024 YR4, a space rock estimated to measure between 130 and 300 feet (40 – 90 metres) across. While initial calculations indicate a very small chance of impact with Earth on 22 December 2032, astronomers believe that further observations will likely rule out any risk altogether.
According to NASA’s Near-Earth Object (NEO) monitoring system, the asteroid’s trajectory is still being refined. As additional data is collected and incorporated into orbital calculations, scientists expect the probability of impact to drop to zero. However, the asteroid will move beyond the range of Earth-based telescopes by April 2025, making further observations impossible until its next close approach in 2028.
Potential Impact and Damage
While asteroid impacts can pose significant risks, the extent of damage caused depends on various factors, including size, composition, and entry angle. If 2024 YR4 were to enter Earth’s atmosphere, experts suggest an airburst would be the most probable outcome.
An airburst occurring over the ocean would likely have minimal impact, with little to no risk of triggering a tsunami. However, if the asteroid were to explode over a populated area, the effects could be more concerning. A smaller object within the estimated range (130 – 200 feet or 40 – 60 metres) could shatter windows and cause minor structural damage across a city. In contrast, an asteroid at the upper end of the size range (300 feet or 90 metres) could lead to widespread destruction, including the collapse of residential structures and severe damage across larger regions.
NASA’s Monitoring and Response
NASA’s Near-Earth Observations programme funds dedicated observatories to track potentially hazardous asteroids. By analysing observation data, scientists use advanced computer models to predict an asteroid’s future movements and determine any risk to Earth. These models continually update as new data is collected, which explains why impact probabilities change over time.
For the most up-to-date impact probability, NASA advises checking the Sentry risk list, hosted by the agency’s Centre for Near-Earth Object Studies.
Defence Against Asteroids
If an asteroid such as 2024 YR4 were ever confirmed to be on a collision course with Earth, planetary defence measures could be considered. One possible method involves a kinetic impactor, similar to NASA’s Double Asteroid Redirection Test (DART), which successfully altered an asteroid’s trajectory in 2022. However, given the current low probability of impact, NASA stresses that speculation about deflection techniques remains premature.
For now, astronomers continue to observe and refine their understanding of asteroid 2024 YR4’s orbit, ensuring that Earth remains well-prepared for any potential future threats.
