With a 1 in 6 million chance of collision, the 1979XB is predicted to crash into Earth in December 2056. However, a much larger possibility of a high-risk impact exists in December 2024. 1979XB was sighted for the first time in December 1979 in Australia by astronomers at the Siding Spring Observatory. Since then it has never been observed again thus being labelled as a lost asteroid. This asteroid belongs to Apollo asteroids, a group of near-Earth asteroids that are found in Earth’s orbital neighbourhood.
On the asteroid impact list formulated by NASA and ESA, 1979XB falls in second place. This list names all asteroids recognized that have a non-zero chance of colliding with Earth. The rank makes 1979XB a highly hazardous near-earth asteroid. ESA compares it to the tallest man-made structure on Earth; the Burj Khalifa. Upon impact, this asteroid has the potential to annihilate a complete city.
1979XB has an approximate diameter of 660-800 m or 2200-2600 feet and takes 1210 days to complete an orbit. Furthermore, its average orbital speed is estimated to be 20.03 km/s. 0.65 AU is the closest 1979XB has been to the sun and 3.81 AU is the farthest. Lastly, 1979XB has a very short observation arc of 3.9 days.