NASA has upgraded the impact risk for a massive asteroid recently discovered by Ukrainian observers that will pass close to the Earth in 2032, although a collision remains unlikely.

According to an update on NASA’s Near Earth Object Program site, the impact risk is now 1 in 9,090; up from 1 in 63,000 at the time the asteroid, identified as 2013 TV135, was discovered.

NASA has upgraded the impact risk for a massive asteroid recently discovered by Ukrainian observers that will pass close to the Earth in 2032, although a collision remains unlikely.

According to an update on NASA’s Near Earth Object Program site, the impact risk is now 1 in 9,090; up from 1 in 63,000 at the time the asteroid, identified as 2013 TV135, was discovered.

However, the updated figures still mean that the chance of the asteroid completing a safe flyby is 99.989 percent, slightly down from 99.992 percent in the original estimate.

The 400-meter-wide asteroid, discovered by an observatory in Ukraine’s Crimea earlier this month, is one of two asteroids to currently rank above zero on the 10-degree Torino Scale, which estimates asteroid impact hazards.

Both score 1, but impact risks are constantly revised in line with new observations. A case in point is 99942 Apophis, a 325-meter-wide asteroid that briefly ranked a 4 in 2004, but was downgraded to zero last spring.

Although it remains statistically unlikely, if 2013 TV135 were to collide with the Earth, it would create an explosion estimated to be equivalent to 2,500 megatons of TNT – 50 times greater than the biggest nuclear bomb ever detonated