NASA scientists have recorded what they say is the largest explosion ever seen on the Moon. A meteoroid roughly the size of a small boulder crashed into the moon, creating a large explosion that NASA says could have been seen with the naked eye. The meteoroid was said to have weighed around 90 pounds and was traveling at approximately 56,000 mph when it crashed into the moon.
To put the explosion into perspective here on Earth, the explosion was said to have the same amount of force as five tons of TNT. Of course, that's not even close to what an atomic bomb can pull off, nor a typical large explosion like what've seen recently in Texas at the fertilizer planet. However, with the vacuum of space and no gravity to slow anything down, the explosions can be much larger on the moon.
This specific explosion, which happened around two months ago, was ten times brighter than anything that NASA has ever seen before. Meteor impacts on the Moon are nothing new, and they happen all the time, but this explosion was unique and it's said to have made a crater over 20 meters (65 feet) across.
So how does an explosion happen on the Moon if there's no oxygen to activate it? NASA says that lunar meteors don't require oxygen or combustion to explode. Meteors hit the Moon surface with so much kinetic energy that NASA says even a small pebble can make a crater that's a few feet wide. As for the flash of light from the meteor explosion, that's from the "thermal glow of molten rock and hot vapors" during impact.
NASA created a specific program to identify how often lunar meteor strikes occur in 2005, and this was the largest explosion that the program has ever seen in its roughly nine years of being active. During that time, scientists have identified over 300 explosions, most which happened during meteor showers on Earth and were rather dim. The program is essentially studying the where, when, and how often of meteor strikes on the Moon to determine the best time and location for future spacewalks on the Moon, if NASA ever decides to go back.