Anyone looking up at the right moment on September 11, 2013, may have caught sight of a brief flash of light on the moon.
The flash was the biggest and brightest lunar impact ever observed by astronomers, a new Monthly Notices of the Royal Astronomical Society report finds. The space rock hit with the heft of a golf cart smacking into the lunar surface at a speed of 37,900 miles an hour (61,000 kilometers an hour).
The rock smashed into the moon with enough force to carve out a crater 130 feet (40 meters) wide, causing a visual burst that would have been easily seen by the naked eye—one as bright as the North Star. Astronomers estimate that the rock weighed in at some 882 pounds (400 kilograms) with a width of 2 to 4.6 feet (0.6 to 1.4 meters) wide.
With an impact energy equal to an explosion of about 15 tons of TNT, the meteor impact is estimated to have been at least three times larger than the previously identified largest lunar impact observed by NASA in March of last year.
This rare lunar smashup was caught on film, seen through telescopes operated by astronomer Jose M. Madiedo who was on the hunt for just such events in southern Spain. Scanning his recordings, he immediately noticed an unusually long and bright flash in one of the major, dark-colored lunar lava basins called Mare Nubium, on the unlit portion of the crescent moon.
See for Yourself
While it is unlikely that someone may have caught the exact moment of this lunar flash with the naked eye, it is quite easy for you to find the location of the event.
The impact site officially known as Mare Nubium or Sea of Clouds is a massive impact basin itself, one that filled with lava billions of years ago. This molten rock then froze in place, erasing much of the old craters that then populated the basin.
It now stretches across some 95,000 square miles (245,000 square kilometers) of the southern left portion of the moon’s face and it is easily identified with the naked eye or binoculars as a visibly dark patch on the face of the moon.