Brightest Lunar Impact Ever Recorded

This artwork depicts the blast formed from an impacting meteor on the lunar surface. Credit: NASA

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.

An image of the flash resulting from the impact of a large meteorite on the lunar surface on 11 September 2013, obtained with the MIDAS observatory. Credit: J. Madiedo / MIDAS
An image of the flash resulting from the impact of a large meteorite on the lunar surface on September 11, 2013, obtained with the MIDAS observatory. Credit: J. Madiedo/MIDAS

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.

Location of Mare Nubium lava basin. Credit: NASA
Location of the Mare Nubium lava basin. Credit: NASA

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.

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Meet the Author
Andrew Fazekas, aka The Night Sky Guy, is a science writer, broadcaster, and lecturer who loves to share his passion for the wonders of the universe through all media. He is a regular contributor to National Geographic News and is the national cosmic correspondent for Canada’s Weather Network TV channel, space columnist for CBC Radio network, and a consultant for the Canadian Space Agency. As a member of the Royal Astronomical Society of Canada, Andrew has been observing the heavens from Montreal for over a quarter century and has never met a clear night sky he didn’t like.