Video Scientists have reported spotting the biggest meteorite impact ever seen on the Moon's surface – after a 400kg (900lb) rock slammed into the lunar regolith at an estimated 17km/s, leaving a crater about 50 metres wide.
The impact was seen on September 11 by the Moon Impacts Detection and Analysis System (MIDAS) in Seville, Spain, although the video was made public this week. MIDAS focusses multiple telescopes on the Moon with the aim of catching just such a crash landing. The plasma generated by the meteor's impact caused an 8.3-second flare of light that was visible with the naked eye and was the equivalent of more than 15 tons of TNT being blown up.
"This is the largest, brightest impact we have ever observed on the Moon," Professor Jose Madiedo, of the University of Huelva in south-western Spain, part of the MIDAS team, told the BBC.
"Usually lunar impacts have a very short duration - just a fraction of a second. But the impact we detected lasted over eight seconds. It was almost as bright as the Pole Star, which makes it the brightest impact event that we have recorded from Earth."
The report on the space rock smash, published in the latest Monthly Notices of the Royal Astronomical Society, stated that the flash was about three times as large as that reported by NASA last year. The MIDAS team hopes that NASA's Lunar Reconnaissance Orbiter will be able to survey the new crater and determine more about the meteorite in question.
It's possible that the doomed rock came from the debris tail of the comet Swift-Tuttle, which gives the annual Perseids meteor shower here on Earth, but the team also notes it may be a wandering chunk of space rock left over from the formation of the solar system. The possibility of it being a poorly driven space craft was not discussed. ®