A meteorite that struck the Moon in September 2013 triggered a flash so bright that anyone on Earth could have easily seen it had they been looking at the right time, according to new research on the celestial event published in the journal Monthly Notices of the Royal Astronomical Society.
The explosion was the largest ever seen on the Moon, the researchers revealed, noting that the space rock with the mass of a small car hit the Moon with the force equal to about 15 tons of TNT, at least three times more powerful than the largest known lunar impact before this.
Monday, video footage of the Sept. 11, 2013 lunar impact was released by the University of Huelva in Spain
The footage reveals a bright flare on the lunar surface that researchers report grew as bright as the North Star Polaris.
Jose Madiedo, a professor at University of Huelva, was recording the Moon using telescopes that are part of the the Moon Impacts Detection and Analysis System (MIDAS) observatory. The recording he made shows the meteorite impacting the lunar surface and sustaining an eight-second afterglow. Most impacts like this can be observed for just a second.
"At that moment I realized that I had seen a very rare and extraordinary event," Madiedo said in a statement.
Madiedo and his colleague Jose Ortiz, from the Institute of Astrophysics of Andalusia, calculated that the meteorite hit the Moon at 61,000 kilometers per hour (37,900 mph) and created a 40-meter (130 foot) wide crater in a sector of the Moon known as as Mare Nubium.
The event, which was the longest and brightest of its kind ever recorded on the Moon, caused such a display because the Moon lacks an atmosphere like Earth's, which would have caused the space rock to burn up upon entry.
The asteroid that hit the Moon is thought to be about 1 meter in width. To have an impact on Earth, a meteorite would need to be much larger. The Chelyabinsk asteroid that exploded over Russia in February 2013, for example, was estimated to be about 19 meters wide and hit the atmosphere with was was estimated to be equal to 500,000 tons of TNT, causing a shockwave the caused widespread damage and injury.
The video above shows the raw footage of the lunar impact. The video below gives more detail about the event.