Astronomer sees asteroid smashing into Moon
February 25, 2014 - 12:11:15 am
PARIS: A Spanish astronomer yesterday said he had witnessed a fridge-sized asteroid smash into the Moon, in the biggest lunar impact by a space rock ever recorded.
The rare episode was seen by Jose Maria Madiedo, a professor at the University of Huelva, Britain’s Royal Astronomical Society (RAS) said.
On September 11 last year, Madiedo was operating two lunar-observing telescopes when he spotted a flash in the Mare Nubium, an ancient, dark lava-filled basin.
The flare was briefly almost as bright as the northern hemisphere’s Pole Star, the RAS said.
It would have been visible to the naked eye to anyone who happened to be looking at the Moon at that moment in good viewing conditions, the RAS said.
There followed a long afterglow, lasting another eight seconds — the longest and brightest ever seen for a lunar impact.
“At that moment, I realised that I had seen a very rare and extraordinary event,” Madiedo told the society.
Madiedo and colleagues calculate that the rock had a mass of around 400 kilos, with a diameter of between 60 centimetres and 1.40 metres.
It hit Mare Nubium at around 61,000 kilometres per hour. Madiedo has posted two clips on Youtube (http://youtu.be/perqv4qByaI and http://youtu.be/zCFDkj2JtyA).
The speed was so high that the rock turned molten on impact and vaporised, leaving a thermal glow visible from Earth as a flash, and bequeathing a 40-metre crater in the Moon’s pocked
The impact energy was equivalent to an explosion of around 15 tonnes of TNT.