NASA has released a map of 100 explosions on the Moon, observed in just the last two and half years (news coverage). If you want to live up there, you’d better get a hard hat.
“They’re explosions caused by meteoroids hitting the Moon,” says Bill Cooke, head of NASA’s Meteoroid Environment Office at the Marshall Space Flight Center (press release). “A typical blast is about as powerful as a few hundred pounds of TNT and can be photographed easily using a backyard telescope.”
NASA started up its Moon explosion monitoring towards the end of 2005. As they were planning to send astronauts back there “it seemed like a good idea to measure how often the Moon was getting hit”, says Rob Suggs, also at the Marshall centre.
The NASA team found there is no time of year when impacts fall to zero. Meaning if, and it’s a big if, there is to be a space colony on the Moon, they’ll need some form of protection.
Meteoroids hit the Moon so fast, normally at least 13,000 m/s, that they heat up the surface enough that it glows. Hence you get an ‘explosion’ despite a lack of oxygen.
Video of an impact below the fold.
Image top: map of impacts Science@NASA