Meteoroid Hits the Moon: The Movie

Last month, astronomers watched a meteoroid blast a hole in the lunar Sea of Clouds. Their video of the event is a must-see.

The video plays in 7x slow motion; otherwise the explosion would be nearly invisible to the human eye. "The duration of the fireball was only four-tenths of a second," says Bill Cooke, the head of NASA's Meteoroid Environment Office in Huntsville, AL. "A student member of our team, Nick Hollon of Villanova University, spotted the flash."

Taking into account the duration of the flash and its brightness (7th magnitude), Cooke was able to estimate the energy of impact, the dimensions of the crater, and the size and speed of the meteoroid. "It was a space rock about 10 inches (25 cm) wide traveling 85,000 mph (38 km/s)," he says.

If a rock like that approached Earth, it would never reach the ground. "Earth's atmosphere protects us," Cooke explains.
"A 10-inch meteoroid would disintegrate in mid-air, making a spectacular fireball in the sky but no crater."  The Moon is different. Having no atmosphere, it is totally exposed to meteoroids. Even small ones can cause spectacular explosions, spraying debris far and wide.

The movie can be seen at:
http://science.nasa.gov/headlines/y2006/
13jun_lunarsporadic.htm?list835304

NASA Science News

Latest news stories..

• Get our news headlines for your website • Submit your news story