A NASA telescope monitoring the Moon recently spotted a bright flash the space agency says was caused by a boulder-sized meteor slamming into the lunar surface. Meteors smash into the Moon fairly frequently, but this collision, which occurred on March 17, was the biggest NASA has ever observed. "It exploded in a flash nearly 10 times as bright as anything we've ever seen before," said Bill Cooke, from NASA's Meteoroid Environment Office. The blast was so bright it was visible to the naked eye. Here, a look at this otherworldly smashup, by the numbers:

Estimated width of the meteor, in feet

Estimated weight of the boulder-sized space rock, in pounds

Width of the crater left by the meteoroid, in feet

Speed, in miles per hour, at which the rock was traveling when it crashed into the lunar surface

Length of time, in seconds, that the explosion glowed as brightly as a fourth-magnitude star, which can be seen without a telescope. "We have seen a couple of others in the 'wow' category but not this bright," said the monitoring program's manager, Robert Suggs. "It jumped out at me."

Tons of TNT it would take to cause an explosion with the same force

Years NASA scientists have been observing the Moon, keeping an eye out for meteor impacts. The Earth's atmosphere tends to burn up most of the meteors that cross its path. The air-less Moon, on the other hand, gets pummeled routinely.

Meteors the space agency has recorded since the monitoring program began. The March 17 event coincided with a surge in meteor detections in Earth's atmosphere. Astronomers think both phenomena might have occurred as the planet and its satellite passed through debris from the asteroid belt between the orbits of Mars and Jupiter. "We'll be keeping an eye out for signs of a repeat performance next year when the Earth-Moon system passes through the same region of space," Cooke said.

Estimated diameter, in feet, of a meteor that slammed into Russia in February. It was the biggest space rock to hit Earth since 1908.

Number of explosions like the one on the Moon that it would take to equal the energy of the one that exploded over Chelyabinsk, Russia

People injured in the Russia incident

Radius, in miles, of the Vredefort crater, the largest known sign of impact on Earth. The crater — in Free State, South Africa — was created about two billion years ago. It was designated a UNESCO World Heritage Site in 2005.

Width, in miles, of the Moon's biggest crater, the South Pole-Aitken basin. It's five miles deep. "This is the biggest, deepest crater on the Moon — an abyss that could engulf the United States from the East Coast through Texas," says Noah Petro of NASA's Goddard Space Flight Center.

Sources: National Geographic, The Huffington Post, NASA,, Sydney Morning Herald, USA Today