On March 17, scientists monitoring the moon for meteorite impacts spotted the biggest impact event to date: a space rock the size of a basketball slammed into the lunar surface at a speed of 56,000 miles per hour (90,000 km/hr), creating a new crater around 20 meters wide.
"On March 17, 2013, an object about the size of a small boulder hit the lunar surface in Mare Imbrium," said Bill Cooke of NASA's Meteoroid Environment Office in a statement over the weekend. "It exploded in a flash nearly 10 times as bright as anything we've ever seen before."
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Indeed, the flash was impressive - it unleashed the equivalent energy of 5 tons of TNT exploding and would have been visible to anyone casually looking at the moon, no telescope required.
The impact was captured by a NASA program monitoring impact events during "lunar meteor showers." When small pieces of rock - meteoroids - hit the Earth's atmosphere, they produce a bright streak of light as they burn up. These are "meteors." On the moon, however, there is no atmosphere, so the meteoroids directly hit the lunar surface, creating an energetic flash.