NASA Meteoroid-Spotting Program Captures Brightest-Yet Moon Impact

From a NASA press release published Friday: "For the past 8 years, NASA astronomers have been monitoring the Moon for signs of explosions caused by meteoroids hitting the lunar surface. 'Lunar meteor showers' have turned out to be more common than anyone expected, with hundreds of detectable impacts occurring every year. They've just seen the biggest explosion in the history of the program." Watch the flash for yourself.

Re:So what substance exploded?

[Bieeanda]

The original article addresses this in a footnote:

The Moon has no oxygen atmosphere, so how can something explode? Lunar meteors don't require oxygen or combustion to make themselves visible. They hit the ground with so much kinetic energy that even a pebble can make a crater several feet wide. The flash of light comes not from combustion but rather from the thermal glow of molten rock and hot vapors at the impact site.