From The New York Times:
The moon, lacking an atmosphere to shield it, is constantly under attack. When meteorites bombard its volcanic surface, sodium atoms fly high into orbit. The sun's photons collide with the sodium atoms, effectively pushing them away from the sun and creating a tail-like structure flowing downstream from the moon.
For a few days each month, when the new moon moves between Earth and the sun, this comet-like tail dusts the side of our world that is facing the sun. Our planet's gravity pinches that sodium stream, narrowing it into a beam, invisible to the naked eye, that wraps around Earth's atmosphere and shoots out into space from the opposite side of the planet.
The rest of the article details the various attempts to capture an image of this beam of sodium space dust — which, according to a recent study, might be hindered by sporadic bursts of meteors.
The cosmos are crazy.
The Moon Has a Comet-Like Tail. Every Month It Shoots a Beam Around Earth. [Robin George Andrews / New York Times]
Image via YouTube
Full disclosure: I also write for Wirecutter, which is part of the New York Times Company, which also owns the New York Times.