TheMoon has a comet-like tail ofsodium atoms too faint to be detected by thehuman eye. Hundreds of thousands of kilometers long, the feature was discovered in 1998 as a result of scientists fromBoston University observing theLeonidmeteor shower.[1][2][3]
The Moon is constantly releasingatomic sodium as a fine dust from its surface due tophoton-stimulateddesorption,solar windsputtering, andmeteoriteimpacts.[4]Solar radiation pressure accelerates the sodium atoms away from theSun, forming an elongated tail toward theantisolar direction.
The continual impacts ofsmall meteorites produce a constant "tail" from the Moon, but the Leonids intensified it,[5] thus making it more observable fromEarth than usual.[6]
TheIndian Space Research Organisation's (ISRO)Chandrayaan-2 mission discovered an abundance of sodium on the Moon in October 2023.[7]
