Sodium tail of the Moon

The Moon has been shown to have a "tail" of sodium atoms too faint to be detected by the human eye. Hundreds of thousands of kilometers long, the feature was discovered in 1998 as a result of scientists from Boston University observing the Leonid meteor shower.^[1][2][3]

The Moon is constantly releasing atomic sodium as a fine dust from its surface due to photon-stimulated desorption, solar wind sputtering, and meteorite impacts.^[4] Solar radiation pressure accelerates the sodium atoms away from the Sun, forming an elongated tail toward the antisolar direction.

The continual impacts of small meteorites produce a constant "tail" from the Moon, but the Leonids intensified it,^[5] thus making it more observable from Earth than usual.^[6]

ISRO's Chandrayaan-2 discovered an abundance of sodium on the Moon in October 2023.^[7]

See also

• Solar System portal

• Atmosphere of the Moon
• Lunar Atmosphere and Dust Environment Explorer