The locking of the rotation of a body to its revolution around another body through gravitational forcing. (also known as spin orbit lock)
The lunar lowlands filled by successive flows of dark lava; from the Latin word for sea. (singular "mare").
A narrow, winding valley on the moon caused by ancient lava flows along narrow channels.
Meteorite of microscopic size. These meteorites are especially important for airless worlds as they produce regolith (ex: the moon).
The age of a geological feature referred to other features. For example, relative ages reveal that the lunar maria are younger than the highlands.
Rock of aluminum and calcium silicates found in the lunar highlands. Also known as the genesis rock, the oldest known rock in the solar system at 4.1 billion years old.
Strangely disturbed regions of the moon opposite the locations of the Imbrium Basin and Mare Orientale.
The theory that the moon formed elsewhere in the solar system and was later captured by Earth.
large impact theory
The theory that the moon formed from debris ejected during a collision between earth and a large planetesimal.
The coincidental agreement between two periodic phenomena; commonly applied to agreements between orbital periods, which can make orbits more stable or less stable.