So you were taught that you can see 50% of the moon's surface because it presents only one face toward Earth, right?
Wrong!
The Moon generally does have one hemisphere facing the Earth due to tidal locking however, this simple picture is only approximately true. Over time, somewhat more than half (about 59%) of the Moon's surface is seen from Earth due to libration.
The image below shows (primarily) one of three types of librations occurring with the moon as seen from Earth. Libration in longitude results from the slight eccentricity of the Moon's orbit around Earth; the Moon's rotation sometimes leads and sometimes lags its orbital position, causing us to be able to see slightly beyond the lunar eastern and western horizons. The GIF shows the moon through a 29 day period- approximately one lunar cycle/month.
I suppose that libration c-o-u-l-d be mistaken for a night of libation.
Wrong!
The Moon generally does have one hemisphere facing the Earth due to tidal locking however, this simple picture is only approximately true. Over time, somewhat more than half (about 59%) of the Moon's surface is seen from Earth due to libration.
The image below shows (primarily) one of three types of librations occurring with the moon as seen from Earth. Libration in longitude results from the slight eccentricity of the Moon's orbit around Earth; the Moon's rotation sometimes leads and sometimes lags its orbital position, causing us to be able to see slightly beyond the lunar eastern and western horizons. The GIF shows the moon through a 29 day period- approximately one lunar cycle/month.
I suppose that libration c-o-u-l-d be mistaken for a night of libation.
