Synodic month ~ 29.5 days
The Moon in the sky, moving ~ 13◦ eastwards in 24 hours, i.e., ~ 0.5◦ in 1 hour
- perigee, at ~ 363,000 km , angular size ~ 33'31"
apogee, at ~ 405,000 km , angular size ~ 29'22"
average distance ~ 384,400 km, angular size ~ 31'5"
orbital velocity ~ 1 km/s
- The plane of the Moon's orbit is 5◦ tilting to the ecliptic.
- The Moon's rotation axis has a 7◦ tilt to its orbit.
- Only ~ 59% of the lunar surface can be seen from the Earth.
(The rotation period of the Moon is equal to its orbital period.)
The decrease of the Earth's spin rate (~ 2 ms per century)
The increase of the distance to the Moon (3 cm per year)
Mercury is already tidal locked with the Sun in a state of 3:2 tidal resonance, i.e., rotation period is 2/3 of the revolution period., which is more stable than 1:1 resonance because of its moderately high orbital eccentricity.
Tidal lock is very often seen in binary systems.