Features:

  1. "The most influential environmental photograph ever taken."---Galen Rowell (1940--2002).

    It's a long road home.

  2. The photo was taken by astronaut William Anders (1933--) on Apollo 8, 1968 Dec24.

  3. Because of tidal locking (AKA synchronous rotation), the Moon's orbital period and rotational period are the exactly same on average and the Moon always turns one side toward the Earth, the near side of the Moon.

    So Selenites would always see the Earth at an approximately fixed point in the sky relative to the surface: i.e., at approximately fixed horizontal coordinates. There would be a little motion due to lunar libration.

    Thus, earthrise could only be seen from an orbiting spacecraft.

  4. How long is a low-orbit orbital period for the Moon?

    Kepler's 3rd law applied to the Moon is

          p = sqrt[4*π**2/(GM)]*r**(3/2) = 108.27 minutes * (r/r_moon)**(3/2) ,

    where the gravitational constant G=6.67384*10**(-11) in MKS units, r = 1737.10 km is the mean lunar radius, and M = 7.3477*10**22 kg is the lunar mass (see Wikipedia: Moon).

    So one can see that relatively low lunar orbits should be ∼ 2 hours.

  5. Mike Collins (1930--2021) who was the Apollo 11 astronaut who stayed with the lunar orbiter said---if I recall correctly---that it was pretty lonely orbiting on the far side---he was out of touch with Earth and nearly as far from humankind as anyone has every been---the rising of the Earth must have been a welcome sight.