The Astronomy Picture of the Day site is a daily visit for me. It’s one of the few non-blogs on the sidebar down there to the right. I love today’s image of the moon passing between Earth and the Deep Space Climate Observatory.
The APOD page doesn’t mention two things that struck me. First notice how dusky the moon appears, especially in contrast to the white clouds of our planet. Then imagine how bright the moon seems in our sky and consider how much brighter the Earth would appear from our natural satellite a quarter of a million miles away.
While the lunar far side doesn’t have large dark patches that we see from Earthside, there is a large basin, a crater 1600 miles across. The South Pole-Aitken basin is visible at 4 to 6 o’clock on the moon’s image on the APOD site. Notice it’s just a little darker than the rest, vaguely circular with some scattered medium gray spots. Big as it is, it wasn’t completely identified until the 90’s, well after the Apollo missions.