I am assuming you are referring to the craters in the moon. For thousands and thousands of years, asteroids have been hitting the moon's surface and creating craters. Those craters cast shadows as they do not let light inside of them when the Sun is at an angle, therefore creating "dark marks" on the moon.
The Moon Is dark because the sun light reflects on it so when the sun"s light does not hit the moon it is going to be a dark moon
Dark is the Moon has 704 pages.
The moon is not dark all the time. It is dark in a phase called a "new moon." But it only temporarily lasts.
When the moon appears completely dark it is called a new moon.
craters
dark side of the moon
The Dark Cry of the Moon was created in 1986.
Dark is the Moon was created on 2001-05-03.
Dark Moon Rising was created in 2009.
Dark Moon Digest was created in 2010.
there is no dark moon city
how to get dark marks off your skins