Armstrong is a tiny lunar impact crater located in the southern part of the Mare Tranquillitatis. It lies about 50 kilometers to the northeast of the Apollo 11 landing site. Armstrong is the eastern-most of the row of three craters named in honor of the Apollo 11 crew members. To the north is the Ranger 8 impact site.
This crater was previously identified as Sabine E before being renamed by the IAU.
