»Rupes Recta« is the name for a long line, which is visible on the Moon’s surface. The name derives from Latin and means »straight fault«, but due to its prominent shape, it is also called »Sword of the Moon«.
Rupes Recta is located at the edge of the lunar mare Mare Nubium and is one of the best known escarpments of the Moon. It is more than 60 miles long, with a width of 1–2 miles and a height of around 800 feet.
This formation is not a steep slope (as originally assumed by scientists in the early days, and hence the term »straight wall« was used), because the specified dimensions indicate a slope of only about 10°. Nevertheless, it is very remarkable, because of its length and straight shape.
You are even able to observe Rupes Recta with a simple telescope at the time of the half moon, because during this period the incident sunlight casts a shadow or creates a light-refracting edge near the terminator.
Located far away, this landscape always remains enigmatic, even if one day many of us might walk on the Moon.