Rupes Recta

Image taken from our Backyard
on the 19th April 2013 with a QHY5v
planetary camera coupled with
 a 127mm Meade Apo refractor

The night before last was a little cold for this time of year but the sky was clear and transparent.

Because the Moon was being lit by the Sun obliquely, I decided to try to find and photograph Rupes Recta a fault which can only be seen when its illuminated from a low angle.

Rupes Recta, also known as the 'Straight Wall', can be seen in my photograph, apparent as an almost vertical line running almost North-South (Centre-Top).

The fault is 114 kilometers long and is situated on the East bank of Mare Nubium.  The fault connects the crater Thebit D to the North with a small mountain to the South.

Although shadow makes the fault appear as a wall or cliff, in reality the fault is marked by a gentle slope of between thirty and forty degrees. From the Earth Rupes Recta is only visible one day after First Quarter or Last Quarter.

The scarp was formed in the Imbrian geological period - between 3.2 and 3.85 billion years ago!

Enlargement of area around
Rupes Recta