Contains:  Solar system body or event
Rupes Recta - The Straight Wall, 


            Bob Gillette

Rupes Recta - The Straight Wall

Acquisition type: Lucky imaging

Imaging telescopes or lenses: Santel MK-91 Mak-Cass 230 mm f/13

Imaging cameras: FLIR/Point Grey Grasshopper 2 GigE

Mounts: Astro-Physics AP 900 GTO

Guiding telescopes or lenses: Hutech Borg 60mm

Guiding cameras: ORION StarShoot AutoGuider

Software: Adobe Photoshop CS4  ·  Topaz Denoise AI  ·  Registax 6  ·  Maxim DL5  ·  Software Bisque TheSky6  ·  FireCapture  ·  AS!2

Filters: Baader IR 685

Accessory: Spike-a Bahtinov Mask  ·  Technical Innovations RoboFocus

Date: Oct. 25, 2020

FPS: 60.00000

Focal length: 3000

Seeing: 3

Transparency: 4

Resolution: 1002x746

Locations: Roughacre Observatory, Ossipee, NH, United States

Data source: Backyard


Rupes Recta – the Straight Wall (strictly speaking, “Straight Cliff), a 110 km linear fault escarpment on the edge of Mare Nubium.

Looks like a steep cliff but it’s actually a fairly gentle slope 300 meters high and 2-3 km wide. Imaging conditions were poor, clouds coming and going, so I could collect only about 2600 frames, of which this image uses 780, but I was determined to capture this feature.

According to a 2013 paper by Amanda Nahm and Richard Schultz, Lyell Collection of the Geological Society, London, Rupes appears to have a “genetic relationship” to the Rima Birt rille, visible here just left of and parallel to the upper half of Rupes. They estimate that regional stress generated both features no earlier than 3.2 billion years, making Rupes probably one of the youngest large-scale normal (stretch-related) faults on the Moon as well as one of the most prominent.

They also estimate its maximum vertical displacement at 400 meters and the depth of the nearly vertical fault plane at 42 km.