This waning gibbous Moon reveals the complex distribution of lunar minerals through subtle variations in color and reflectivity. Iron-rich basalts in the maria appear in muted bluish tones, while highland regions rich in anorthosite show warmer hues. At 87.9 percent illumination, the grazing sunlight deepens the shadows along the terminator, highlighting the rugged topography of craters, ridges, and ancient lava plains that formed over billions of years. The phase also enhances the visibility of ejecta patterns around prominent impact structures.

Captured from Valdemorillo in Spain, the crisp seeing conditions help bring out delicate tonal differences that are often lost under harsher lighting. This mineral color processing accentuates the compositional diversity of the lunar surface without exaggeration, providing a scientifically meaningful view of how the Moon's crust formed and evolved. It offers a clear look at the relationship between geology, illumination, and reflectivity across the lunar landscape.

Image Description and Details :

Rupes Recta is a linear fault on the Moon, in the southeastern part of the Mare Nubium. The name is Latin for straight cliff, although it is more commonly called the Straight Wall. This is the most well-known escarpment on the Moon, and is a popular target for amateur astronomers.

When the sun illuminates the feature at an oblique angle at about day 8 of the Moon's orbit, the Rupes Recta casts a wide shadow that gives it the appearance of a steep cliff. The fault has a length of 110 km, a typical width of 2–3 km, and a height of 240–300 m. Thus although it appears to be a vertical cliff in the lunar surface, in actuality the grade of the slope is relatively shallow.

To the west of this escarpment is the crater Birt, which is about 17 km in diameter. The Birt Rille is a slightly curved ~50 km long channel that starts and ends in a pit.

Telescope: Clestron 9.25 f/10

Reducer/corrector: No reducer

Filter: Baader UV-IR cut

Mount: Orion Atlas EQG

Camera: DMK 23U618

Exposure: 2000 frames @ 60fps x 2 images mosaic

Procesing: Autostakkert + Registax + PixInsight

Copyright: Astronomica.es - Jaime Fernández