Alden (crater)

Alden is a large impact crater located in the Mare Australe quadrangle of Mars, at 138.1° E and 55.3° S. It measures 109 kilometers in diameter and was named after Harold Alden, an American astronomer.

The crater displays features indicative of past glacial activity, including possible glacial moraines and patterned ground. Its central peak is complex and exhibits evidence of modification, possibly due to erosion or impact-related processes. The crater floor shows evidence of layering, suggesting sedimentary deposition.

Alden is notable for its relatively well-preserved state, making it a valuable site for studying Martian geology and potential past environments. It has been the subject of various studies utilizing data from Mars orbiters such as Mars Reconnaissance Orbiter (MRO) and Mars Express.