Lunar Features — Southwest Quadrant

Abstract

Tycho, at the center of the Moon’s brightest and most extensive system of rays, is the most obvious crater visible on the surface of the full moon, and therefore as good a place as any to start exploring the southwest quadrant. Tycho is a huge walled plain, 90 km (56 miles) in diameter, its walls soaring an impressive 3500 m (12 000 ft) above its floor, capped with peaks 1500 m (5000 ft) high. Wilkins and Moore describe the walls as consisting of a series of straight segments, and indeed this is how they appear, though overall the crater outline is pretty round. The segments were likely produced by differential slumping of the debris blown free from the crater’s center at impact after it piled up to make the inner walls of the crater. Landslips occurred at different times and places around the crater walls, and not in a perfectly smooth circular pattern.