Schiller-Zucchius Basin

This basin has received the unofficial designation 'Schiller Annular Plain' among lunar observers.

The basin has a clear but eroded outer rim and a partial inner ring.

Also at the center is a mass concentration (mascon), or gravitational high.

The mascon was first identified by Doppler tracking of the Lunar Prospector spacecraft.

[3] The existence of the mascon was confirmed by the GRAIL spacecraft.