Gauss is the big crater near Mare Crisium. It is visible one day after Full Moon, because this is the exact moment for its best shadow projection. Berosus and Hahn are the two smaller craters near Gauss. It is visible a tiny central peak inside Hahn crater. And inside Gauss we can barely spot a shadow that Gauss B casts. Gauss B is a small crater to be guessed in Gauss.