• Don SpainEmail author
Part of the Astronomer's Pocket Field Guide book series (ASTROPOC)


Cleomedes (76 miles wide) has highs walls that rise to over 2½ miles in places. The floor is flat and lava filled. There is a small off-center peak that is less than 1 mile high. There are two craters on the floor that are easy to see even in small instruments. While not visible on the photo image there is a cleft on the northern floor that is relatively easy in my 4 inch refractor under grazing sunlight and very easy in the 6 inch. Look for this fascinating formation 3 days after new Moon.

Thalles (27 miles wide) is a crater intruding onto the northwest rim of Cleomedes. Its steep walls rise to almost 2 miles above the floor. There is no central peak, but the floor is rough and has several hills scattered about. It is worth your time to investigate this formation.

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Louisville Astronomical SocietyLouisvilleUSA

Personalised recommendations