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


Hipparchus (90 miles) is a battered and worn down formation. The highest walls are on the southwest rim and may reach 1½ miles above the floor. The northwestern rim is very low and missing in some places. The very large flat floor is full of detail as the sun illuminates this region at first quarter.

Horrocks (18 miles) is a very prominent crater on the northeastern floor of Hipparchus. It is a fine crater in its own right. The walls are terraced and rise almost 2 miles above a small central peak.

Halley (22 miles) is about 1½ miles deep. There is a tiny central peak, really just a hill that is visible as the shadow of the eastern wall moves off of it at sunrise.

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Louisville Astronomical SocietyLouisvilleUSA

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