BRIEF DESCRIPTION
The Mare Humorum basin and an interesting walled plain Gassendi, which resembles a diamond ring, are among the most prominent features of the south-western quadrant of the near-side of the Moon. The system of concentric wrinkle ridges in M. Humorum and the neighboring rilles Rimae Hippalus are good objects for telescopic observation.  Refer to your copy of the Antonin Rukl lunar atlas chart, page 131.

EARTH-BASED TELESCOPIC IMAGES: 
Consolidated Lunar Atlas
Image - Gassendi (Sussenbach)
Image - Gassendi (Cristian Fattinnanzi, 20" f6 newton at f:30 with a Vesta pro phillips webcam)
Image - Gassendi and region ("Marco Falorni" Planetary Observatory)
Image - Gassendi region (Dittmer)
Image - Gassendi (Therin)
Image - Gassendi (Massey)
Image - Mare Humorum and Gassendi (QHO)
Image - Mare Humorum & Gassendi (ESO, phot-02d-99-preview.jpg)

LUNAR ORBITER IMAGES:
Digital Orbiter Photographic Atlas of the Moon: http://cass.jsc.nasa.gov/research/lunar_orbiter/
Agatharchides, 49 km
Doppelmayer, 64 km
Gassendi, 110  km
http://cass.jsc.nasa.gov/pub/expmoon/orbiter/5lo178m.gif
Hippalus, 58 km
Mare Humorum, SE portion
Kelvin, Promontorium
Kelvin, Rupes
Loewy,  22x26 km
Puiseux, 25 km

APOLLO IMAGES:
Apollo Image Atlas: http://cass.jsc.nasa.gov/research/apollo/index.html
Gassendi, AS16-120-19295(H)
http://www.astrosurf.com/lunascan/as16-120-19295.jpg
Mare Humorum
http://cass.jsc.nasa.gov/pub/expmoon/Apollo17/A17metric0602.gif

CLEMENTINE IMAGES:
http://www.astrosurf.com/lunascan/lud0120h.htm

RESEARCH UPDATES:
AS16-120-19295(H) - Awesome close-up of Gassendi (SP-362,175)
Gassendi (Lunascan)
LTPs in Gassendi (various)
Gassendi & Other Moon Anomalies from Clementine (anomalous-images.com)
Mare Humorum - Lunar Orbiter:  Impact Basin Geology (NASA)
USAF Lunar Chart - Mare Humorum (1966)