Hipparchus (lunar crater)

lunar crater data


caption=The lunar crater Hipparchus lies in the middle of this image. NASA photo.
latitude=5.5
N_or_S=S
longitude=4.8
E_or_W=E
diameter=150 km
depth=3.3 km
colong=354
eponym=Hipparchus

Hipparchus is the degraded remnant of a lunar crater. It is located to the southeast of Sinus Medii, near the center of the visible Moon. To the south is the prominent crater Albategnius, and to the southwest lies Ptolemaeus, a feature of comparable dimensions to Hipparchus. Horrocks lies entirely within the northeast rim of the crater. Halley is attached to the south rim, and Hind lies to the southeast. To the north-northeast is the bowl-shaped Pickering, and the flooded Saunder is located off the northeast rim.

Hipparchus is where the Moon rocket lands in Tintin's "On a marché sur la Lune" ("Explorers on the Moon").

Description

This feature is an ancient crater that has been subject to considerable modification due to subsequent impacts. The western rim of Hipparchus has been all but worn away from impact erosion, and only low hills and rises in the surface remain to outline the feature. The wall to the east is somewhat more intact, but it too is heavily worn. A pair of deep clefts lie in the western wall. These parallel a sets of scars running through the south-central highlands.

The crater floor has been partially resurfaced by basaltic lava flow. The southwest part of the floor, however, is slightly raised and much more rugged than the remainder. A few small rises and the raised partial rim of a flooded crater are all that remain of a central massif.

Gaps in the northwest rim of Hipparchus form valleys that connect with the mare to the northwest. A rille named Rima Réaumur runs from this site to the outer wall of Réaumur.

atellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Hipparchus.

References

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