Gassendi (114 km.), Is probably one of the oldest craters on the Moon.

It is a magnificent crater, which dominates the north of Mare Humorum. Much of the crater overlaps north of Mare Humorum, where it narrows and the south wall of Gassendi is almost submerged.

The Gassendi floor is a complex of mountains, hills and ditches. The group of three large central mountains, is surrounded by Rimae Gassendi, which cuts most of the crater floor, especially in the east of the central peaks. The most important Rilles (ditches) are from the eastern most central high peak, and leaning to the eastern wall of the crater. Among these grooves are seen two small craters, but notables who are with them. The main grooves Rimae Gassendi cover more than 300 km.

Gassendi is a scientifically interesting site because it offers the Moon sampling possibility of very old rocks in the mountains (the central peak of the crater) and can provide ages for both Humorum impact basin as the very Gassendi crater. However because the crater of land near the peaks is quite rustic, Apollo 17 crew not landed in this region, it would be very difficult to reach the central peaks of Gassendi for sampling. Gassendi was considered as one of three potential sites for the Apollo 17 mission, which eventually touched land in the Taurus Littrow-worth.

The age of Gassendi crater is estimated to be about 3.6 billion years (with a plus or minus 700 million years error).

When observed through spectroscopic analysis to Gassendi crater has a "behavior" very different from any other lunar crater (Mikhail 1979). Studies of high resolution near infrared light (Chevrel and Pinet 1990, 1992) indicated the presence of extrusive volcanic material (which is volcanic material flowing out the surface and then crystallizing) limited to the southern part of floor of Gassendi, which is adjacent to Mare Humorum.

The interpretation of these data suggested that the central part of the crater, including the peak of the complex may have a more nature 'mafic' (which is a rock makeup solidification from the melt that are high in iron and magnesium silicates, such olivine and pyroxene as) with a pyroxene component higher than neighboring plateaus.

Interpretation of the data also suggest that large extrusive volcanism may have occurred in the eastern portion of the floor, which is also indicated by the significant presence of pyroxene, which corresponds to visible volcanic features.

The difference between the western and eastern side of Gassendi due to fractured crater floor can estrar strongly linked to early thermal history of Mare Humorum.

The crater is named after Pierre Gassendi (1592-1655), French philosopher, scientist and mathematician. In 1631, Gassendi became the first person to observe the transit of a planet across the sun, watching the transit of Mercury which Kepler had predicted.

The Gassendi (33 km), is a crater with sharp edges, is superimposed on the north end of Gassendi. A south ridge of this crater, is in Gassendi floor, causing a prominent shadow of the arrow in the picture attached.

Source: ESA / European Space Agency

LUPU VICTOR / Astronomy

Adaptation: Avani Soares