Geological Chronicle
Located along the Moon's northern limb on the eastern side of the north pole, Nansen is an old impact crater spanning 116.9 kilometers in diameter. Viewed from the edge from Earth during favorable librations, the formation can be located by finding the crater Baillaud and following the surface toward the limb. Observing fine topographic detail requires a vantage point from orbit.
The crater dates to the Nectarian epoch of the lunar geologic timescale. Heavy erosion from minor impacts has left an irregular outer wall marked by multiple small craters and indentations. A small crater lies across Nansen's northern rim, a similar formation rests along the inner southern wall, and a merged chain of tiny craters crosses the eastern rim.
The interior floor of Nansen is more hummocky and irregular in the northern half, whereas the southern part is relatively level. A small, bowl-shaped crater lies in the southeastern section of the floor, accompanied by many tiny craterlets across the interior and along the inner walls. The feature is named for Norwegian explorer Fridtjof Nansen.