Shackleton is an impact crater that lies at the south pole of the Moon. The peaks along the crater's rim are exposed to almost continual sunlight, while the interior is perpetually in shadow. The low-temperature interior of this crater functions as a cold trap that may capture and freeze volatiles shed during comet impacts on the Moon. Measurements by the Lunar Prospector spacecraft showed higher than normal amounts of hydrogen within the crater, which may indicate the presence of water ice. The crater is named after Ernest Shackleton, a noted Anglo-Irish explorer of the Antarctic.
The rotational axis of the Moon lies within Shackleton, only a few kilometers from its center. The crater is 21 km in diameter and 4.2 km deep. From the Earth, is viewed edge-on in a region of rough, cratered terrain. It is located within the South Pole-Aitken basin on a massif.
Because the orbit of the Moon is tilted only 5° from the......