Designing a mission to the Moon requires countless decisions, including where to go. NASA, private companies and space agencies from other nations have targeted Shackleton Crater, near the Moon's South Pole.

WHY THE SOUTH POLE?
The South Pole region has water-ice probably left over from comet impacts. It also has sunlight on crater rims, along with plenty of lunar regolith--rocks and dirt--that could help humans "live off the land" on the Moon someday.

MOON'S SOUTH POLE

Aitken Basin-South Pole NASA/GSFC/Arizona State University

Shackleton Crater, a potential site for the next manned lunar mission, is a medium-sized crater near the lunar South Pole. It also lies within the Moon's largest crater, the South Pole-Aitken Basin. This massive crater is as wide as the distance between London and Moscow.

NASA

VITAL STATS: SHACKLETON CRATER

• SIZE: 12 miles wide (20 kilometers)
• AVERAGE TEMPERATURE: -100 F (-73 C), at crater rim, average temperature of the soil is colder than all but the coldest days on Earth in Antarctica
• DEPTH: 2.5 miles (4 km), a bit deeper than Japan's Mt. Fuji is high
• NAMED AFTER: Ernest Shackleton (1874-1922), the famed British Antarctic explorer

RESOURCE: WATER

The dry Moon has water--just a bit, and it's mostly at the Poles. In the basins of permanently shadowed craters such as Shackleton, where the Sun never shines and where it is really, really cold, there is shallowly buried water-ice that has probably been there for billions of years.

While the first group of returning astronauts will probably bring all the water they need for drinking, future astronauts would likely need to process lunar soil for the water they need. Even recycling much of the water they use within their spacecraft--including their own sweat and urine--wouldn't be enough.