NASA says moon south pole more rugged than thought

WASHINGTON (Reuters) - The moon's south pole region, a possible future landing site for human or robotic lunar missions, is far more rugged than had been thought, with towering peaks and deep craters, NASA said on Wednesday.

Using an Earth-based radar system in California's Mojave Desert, the U.S. space agency collected the most accurate, highest-resolution terrain mapping data to date on the moon's south pole.

NASA looked at an area around Shackleton Crater, with some terrain in perpetual darkness and other areas almost always sunlit. Scientists previously have gotten images of the area, but never in such detail, NASA said.

The Shackleton Crater rim area is a landing site candidate for a future crewed mission to the moon, NASA said. There have been previous indications water ice might exist in darkened areas of the crater, although that remains controversial.

The region has a peak towering 3.8 miles -- rivaling North America's tallest mountain, Mount McKinley in Alaska -- and craters 2.5 miles deep, NASA said. The scientists noted that the largest volcano on Earth -- Mauna Loa in Hawaii -- would fit easily inside these depths.

"It continues to be an area of high interest for future human landings. And this type of information is critical for us in understanding what we're getting into if we choose to land here," said Doug Cooke of NASA's Exploration Systems Mission Directorate.

Asked if the rugged terrain might give NASA pause, Cooke told reporters, "I don't think it's less attractive."

"It really calls on us to rise to the challenge of getting there, rather than having engineering constraints limit us," added NASA lunar program scientist Kelly Snook.

Cooke emphasized the importance of the possible presence of frozen ice in the region to a lunar mission.

"Having water ice gives us a source of water and gives us a source of hydrogen and oxygen, which can be made into fuel. One of the things we're interested in doing as we explore the moon and eventually Mars is to learn how to take advantage of the resources that are there to enhance the missions (and) reduce the amount of resupply and logistics from Earth," Cooke said.

Scott Hensley of the Lunar Image Team at JPL said the data could be valuable in choosing the best sites both for robotic operations on the moon in addition to human missions.

Scientists at NASA's Jet Propulsion Laboratory in Pasadena, California, obtained the data using the facility's Goldstone Solar System Radar.

Three times during a six-month period in 2006, the scientists targeted the region using Goldstone's 230-foot (70-meter) radar dish, sending a 500-kilowatt strong, 90-minute long radar stream 231,800 miles to the moon.

The radar bounced off lunar terrain over an area measuring about 400 miles by 250 miles and the signals were reflected back to two antennas on Earth in about 2 1/2 seconds, NASA said.

(Editing by Maggie Fox and Doina Chiacu)