Moon's south pole revealed in 'dramatic' new 3D map

2019-02-28 13:20:02

By David Shiga Video: The latest data on the terrain of the Moon’s south polar region have been used to make this animation, which shows what future astronauts would see during a descent to the rim of Shackleton Crater (Courtesy of NASA) Video: This simulation shows the amount of sunlight falling on the Moon’s south polar region over the course of one (solar) day (Courtesy of NASA) Video: This animation depicts a flyover of the Moon’s south polar region, ending near the 19-km-wide Shackleton Crater (Courtesy of NASA) Earth-based radar observations have produced a detailed 3D map of the Moon’s south polar region, revealing a dramatic and rugged landscape. The map will help NASA assess the site’s potential for setting up a base. NASA plans to return humans to the Moon by 2020 and wants to eventually set up a permanent base there. The Moon’s poles are considered particularly good locations for a base. That’s because frozen water may be present in frigid, permanently shadowed craters at the poles, providing a crucial resource for astronauts. At the same time, some terrain at the poles may be permanently illuminated, providing prime spots to set up solar power stations. Now, scientists have produced the most detailed 3D map yet of the Moon’s south pole. It will allow them to better map out areas of perpetual light and permanent shadow and analyse the terrain to find the safest spots to land. NASA used its 70-metre Goldstone radio dish in the Mojave desert in California, US, to direct a radar signal at the Moon for three 90-minute periods over a span of six months in 2006. The reflected signals were measured by two 34-metre dishes, also in the Mojave desert. The two smaller dishes are separated by 13 kilometres, allowing for the depth perception needed to produce the 3D view, which covers a small area 600 by 400 kilometres across at the south pole. The new map reveals horizontal details as small as 20 metres across – 50 times the resolution of the images returned by the Clementine spacecraft in 1994. The new map shows heights to an accuracy of 5 metres – 30 times better than the resolution of previous maps. “The height variation we’ve seen is actually quite dramatic,” says Scott Hensley of NASA’s Jet Propulsion Laboratory in Pasadena, California, US, who led the observations. “In this small area, you have more topographic variation than there is on the entire land surface of Earth,” Hensley says. The height difference between the highest and lowest points in the patch observed is 12 kilometres. On Earth, the height variation amounts to only 9 kilometres, if one keeps only to land. Some of the craters mapped are up to 4 kilometres deep – large enough to completely contain Earth’s largest volcano, Mauna Loa, Hensley adds. “It’s more dramatic than what we remember from the Apollo missions,” says Doug Cooke, the deputy associate administrator for NASA’s exploration systems mission directorate. “It’s got a peak as high as Mount McKinley at 20,000 feet [6100 metres], it’s got craters that are as deep as four times the depth of the Grand Canyon, all in a small region.” The new view will help NASA locate the areas that spend the most time in sunlight at the lunar south pole, Hensley says. “We’re interested in that, of course, because solar power is going to be one of the primary means of getting power on the surface of the Moon,” he says. Click on the image below right to watch a video of the illumination of the south polar region over one day. It should also help in the hunt for water ice at the Moon’s south pole. The Lunar Prospector and Clementine spacecraft detected large amounts of hydrogen in the surface material at the lunar poles, which could be a sign of water ice. But the situation grew murkier in 2006 when the Arecibo radio telescope failed to detect the signature of ice there. The Arecibo observations looked for the signature of water in the polarisation, or orientation, of the returning radar signals. The Goldstone observations did not include polarisation measurements, so they were not capable of detecting ice. But the new 3D map could help future space probes, like the Lunar Reconnaissance Orbiter set for launch in late 2008, better target their efforts to detect any ice. The map should also help NASA plan for possible human missions to the lunar south pole. Scientists have already used the data to spot a large flat area on the rim of a crater named Shackleton in the region, which could make for a good landing spot (click on the image above right to watch an animation of such a landing). “This type of information is critical for us in understanding what we’re getting into if we choose to land here,” Cooke says. “It will help us to plan out missions with people on the surface [and] how they can manoeuvre and get to different locations. It’s very important from that standpoint.” The new map was unveiled on Wednesday at the 3rd Space Exploration Conference and Exhibit in Denver, Colorado,