The Moon's permanently shadowed regions, or PSRs, are places on the Moon that haven't seen the Sun in millions, or even billions, of years. The Earth's tilted axis allows sunlight to fall everywhere on its surface, even at the poles, for at least part of the year. But the Moon's tilt relative to the Sun is only 1.6°, not enough to get sunlight into some deep craters near the lunar north and south poles. PSRs are therefore some of the coldest, darkest places in the solar system.Because of that, PSRs are expected to be excellent traps for volatiles, chemicals that would normally vaporize and escape into space, and this includes water. Lunar Reconnaissance Orbiter (LRO) includes several instruments designed to peer into the PSR darkness and measure temperature, reflectivity, and neutron absorption, all of which are clues to what chemicals might be hiding there. This animation shows where the PSRs are and in what ways LRO can see inside them. || || 4043 || LRO Peers into Permanent Shadows || The Moon's permanently shadowed regions, or PSRs, are places on the Moon that haven't seen the Sun in millions, or even billions, of years. The Earth's tilted axis allows sunlight to fall everywhere on its surface, even at the poles, for at least part of the year. But the Moon's tilt relative to the Sun is only 1.6°, not enough to get sunlight into some deep craters near the lunar north and south poles. PSRs are therefore some of the coldest, darkest places in the solar system.Because of that, PSRs are expected to be excellent traps for volatiles, chemicals that would normally vaporize and escape into space, and this includes water. Lunar Reconnaissance Orbiter (LRO) includes several instruments designed to peer into the PSR darkness and measure temperature, reflectivity, and neutron absorption, all of which are clues to what chemicals might be hiding there. This animation shows where the PSRs are and in what ways LRO can see inside them. || Beginning with a full-frame Moon, the camera flies to the lunar south pole and shows areas of permanent shadow. Realistic shadows evolve through several months. || shot1_on.0420.jpg (1920x1080) [444.6 KB] || shot1_on.0420_web.png (320x180) [82.1 KB] || shot1_on.0420_thm.png (80x40) [5.3 KB] || shot1_on_1080p30.mov (1920x1080) [55.0 MB] || shot1_on_1080p30.mp4 (1920x1080) [19.1 MB] || shot1_on_720p30.mov (1280x720) [31.7 MB] || shot1_on_720p30.mp4 (1280x720) [10.1 MB] || shot1_on (1920x1080) [65536 Item(s)] || shot1_on_1080p30.webmhd.webm (960x540) [8.2 MB] || shot1_on_360p30.mov (640x360) [12.3 MB] || shot1_on_360p30.mp4 (640x360) [3.8 MB] || The same push-in to the south pole as the previous, without the permanent shadow overlay. || shot1_off.0420.jpg (1920x1080) [356.4 KB] || shot1_off.0420_web.png (320x180) [68.9 KB] || shot1_off_1080p30.mov (1920x1080) [40.1 MB] || shot1_off_1080p30.mp4 (1920x1080) [15.9 MB] || shot1_off_720p30.mov (1280x720) [23.5 MB] || shot1_off_720p30.mp4 (1280x720) [8.0 MB] || shot1_off (1920x1080) [65536 Item(s)] || shot1_off_1080p30.webmhd.webm (960x540) [8.2 MB] || shot1_off_360p30.mov (640x360) [8.6 MB] || shot1_off_360p30.mp4 (640x360) [2.9 MB] || Demonstration of the differing obliquity (tilt) of the Earth and Moon. Zooms quickly on the Moon as it emerges from behind the Earth. || tilt.0450.jpg (1920x1080) [67.9 KB] || tilt.0450_web.png (320x180) [15.6 KB] || tilt_1080p30.mov (1920x1080) [7.3 MB] || tilt_1080p30.mp4 (1920x1080) [2.8 MB] || tilt_720p30.mov (1280x720) [4.4 MB] || tilt_720p30.mp4 (1280x720) [1.4 MB] || tilt (1920x1080) [16384 Item(s)] || tilt_1080p30.webmhd.webm (960x540) [1.5 MB] || tilt_360p30.mov (640x360) [1.5 MB] || tilt_360p30.mp4 (640x360) [442.6 KB] || A close flyover of south pole terrain. Elevation contours light up, and as we arrive at Shackleton crater, elevation color coding lights up inside it and in other permanently shadowed regions. Finally, the view pans up into the sky, revealing a rich starfield. || closeup.0550.jpg (1920x1080) [532.0 KB] || closeup.0550_web.png (320x180) [97.3 KB] || closeup_1080p30.mov (1920x1080) [62.1 MB] || closeup_1080p30.mp4 (1920x1080) [15.2 MB] || closeup_720p30.mov (1280x720) [34.3 MB] || closeup_720p30.mp4 (1280x720) [6.9 MB] || closeup (1920x1080) [32768 Item(s)] || closeup_1080p30.webmhd.webm (960x540) [6.0 MB] || closeup_360p30.mov (640x360) [12.6 MB] || closeup_360p30.mp4 (640x360) [2.6 MB] || Three different datasets are overlaid on the south pole. For each, the full dataset fades to a version masked by the permanent shadow map. The datasets are from LAMP (lyman alpha albedo), Diviner (daytime temperature), and LEND (hydrogen). || poledata.0415.jpg (1920x1080) [411.1 KB] || poledata.0415_web.png (320x180) [84.6 KB] || poledata_1080p30.mov (1920x1080) [56.3 MB] || poledata_1080p30.mp4 (1920x1080) [14.5 MB] || poledata_720p30.mov (1280x720) [31.5 MB] || poledata_720p30.mp4 (1280x720) [7.7 MB] || poledata (1920x1080) [32768 Item(s)] || poledata_1080p30.webmhd.webm (960x540) [5.3 MB] || poledata_360p30.mov (640x360) [12.1 MB] || poledata_360p30.mp4 (640x360) [3.1 MB] || Planets & Moons || Diviner Lunar Radiometer Experiment (DLRE) || Elevation data || HDTV || LAMP || Laser Altimeter || LEND || LOLA || LRO || Lunar || Lunar Elevation Map || Lunar Reconnaissance Orbiter || Lunar Surface || Lunar Surface Temperature || Lunar Topography || Moon || Neutron || Clementine || LRO (Lunar Reconnaissance Orbiter) || LRO - Animations || The Moon || [LRO: Diviner] || 750-nm Basemap [Clementine: UVVIS Camera] || DEM (Digital Elevation Map) [LRO: LOLA] || Neutrons [LRO: LEND] || LRO LAMP (Lyman alpha and UV) [LRO: LAMP] || Ernie Wright (USRA) as Animator || Dan Gallagher (USRA) as Producer || John Keller (NASA/GSFC) as Scientist ||