WEBVTT FILE 1 00:00:00.000 --> 00:00:01.960 Music 2 00:00:01.960 --> 00:00:06.520 As you watch the Moon over the course of a month, you'll notice that different 3 00:00:06.529 --> 00:00:11.200 features are illuminated by the Sun at different times. However, there are some 4 00:00:11.210 --> 00:00:14.900 parts of the Moon that never see sunlight. These areas are called 5 00:00:14.900 --> 00:00:19.070 permanently shadowed regions, and they appear dark because unlike on the Earth, 6 00:00:19.070 --> 00:00:22.820 the axis of the Moon is nearly perpendicular to the direction of the 7 00:00:22.820 --> 00:00:27.140 Sun's light. The result is that the bottoms of certain craters, like here at 8 00:00:27.140 --> 00:00:31.279 the Moon's south pole, are never pointed toward the Sun, with some remaining dark 9 00:00:31.279 --> 00:00:35.989 for over two billion years. However, thanks to new data from NASA's Lunar 10 00:00:35.989 --> 00:00:39.829 Reconnaissance Orbiter, we can now see into these dark craters in incredible 11 00:00:39.829 --> 00:00:44.539 detail. Seeing the shape of the crater is important, and LRO has used its LOLA 12 00:00:44.539 --> 00:00:48.350 instrument to make the best yet topographical maps of these craters by 13 00:00:48.350 --> 00:00:52.609 reflecting lasers off the lunar surface. This has allowed us to see the shapes of 14 00:00:52.609 --> 00:00:57.319 the craters' interiors from any angle, and by making 3D models, we can light up the 15 00:00:57.319 --> 00:01:01.519 crater floors as if we had a giant flashlight. And although the Sun never 16 00:01:01.519 --> 00:01:05.960 illuminates these craters, other stars still cast a faint light into the 17 00:01:05.960 --> 00:01:11.240 permanent shadows. LRO's LAMP instrument can actually measure this light, giving 18 00:01:11.240 --> 00:01:15.470 us yet another view of this unique region on the Moon. LRO's DIVINER 19 00:01:15.470 --> 00:01:20.540 instrument can also measure temperature, revealing the extreme cold within the 20 00:01:20.540 --> 00:01:26.210 craters. Finally, LRO's LEND instrument can measure the speed of neutrons to 21 00:01:26.210 --> 00:01:30.800 detect elements like hydrogen in the lunar soil. So, while there are some areas 22 00:01:30.800 --> 00:01:35.450 on the Moon that never see the light of day, LRO will keep collecting data so 23 00:01:35.450 --> 00:01:39.200 that we can learn more about them. And as we continue to study the Moon, we'll 24 00:01:39.200 --> 00:01:43.370 improve our understanding of Earth's original satellite, and, pun fully 25 00:01:43.370 --> 00:01:46.360 intended, bring new discoveries to light. 26 00:01:46.360 --> 00:01:48.700 Music 27 00:01:48.700 --> 00:01:57.540 Beep, Beep, Beep