1 00:00:00,900 --> 00:00:04,466 On April 8th, 2024, portions of the United States 2 00:00:04,466 --> 00:00:07,733 will get to enjoy the sight of a total solar eclipse. 3 00:00:07,733 --> 00:00:11,633 The last time this took place was back in August of 2017. 4 00:00:11,633 --> 00:00:15,233 So, this is a good time to refresh our memory as to what's going to happen, 5 00:00:15,233 --> 00:00:16,433 why it occurs, 6 00:00:16,433 --> 00:00:19,733 and let you know where you can watch the show in the sky. 7 00:00:19,733 --> 00:00:23,366 A solar eclipse occurs when the Moon moves between the Earth and the Sun, 8 00:00:23,366 --> 00:00:26,566 blocks the Sun's light and casts a shadow on the Earth. 9 00:00:26,566 --> 00:00:27,866 When the Moon completely covers 10 00:00:27,866 --> 00:00:31,800 the bright disk of the Sun, that's a total solar eclipse. 11 00:00:31,800 --> 00:00:35,566 This differs from a lunar eclipse, where the Moon moves behind the Earth, 12 00:00:35,566 --> 00:00:38,633 so it's now the Earth blocking the Sun's light on the Moon, 13 00:00:38,633 --> 00:00:41,100 creating a shadow on it with a red tint. 14 00:00:41,100 --> 00:00:42,333 To remember the difference, 15 00:00:42,333 --> 00:00:44,733 just remember what object gets darker. 16 00:00:44,733 --> 00:00:46,866 With a solar eclipse, it's the Sun, 17 00:00:46,866 --> 00:00:49,566 and during a lunar eclipse, it's the Moon. 18 00:00:49,566 --> 00:00:51,933 Because the Moon's shadow is relatively small, 19 00:00:51,933 --> 00:00:55,200 a total solar eclipse is a pretty rare event to see. 20 00:00:55,200 --> 00:00:57,766 In order to do so, you have to be on the sunny side 21 00:00:57,766 --> 00:01:00,800 of the planet and within the path of the Moon's shadow. 22 00:01:00,800 --> 00:01:04,533 And that path is affected by the Earth's rotation, Moon's orbit 23 00:01:04,533 --> 00:01:07,333 and where they are in their orbit around the Sun. 24 00:01:07,333 --> 00:01:11,700 There are a lot of moving parts that go into creating this incredible sight. 25 00:01:11,700 --> 00:01:16,533 And speaking of parts, during a solar eclipse, the Moon is actually casting a shadow 26 00:01:16,533 --> 00:01:20,033 consisting of two parts: The umbra and penumbra. 27 00:01:20,033 --> 00:01:22,266 The Moon's umbra is the part of the Moon's shadow 28 00:01:22,266 --> 00:01:25,033 where the entire sun is blocked by the Moon. 29 00:01:25,033 --> 00:01:30,166 In space, it's a cone extending about 232,000 miles behind the Moon. 30 00:01:30,166 --> 00:01:32,700 It's when the small end of this cone hits the Earth 31 00:01:32,700 --> 00:01:35,666 that a total solar eclipse can be seen. 32 00:01:35,666 --> 00:01:39,200 Those factors are why only a limited number of locations on Earth 33 00:01:39,200 --> 00:01:40,800 get to actually see it. 34 00:01:40,800 --> 00:01:45,833 So, if you find your area in the path of totality this year, treasure the sight - 35 00:01:45,833 --> 00:01:49,533 because on average, that same spot on Earth won't see another 36 00:01:49,533 --> 00:01:53,366 total solar eclipse for 375 years. 37 00:01:53,366 --> 00:01:57,533 The area around Carbondale, Illinois, however, has hit the cosmic jackpot - 38 00:01:57,533 --> 00:02:02,166 getting to experience this year's eclipse, as well as the one from 2017. 39 00:02:02,166 --> 00:02:05,366 But their next view of a total solar eclipse 40 00:02:05,366 --> 00:02:09,733 won't happen until the year 2343. 41 00:02:09,733 --> 00:02:13,166 When you check out an eclipse map that depicts the path of totality, 42 00:02:13,166 --> 00:02:14,600 keep this in mind: 43 00:02:14,600 --> 00:02:17,833 While many maps will show a circle representing the Moon's shadow, 44 00:02:17,833 --> 00:02:19,266 the true shape of the umbra 45 00:02:19,266 --> 00:02:23,333 is more like an irregular polygon with slightly curved edges. 46 00:02:23,333 --> 00:02:26,700 This is due to the fact that the Moon isn't a smooth sphere. 47 00:02:26,700 --> 00:02:30,133 It has mountains, valleys and craters on its surface - 48 00:02:30,133 --> 00:02:34,533 all of which affect the passing sunlight and shape of the resulting shadow. 49 00:02:34,533 --> 00:02:37,233 NASA's Lunar Reconnaissance Orbiter spacecraft, 50 00:02:37,233 --> 00:02:41,066 which has been orbiting the Moon since 2009, has provided scientists 51 00:02:41,066 --> 00:02:45,300 with incredibly detailed photographs, terrain maps, and other sets of data 52 00:02:45,300 --> 00:02:48,933 that have allowed us to better understand the shape of the Moon's surface. 53 00:02:48,933 --> 00:02:53,700 This, in turn, has given us the ability to create more finely detailed maps 54 00:02:53,700 --> 00:02:59,166 depicting which specific areas on Earth lie within the solar eclipse’s path of totality. 55 00:03:00,266 --> 00:03:02,366 Regions outside the narrow path, 56 00:03:02,366 --> 00:03:03,800 depending on their distance from it, 57 00:03:03,800 --> 00:03:07,433 will get to witness a partial eclipse to varying degrees. 58 00:03:07,433 --> 00:03:12,866 As you can see, the penumbra shadow passes over almost all of North and Central America, 59 00:03:12,866 --> 00:03:16,900 as well as Greenland, Iceland and the Western British Isles. 60 00:03:16,900 --> 00:03:21,400 This 2024 total solar eclipse is therefore giving millions of people 61 00:03:21,400 --> 00:03:24,833 the opportunity to share in this rare and dynamic interaction 62 00:03:24,833 --> 00:03:27,766 between our Earth, Sun and Moon.