WEBVTT FILE 1 00:00:00.050 --> 00:00:03.070 [slate] 2 00:00:03.070 --> 00:00:06.090 [slate] 3 00:00:06.090 --> 00:00:09.120 Text on screen: What will we experience on August 21? 4 00:00:09.120 --> 00:00:12.180 5 00:00:12.180 --> 00:00:15.290 We are so excited for August 21. 6 00:00:15.290 --> 00:00:18.420 What is going to happen is the moon is going to cross 7 00:00:18.420 --> 00:00:21.630 in between the sun and the Earth and we're going to be treated 8 00:00:21.630 --> 00:00:24.810 to a spectacular show as that shadow goes across the 9 00:00:24.810 --> 00:00:27.860 Earth. Everywhere in North America, Central America 10 00:00:27.860 --> 00:00:30.940 and even bits of South America will get to see some 11 00:00:30.940 --> 00:00:34.070 portion of the eclipse - either partial or total. 12 00:00:34.070 --> 00:00:37.260 If you're in the path of totality that's going to be 13 00:00:37.260 --> 00:00:40.440 especially amazing because what happens is the moon will totally 14 00:00:40.440 --> 00:00:43.620 block out the main body of the sun and you'll get to 15 00:00:43.620 --> 00:00:46.710 see the sun's atmosphere, the solar corona, around the moon. 16 00:00:46.710 --> 00:00:49.740 And it's just going to be amazing. 17 00:00:49.740 --> 00:00:52.770 Text on screen: We've been told never to look directly at the sun (even with sunglasses!). 18 00:00:52.770 --> 00:00:55.970 Text on screen cont.: How can we enjoy this eclipse safely? 19 00:00:55.970 --> 00:00:59.040 That's correct, never look directly at the 20 00:00:59.040 --> 00:01:02.210 sun even with sunglasses on. What you want are 21 00:01:02.210 --> 00:01:05.380 safety eclipse glasses like these. And you can check to 22 00:01:05.380 --> 00:01:08.470 make sure that your eclipse glasses really are safety 23 00:01:08.470 --> 00:01:11.680 eclipse glasses by going to our webpage 24 00:01:11.680 --> 00:01:14.740 eclipse2017.nasa.gov. And on that webpage 25 00:01:14.740 --> 00:01:17.820 we have information of how to check. So, for example you want 26 00:01:17.820 --> 00:01:20.930 to look for an ISO number, cross check that 27 00:01:20.930 --> 00:01:24.120 with what we have on our webpage, and a manufacturer - again, cross check 28 00:01:24.120 --> 00:01:27.310 that with our webpage. During totality, 29 00:01:27.310 --> 00:01:30.360 if you are in that path you can take off your glasses and look 30 00:01:30.360 --> 00:01:33.420 directly at the sun during those couple of minutes. 31 00:01:33.420 --> 00:01:36.510 The other thing you can do is indirectly view the eclipse. 32 00:01:36.510 --> 00:01:39.620 So you can do that by creating a pinhole projection. 33 00:01:39.620 --> 00:01:42.640 You can do that with your hands and create a little pinhole with your fingers there. 34 00:01:42.640 --> 00:01:45.820 You want to stand with the sun at your back. Let 35 00:01:45.820 --> 00:01:48.930 the sun shine through your pinhole and then 36 00:01:48.930 --> 00:01:52.130 the image of the sun and the moon taking a bite out of the sun 37 00:01:52.130 --> 00:01:55.220 will be projected down on the ground in front of 38 00:01:55.220 --> 00:01:58.240 you. 39 00:01:58.240 --> 00:02:01.330 Text on screen: For those in the path of totality - when is it safe to finally take off our solar glasses? 40 00:02:01.330 --> 00:02:04.390 You can take 41 00:02:04.390 --> 00:02:07.480 off your solar glasses when you don't see anything 42 00:02:07.480 --> 00:02:10.590 any longer. That means that the moon has 43 00:02:10.590 --> 00:02:13.750 blocked out the main body of the sun at the atmosphere around it 44 00:02:13.750 --> 00:02:16.950 is now visible. Then, as soon as you start to see 45 00:02:16.950 --> 00:02:20.130 the sun peeking around the moon again you need to put those 46 00:02:20.130 --> 00:02:23.140 glasses right back on. 47 00:02:23.140 --> 00:02:26.170 Text on screen: We're not in the path of totality - what interesting things should we lookout for? 48 00:02:26.170 --> 00:02:29.210 So if you're 49 00:02:29.210 --> 00:02:32.280 not in the path of totality and you're going to get a 50 00:02:32.280 --> 00:02:35.380 partial eclipse, that is still really amazing. What's going to happen is 51 00:02:35.380 --> 00:02:38.540 the moon is going to go across the sun and take a 52 00:02:38.540 --> 00:02:41.720 bite out of the sun, creating crescent shaped 53 00:02:41.720 --> 00:02:44.890 shadows and uh - you'll be able to see those with 54 00:02:44.890 --> 00:02:47.940 a pinhole projector. You can also see those 55 00:02:47.940 --> 00:02:51.010 even if you stand in front of a tree. The shadow as 56 00:02:51.010 --> 00:02:54.130 it goes through the tree - the tree acts like a pinhole projector - 57 00:02:54.130 --> 00:02:57.300 you'll get images of the 58 00:02:57.300 --> 00:03:00.490 moon going across the sun in the shadow 59 00:03:00.490 --> 00:03:03.670 of tree and you'll be able to see that. 60 00:03:03.670 --> 00:03:06.690 Text on screen: Why are you excited for this eclipse? 61 00:03:06.690 --> 00:03:09.850 62 00:03:09.850 --> 00:03:13.020 I am so excited about this eclipse because I 63 00:03:13.020 --> 00:03:16.220 study the solar corona. The solar corona is the part 64 00:03:16.220 --> 00:03:19.270 of the sun that we get to see during a total solar 65 00:03:19.270 --> 00:03:22.350 eclipse. It is the atmosphere of the sun and it's 66 00:03:22.350 --> 00:03:25.460 much less bright than the photosphere - the main body of the sun. 67 00:03:25.460 --> 00:03:28.620 So we usually don't get to see it. I get to 68 00:03:28.620 --> 00:03:31.790 study it with a NASA spacecraft that watches the sun all the 69 00:03:31.790 --> 00:03:34.990 time. But this total solar eclipse, getting to see it in person 70 00:03:34.990 --> 00:03:38.080 and getting to see it in this particular way, is so 71 00:03:38.080 --> 00:03:41.190 exciting to me. 72 00:03:41.190 --> 00:03:44.220 Text on screen: How can we watch the eclipse if the weather isn't on our side on August 21? 73 00:03:44.220 --> 00:03:47.290 74 00:03:47.290 --> 00:03:50.380 nasa.gov/eclipselive 75 00:03:50.380 --> 00:03:53.520 is doing live coverage of the 76 00:03:53.520 --> 00:03:56.720 eclipse - of the path of totality. We have stations 77 00:03:56.720 --> 00:03:59.910 all across the country watching the total solar 78 00:03:59.910 --> 00:04:02.980 eclipse, and we have airplane coverage of 79 00:04:02.980 --> 00:04:06.070 the total solar eclipse. So, whoever gets 80 00:04:06.070 --> 00:04:09.210 to see the eclipse, we will be covering and we'll have 81 00:04:09.210 --> 00:04:12.400 coverage of that. So if you're in the partial phases 82 00:04:12.400 --> 00:04:15.590 of the eclipse or if it was clouded out in your area, check us 83 00:04:15.590 --> 00:04:18.620 out and watch our live coverage of the eclipse. 84 00:04:18.620 --> 00:04:21.640 Text on screen: Why does an eclipse only last for a few minutes? 85 00:04:21.640 --> 00:04:24.840 86 00:04:24.840 --> 00:04:27.860 An eclipse 87 00:04:27.860 --> 00:04:31.060 only lasts for a couple of minutes because of the precise geometry. 88 00:04:31.060 --> 00:04:34.260 We have to get this perfect geometry - this perfect lineup 89 00:04:34.260 --> 00:04:37.330 between the sun, the moon and the Earth. And to get that 90 00:04:37.330 --> 00:04:40.470 to line up just exactly perfect, the shadow 91 00:04:40.470 --> 00:04:43.610 at a given place on the Earth only lasts a 92 00:04:43.610 --> 00:04:46.720 couple of minutes. 93 00:04:46.720 --> 00:04:49.760 Text on screen: What happens to Earth during the eclipse? 94 00:04:49.760 --> 00:04:52.960 95 00:04:52.960 --> 00:04:56.150 As the eclipse happens, it's effectively 96 00:04:56.150 --> 00:04:59.230 turning into night in just a small location 97 00:04:59.230 --> 00:05:02.340 on the Earth for just a brief period of time. 98 00:05:02.340 --> 00:05:05.360 And that's really strange. The atmosphere is 99 00:05:05.360 --> 00:05:08.560 going to respond and become cooler. 100 00:05:08.560 --> 00:05:11.750 The cloud coverage could change. The ionosphere 101 00:05:11.750 --> 00:05:14.800 could change. And we have um an App called Globe 102 00:05:14.800 --> 00:05:17.870 Observer App and we are encouraging citizen scientists to 103 00:05:17.870 --> 00:05:20.970 tell us what is going on - what they are observing 104 00:05:20.970 --> 00:05:24.130 as the eclipse is happening. So if you have a thermometer 105 00:05:24.130 --> 00:05:27.330 and get the Globe Observer App on your phone then 106 00:05:27.330 --> 00:05:30.520 you too can be a citizen scientist and help NASA 107 00:05:30.520 --> 00:05:33.580 collect data on how the Earth is responding 108 00:05:33.580 --> 00:05:36.670 to the eclipse. 109 00:05:36.670 --> 00:05:39.870 Text on screen: If you were looking back at Earth during the eclipse what would you see? 110 00:05:39.870 --> 00:05:43.010 111 00:05:43.010 --> 00:05:46.200 In fact we do 112 00:05:46.200 --> 00:05:49.380 look back at the Earth during the eclipse. 113 00:05:49.380 --> 00:05:52.430 Uh - spacecraft, one of them is called DSCOVR, 114 00:05:52.430 --> 00:05:55.490 and it sits in-between the sun and the Earth, watching 115 00:05:55.490 --> 00:05:58.570 the Earth and it will watch the eclipse as it happens. 116 00:05:58.570 --> 00:06:01.670 It will watch the shadow of the moon cast 117 00:06:01.670 --> 00:06:04.840 across the Earth and go across the Earth. 118 00:06:04.840 --> 00:06:08.030 The Lunar Reconnaissance Orbiter is another mission that usually watches 119 00:06:08.030 --> 00:06:11.230 the moon, but for this eclipse it is going to point and look 120 00:06:11.230 --> 00:06:14.290 at the Earth and watch the shadow of the moon go across the Earth. 121 00:06:14.290 --> 00:06:17.390 And the International Space Station is also going to get to see 122 00:06:17.390 --> 00:06:20.540 the shadow of the moon across the Earth. 123 00:06:20.540 --> 00:06:23.580 124 00:06:23.580 --> 00:06:26.590 Text on screen: How has our precise mapping of the moon helped us predict the path of eclipses? 125 00:06:26.590 --> 00:06:29.770 The Lunar Reconnaissance 126 00:06:29.770 --> 00:06:32.960 Orbiter has taken very precise measurements of the 127 00:06:32.960 --> 00:06:36.030 moon. It has precise measurements of the topography - 128 00:06:36.030 --> 00:06:39.140 the mountains, the valleys, the craters. Because the moon 129 00:06:39.140 --> 00:06:42.330 is not a perfect sphere, and so that shadow that it casts down 130 00:06:42.330 --> 00:06:45.510 onto the Earth is not a perfect circle. The details of 131 00:06:45.510 --> 00:06:48.700 the topography are what help us know exactly what that shadow is 132 00:06:48.700 --> 00:06:51.790 going to look like when it hits the Earth. 133 00:06:51.790 --> 00:06:54.820 Text on screen: Where can we learn more? 134 00:06:54.820 --> 00:06:58.010 135 00:06:58.010 --> 00:07:01.100 You can learn more at 136 00:07:01.100 --> 00:07:04.210 eclipse2017.nasa.gov - that's where we have 137 00:07:04.210 --> 00:07:07.360 all sorts of information. Everything from safety, 138 00:07:07.360 --> 00:07:10.550 to detailed maps of what you're going to see in 139 00:07:10.550 --> 00:07:13.720 your area. We also have 140 00:07:13.720 --> 00:07:16.760 event information, uh, local 141 00:07:16.760 --> 00:07:19.840 libraries, zoos, museums, things like that, are hosting 142 00:07:19.840 --> 00:07:22.950 eclipse parties. And you can find out what events 143 00:07:22.950 --> 00:07:26.110 are going on in your area. 144 00:07:26.110 --> 00:07:26.463