WEBVTT FILE 1 00:00:00.020 --> 00:00:04.070 NASA is celebrating a big anniversary, it's the 10th 2 00:00:04.070 --> 00:00:08.100 anniversary of the STEREO satellites that are orbiting 3 00:00:08.100 --> 00:00:12.150 the Sun and returning some interesting data and here to tell us about what NASA 4 00:00:12.150 --> 00:00:16.150 is learning about the Sun is Dr. Eric Christian at NASA's Goddard Space Flight Center 5 00:00:16.150 --> 00:00:20.310 thanks for joining us. [Eric] Thank you. [Voice off Screen] Now, start by telling us 6 00:00:20.310 --> 00:00:24.500 What is space weather and why does it matter to us on earth? 7 00:00:24.500 --> 00:00:28.510 So the Sun actually has storms, so 8 00:00:28.510 --> 00:00:32.670 the storms from the Sun can affect us here on Earth. 9 00:00:32.670 --> 00:00:36.760 Luckily we're mostly protected by the Earth's magnetic field and the 10 00:00:36.760 --> 00:00:40.950 Earth's atmosphere, but even so, se can see 11 00:00:40.950 --> 00:00:44.960 the wonderful aurora that's caused by space weather but it can also 12 00:00:44.960 --> 00:00:48.980 cause problems with the power grid. Power outages actually have been caused by solar storm 13 00:00:48.980 --> 00:00:53.170 it can affect communications, and as we get more technology and as we 14 00:00:53.170 --> 00:00:57.250 explore the solar system, it can affect satellites 15 00:00:57.250 --> 00:01:01.350 it can certainly affect astronauts especially as they get further away from the Earth, let's say on their way to Mars 16 00:01:01.350 --> 00:01:05.540 [Voice off Screen] Now how has STEREO changed our understanding 17 00:01:05.540 --> 00:01:09.550 of the Sun? [Eric] So STEREO has done two things for the first time 18 00:01:09.550 --> 00:01:13.560 One is, that the two STEREO spacecraft had identical cameras 19 00:01:13.560 --> 00:01:17.570 and just as you need two eyes to see three dimensions 20 00:01:17.570 --> 00:01:21.610 STEREO gave us 3d images of these solar storms, there coronal mass 21 00:01:21.610 --> 00:01:25.620 ejections, these solar flares, these prominences so that we could really understand 22 00:01:25.620 --> 00:01:29.630 the structure of them in three dimensions. The other thing is that 23 00:01:29.630 --> 00:01:33.650 these two STEREO spacecraft drifted away from the Earth and right now they are on the backside 24 00:01:33.650 --> 00:01:37.660 of the Sun, and so with STEREO.. Before STEREO we were only able to see the side 25 00:01:37.660 --> 00:01:41.670 of the Sun that was facing the Earth, now for the first time we can see 26 00:01:41.670 --> 00:01:45.680 the entire Sun 360 degrees at one time. 27 00:01:45.680 --> 00:01:49.700 And really understand how the entire Sun is changing. 28 00:01:49.700 --> 00:01:53.720 [Voice off Screen] Now we're gearing up for the solar event of the century in the US, the August 29 00:01:53.720 --> 00:01:57.900 2017 solar eclipse. how does and eclipse like this help us understand 30 00:01:57.900 --> 00:02:01.910 the Sun? [Eric] So one, an eclipse is an amazing 31 00:02:01.910 --> 00:02:06.030 to see, I've seen two in my life, they are absolutely awe inspiring, but 32 00:02:06.030 --> 00:02:10.110 we can actually do science from the eclipse and there's two 33 00:02:10.110 --> 00:02:14.210 useful things we can do. One is, that even though we have fake 34 00:02:14.210 --> 00:02:18.400 solar eclipses, we have telescopes that are called coronagraphs that block the light 35 00:02:18.400 --> 00:02:22.590 behind the sun and look the much dimmer solar atmosphere, the solar corona. 36 00:02:22.590 --> 00:02:26.610 They can't get all the way to the surface of the Sun where all 37 00:02:26.610 --> 00:02:30.610 action is happening. The Moon happens to be almost a perfect fit in size 38 00:02:30.610 --> 00:02:34.680 for the Sun, so we can see the solar corona all the way down to the 39 00:02:34.680 --> 00:02:38.680 surface of the Sun. The other thing is that 40 00:02:38.680 --> 00:02:42.680 solar eclipses, we can test instruments that are looking at the solar corona 41 00:02:42.680 --> 00:02:46.690 here on the ground, which is a lot cheaper than flying them into space. 42 00:02:46.690 --> 00:02:50.690 [Voice off Screen] NASA has an upcoming mission that will for the first time 43 00:02:50.690 --> 00:02:54.690 actually touch the Sun which sounds pretty amazing, tell us about 44 00:02:54.690 --> 00:02:58.700 this mission. [Eric] So in two years we're going to launch Solar Probe Plus, 45 00:02:58.700 --> 00:03:02.900 and Solar Pro Plus is going to travel 25 times closer to the Sun 46 00:03:02.900 --> 00:03:06.960 than the Earth is, within four million miles of the surface of the Sun 47 00:03:06.960 --> 00:03:10.970 and we can learn a lot of the Sun from looking at it from Earth 48 00:03:10.970 --> 00:03:14.980 but, getting right in to where the 49 00:03:14.980 --> 00:03:19.010 solar corona is heating up and where the solar wind is accelerated, we're going to learn so much 50 00:03:19.010 --> 00:03:23.130 more, it's going to be a fantastic mission. [Voice off Screen] Now we heard that 51 00:03:23.130 --> 00:03:27.150 STEREO-B was giving NASA the silent treatment for a while, tell us 52 00:03:27.150 --> 00:03:31.160 what happened. So after eight years of working great 53 00:03:31.160 --> 00:03:35.200 as we were getting ready for the two STEREO spacecraft to cross behind the Sun 54 00:03:35.200 --> 00:03:39.380 during which we knew we were going to lose communications with them because you can't send a radio 55 00:03:39.380 --> 00:03:43.390 signal right through the Sun, during the testing for that period 56 00:03:43.390 --> 00:03:47.400 STEREO-B had an anomaly and it started to drift so that 57 00:03:47.400 --> 00:03:51.570 the solar arrays were no longer pointed at the Sun and the antenna was no longer pointed at the 58 00:03:51.570 --> 00:03:55.750 Earth, and we lost contact with it. A couple months ago 59 00:03:55.750 --> 00:03:59.760 we actually heard from it again, and were able to get some data and some commands back in 60 00:03:59.760 --> 00:04:03.760 forth, and then lost it once more but we've got real hope 61 00:04:03.760 --> 00:04:07.940 that as it gets closer to the Earth, we'll be able to pick it up again and completely recover 62 00:04:07.940 --> 00:04:11.970 STEREO-B, STEREO-A is working great. 63 00:04:11.970 --> 00:04:16.150 [Voice off Screen] Where can we learn more and see some of these images? 64 00:04:16.150 --> 00:04:20.250 So NASA has a really wide presence on the internet in social media 65 00:04:20.250 --> 00:04:24.260 and you can go to the nasa.gov website and theres 66 00:04:24.260 --> 00:04:28.270 a backslash stereo part of that, that gives you the images that 67 00:04:28.270 --> 00:04:32.470 directly come from the STEREO mission, and we've got a Twitter feed 68 00:04:32.470 --> 00:04:36.650 @NASASunEarth where you can find out a lot of what's happening with space weather. 69 00:04:36.650 --> 00:04:41.047 [Voice off Screen] Great, thanks so much for joining us. [Eric] Thank you.