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.