WEBVTT FILE 1 00:00:00.050 --> 00:00:04.059 Music 2 00:00:04.080 --> 00:00:08.070 Music 3 00:00:08.090 --> 00:00:12.080 Music 4 00:00:12.100 --> 00:00:16.079 Alex: Solar flares and coronal mass ejections do 5 00:00:16.100 --> 00:00:20.110 not always hit Earth. They happen all over the sun and depending 6 00:00:20.130 --> 00:00:24.169 on where on the sun they occur determines whether or not they're 7 00:00:24.190 --> 00:00:28.200 going to travel towards the Earth. Phil: Some of them could be shot off to the side, and just miss 8 00:00:28.220 --> 00:00:32.210 us completely. They could go up, they could go left. Some are 9 00:00:32.229 --> 00:00:36.300 like curveballs, that a pitcher will throw. They could 10 00:00:36.320 --> 00:00:40.310 seemingly come straight for us, and then miss us completely. 11 00:00:40.330 --> 00:00:44.330 Alex: Space weather can have several different effects on the 12 00:00:44.350 --> 00:00:48.360 Earth and the near-Earth environment. In space, it can create 13 00:00:48.380 --> 00:00:52.410 dangerous radiation in the form of particles, which is detrimental 14 00:00:52.430 --> 00:00:56.430 to the health of astronauts. These particles, 15 00:00:56.450 --> 00:01:00.510 as well as solar flares, can cause cause damage to 16 00:01:00.530 --> 00:01:04.590 satellites in near-Earth orbit. In addition, 17 00:01:04.610 --> 00:01:08.640 electromagnetic disturbances created by geomagnetic storms 18 00:01:08.660 --> 00:01:12.670 can affect power transmission on the ground, can also 19 00:01:12.690 --> 00:01:16.750 disrupt communication. But space weather has 20 00:01:16.770 --> 00:01:20.850 no direct effect on human beings themselves. Holly: We are protected 21 00:01:20.870 --> 00:01:24.910 here on the surface of the Earth from solar flares and coronal mass ejections 22 00:01:24.930 --> 00:01:28.930 when they impact the Earth, due to the magnetic field of the Earth called the 23 00:01:28.950 --> 00:01:32.960 magnetosphere, which deflects the magnetic field and the energetic particles 24 00:01:32.980 --> 00:01:36.990 as well as the atmosphere, which absorbs the higher levels of 25 00:01:37.010 --> 00:01:41.050 radiation. Phil: Most of the energy that's associated with a solar flare or 26 00:01:41.070 --> 00:01:45.080 coronal mass ejection doesn't even reach the surface of the Earth. So even 27 00:01:45.100 --> 00:01:49.100 the biggest of flares isn't going to affect you here at Earth. 28 00:01:49.120 --> 00:01:53.120 Music. Alex: When a large solar eruption 29 00:01:53.140 --> 00:01:57.170 occurs, there are generally three things that happen. Each of these takes 30 00:01:57.190 --> 00:02:01.200 a different amount of time to reach the Earth. The solar flare, because 31 00:02:01.220 --> 00:02:05.220 it's light, travels at the speed of light and takes approximately 8 minutes to reach 32 00:02:05.240 --> 00:02:09.259 us. The solar energetic particles are traveling extremely fast 33 00:02:09.280 --> 00:02:13.290 --close to the speed of light, but not exactly the speed of light--so they take 34 00:02:13.310 --> 00:02:17.330 roughly 20 to 30 minutes to reach us. 35 00:02:17.350 --> 00:02:21.350 The coronal mass ejection is much slower, and that takes about 36 00:02:21.370 --> 00:02:25.380 1 to 4 days to reach us. Music. 37 00:02:25.400 --> 00:02:29.460 Holly: The sun goes through what we call a solar activity cycle, 38 00:02:29.480 --> 00:02:33.570 where every 11 years on average, it will go from a very low period of 39 00:02:33.590 --> 00:02:37.610 solar activity--meaning sunspots and solar storms--to another period 40 00:02:37.630 --> 00:02:41.650 of low activity, and in-between it goes through what we call solar maximum. At solar 41 00:02:41.670 --> 00:02:45.670 maximum the sun has a very complicated magnetic field structure, and 42 00:02:45.690 --> 00:02:49.690 therefore it creates a lot more sunspots and a lot more solar storms like flares, 43 00:02:49.710 --> 00:02:53.730 and CMEs. It's very important to be able to 44 00:02:53.750 --> 00:02:57.760 forecast solar events because they can affect our technology, our 45 00:02:57.780 --> 00:03:01.800 satellites, they can cause power grids to be affected. So as we 46 00:03:01.820 --> 00:03:05.829 become more and more technologically advanced, it becomes more important to be able to forecast 47 00:03:05.850 --> 00:03:09.840 such events. Music 48 00:03:09.860 --> 00:03:13.860 Music 49 00:03:13.880 --> 00:03:17.940 Beeping 50 00:03:17.960 --> 00:03:27.350 Beeping.