WEBVTT FILE 1 00:00:00.000 --> 00:00:02.160 tone 2 00:00:02.180 --> 00:00:04.160 3 00:00:04.180 --> 00:00:06.160 music 4 00:00:06.180 --> 00:00:09.380 Michael Hesse: The MMS Mission is a mission 5 00:00:09.400 --> 00:00:12.380 consisting of 4 spacecraft which will fly in close constellation 6 00:00:12.400 --> 00:00:15.450 to measure a process called magnetic reconnection. 7 00:00:15.470 --> 00:00:18.620 John Dorelli: The universe is full of plasma and it's full of magnetic fields, 8 00:00:18.640 --> 00:00:21.790 and all over the place in the universe, 9 00:00:21.810 --> 00:00:24.800 you have one plasma colliding with another. An example of that is 10 00:00:24.820 --> 00:00:27.980 the solar wind coming in and colliding with Earth's magnetosphere. 11 00:00:28.000 --> 00:00:31.440 The magnetic energy in the plasma, some fraction of that 12 00:00:31.460 --> 00:00:34.560 of the magnetic energy is converted very rapidly into plasma energy. 13 00:00:34.580 --> 00:00:37.600 You can think of it as kind of like a magnetic explosion. 14 00:00:37.620 --> 00:00:40.600 The reason this is important is 15 00:00:40.620 --> 00:00:43.740 these explosions drive a lot of the weather 16 00:00:43.760 --> 00:00:46.750 patterns that we see in the magnetosphere, so what space scientists 17 00:00:46.770 --> 00:00:49.920 like to refer to as space weather. 18 00:00:49.940 --> 00:00:52.930 These space weather phenomena can have impact 19 00:00:52.950 --> 00:00:56.090 on our every day lives. It can actually affect communications 20 00:00:56.110 --> 00:00:59.170 satellites, the power grid. So, we would really like to understand 21 00:00:59.190 --> 00:01:02.180 how these magnetic explosions work. 22 00:01:02.200 --> 00:01:05.260 Michael Hesse: We need to measure magnetic reconnection in more than one location. 23 00:01:05.280 --> 00:01:08.340 Basically, how it varies in space, how it varies 24 00:01:08.360 --> 00:01:11.530 all 3 spacial dimensions. That requires a 25 00:01:11.550 --> 00:01:14.700 a tetrahedron. The additional, fantastic benefit 26 00:01:14.720 --> 00:01:17.760 that that provides is that it will actually enable 27 00:01:17.780 --> 00:01:21.050 us to recognize that we are looking at a reconnection region 28 00:01:21.070 --> 00:01:24.060 much easier than a single spacecraft. John Dorelli: The idea situation 29 00:01:24.080 --> 00:01:27.220 we would like the 4 spacecraft to kind of be surrounding 30 00:01:27.240 --> 00:01:30.610 this region where the explosion is happening. 31 00:01:30.630 --> 00:01:33.780 The separation of the spacecraft is about 10 - 100 kilometers, which makes 32 00:01:33.800 --> 00:01:36.850 it may seem like a long distance, but in terms of the magnetosphere, 33 00:01:36.870 --> 00:01:39.850 which is absolutely huge, this is really a microscopic 34 00:01:39.870 --> 00:01:42.850 region we are trying to cover. Micheal Hesse: MSS has, in a nutshell, 35 00:01:42.870 --> 00:01:46.220 2 orbital phases which are designed to study 36 00:01:46.240 --> 00:01:49.220 reconnection. 37 00:01:49.240 --> 00:01:52.470 John Dorelli: On the day side, you have situation where the solar wind is just constantly running 38 00:01:52.490 --> 00:01:55.730 into Earth's magnetic field. This is really great for MMS, 39 00:01:55.750 --> 00:01:58.880 because we know at some point MMS is going 40 00:01:58.900 --> 00:02:02.030 encounter this region. Our hope is that 41 00:02:02.050 --> 00:02:05.220 since this process is always happening we are gonna get lucky 42 00:02:05.240 --> 00:02:08.300 and actually fly right through the magnetic 43 00:02:08.320 --> 00:02:11.300 explosion as it is happening. Now, on the nightside, 44 00:02:11.320 --> 00:02:14.300 the situation is a little bit different. What happens you have a more 45 00:02:14.320 --> 00:02:17.520 gradual build up of magnetic energy in the tale, 46 00:02:17.540 --> 00:02:20.700 and these reconnection processes, these magnetic explosions, 47 00:02:20.720 --> 00:02:23.710 can just sort of pop off randomly 48 00:02:23.730 --> 00:02:26.840 we don't really know when it's gonna happen or when it's gonna happen in the tail. 49 00:02:26.860 --> 00:02:30.010 Michael Hesse: We need to understand both of those, if we want to understand how the magnetophere works 50 00:02:30.030 --> 00:02:33.210 And we believe that both of those scenarios are also very important for us 51 00:02:33.230 --> 00:02:36.220 for other applications, such as on the sun, 52 00:02:36.240 --> 00:02:39.400 in the solar wind, in planetary magnetospheres, 53 00:02:39.420 --> 00:02:42.400 and many astrophysical objects 54 00:02:42.420 --> 00:02:45.470 as well as in the laboratory. John Dorelli: We hope that is going to allow us to improve 55 00:02:45.490 --> 00:02:48.470 our models so that we can put the right physics in it 56 00:02:48.490 --> 00:02:51.620 and actually make predictions about where and when reconnection 57 00:02:51.640 --> 00:02:54.800 is going to happen, and this will help us make our space weather models more predicatively powerful 58 00:02:54.820 --> 00:02:57.860 The instruments that are actually going to be measuring 59 00:02:57.880 --> 00:03:01.040 the particles in space are collecting them much more rapidly 60 00:03:01.060 --> 00:03:04.060 at a much higher cadence than they have 61 00:03:04.080 --> 00:03:07.060 on previous missions, by about a factor of 100. 62 00:03:07.080 --> 00:03:10.100 Whereas it would, you know a previous generation particle instrument 63 00:03:10.120 --> 00:03:13.170 about 3 or 4 seconds 64 00:03:13.190 --> 00:03:16.230 to build up a whole picture of the sky, it's going to take 65 00:03:16.250 --> 00:03:19.240 MMS about 30 milliseconds. 66 00:03:19.260 --> 00:03:22.240 So, it really is sort of game changing technology. 67 00:03:22.260 --> 00:03:25.450 music 68 00:03:25.470 --> 00:03:28.540 beeping 69 00:03:28.560 --> 00:03:34.928 beeping