WEBVTT FILE 1 00:00:00.020 --> 00:00:04.030 music 2 00:00:04.050 --> 00:00:08.080 music 3 00:00:08.100 --> 00:00:12.110 music 4 00:00:12.130 --> 00:00:16.140 Tom Moore: Magnetic reconnection is the process of disconnecting or connecting 5 00:00:16.160 --> 00:00:20.190 the magnetic fields to each other, directing energy into the Earth on the dayside 6 00:00:20.210 --> 00:00:24.210 and then letting it go on the nightside. The interplay between the 7 00:00:24.230 --> 00:00:28.260 2 is what produces all the space weather around the Earth that 8 00:00:28.280 --> 00:00:32.280 has big effects, can damage our spacecraft, can 9 00:00:32.300 --> 00:00:36.290 hurt astronauts, can upset the flow of electrical energy in our electric grid 10 00:00:36.310 --> 00:00:40.350 on the surface of the Earth. MMS is a mission with 4 spacecraft 11 00:00:40.370 --> 00:00:44.380 that travel in formation, in an orbit that takes them 12 00:00:44.400 --> 00:00:48.450 out into 2 special places near the Earth, 13 00:00:48.470 --> 00:00:52.470 one upstream toward the sun, one downstream away from the sun. 14 00:00:52.490 --> 00:00:56.490 Both of those place have magnetic reconnection. 15 00:00:56.510 --> 00:01:00.510 We have never before MMS had the ability to 16 00:01:00.530 --> 00:01:04.570 essentially run the camera fast enough to catch it 17 00:01:04.590 --> 00:01:08.600 as it goes by, to make many measurements per second. 18 00:01:08.620 --> 00:01:12.650 The science payload for MMS is all mounted on a single deck plate. 19 00:01:12.670 --> 00:01:16.670 It consists of some 25 boxes per spacecraft, 20 00:01:16.690 --> 00:01:20.700 divided into 3 general groups of instruments. That's those measuring 21 00:01:20.720 --> 00:01:24.710 fields (electric and magnetic), those for measuring plasmas, 22 00:01:24.730 --> 00:01:28.720 and a third for measuring energetic particles. 23 00:01:28.740 --> 00:01:32.760 The magnetic field sensors are out on arms that extend away from the spacecraft. They are fixed, but the spacecraft is 24 00:01:32.780 --> 00:01:36.780 spinning slowly, about once every 20 seconds. 25 00:01:36.800 --> 00:01:40.830 The electric field is quite a bit different. It consists of 4 wires 26 00:01:40.850 --> 00:01:44.890 that extend out away from the spacecraft with a ball out on the end of each of them. 27 00:01:44.910 --> 00:01:48.940 that actually contacts the plasma. 28 00:01:48.960 --> 00:01:52.980 All 4 of those are spinning around with the spacecraft with this 20 second period. 29 00:01:53.000 --> 00:01:57.010 And then there's a third axis, there's booms that extend along 30 00:01:57.030 --> 00:02:01.070 the spin axis of the spacecraft, both upward and downward with the probe at the end. 31 00:02:01.090 --> 00:02:05.090 So you've got 3 components of the electric field. They can measure everything from 32 00:02:05.110 --> 00:02:09.140 up to small wiggles and vibrations of the electric field. 33 00:02:09.160 --> 00:02:13.180 Another sensor is called the search coil magnetometer is just a loop of wire 34 00:02:13.200 --> 00:02:17.210 connected to a suitable amplifier, and it is designed 35 00:02:17.230 --> 00:02:21.240 to measure the fluctuations at higher frequencies than you could get 36 00:02:21.260 --> 00:02:25.290 with the DC magnetometers. For the plasmas 37 00:02:25.310 --> 00:02:29.320 8 boxes. 2 boxes at each of the 4 points of the compass on the spacecraft. 38 00:02:29.340 --> 00:02:33.350 Those are equally spaced all around the spacecraft. That is a real 39 00:02:33.370 --> 00:02:37.400 key ingredient for being able to see the 40 00:02:37.420 --> 00:02:41.440 entire sky instantaneously, without waiting for the spacecraft to spin 41 00:02:41.460 --> 00:02:45.460 Then there is also the hot plasma composition analyzer 42 00:02:45.480 --> 00:02:49.500 1 per spacecraft. It has sensor head that looks all around in a 43 00:02:49.520 --> 00:02:53.530 360 degree annulus that sticks out the side of the spacecraft 44 00:02:53.550 --> 00:02:57.560 and sweeps out the whole sky twice per spin. 45 00:02:57.580 --> 00:03:01.570 It measures the chemical species of the particles. 46 00:03:01.590 --> 00:03:05.590 Next are the accelerated particle analyzers that are measuring much more energetic particles 47 00:03:05.610 --> 00:03:09.630 that are accelerated by the reconnection process. 48 00:03:09.650 --> 00:03:13.660 Ultimately, what we will be doing is comparing our observations with simulations of the entire magnetoshere 49 00:03:13.680 --> 00:03:17.730 as it is influenced with the solar wind coming in, down to the 50 00:03:17.750 --> 00:03:21.770 details of what reconnection is occurring. People who do 51 00:03:21.790 --> 00:03:25.800 those simulations try to apply them to all other kinds of places, like in the solar 52 00:03:25.820 --> 00:03:29.850 atmosphere and other astrophysical stars 53 00:03:29.870 --> 00:03:33.900 and other objects. They are very interested in 54 00:03:33.920 --> 00:03:37.990 whether those simulations are accurate and reflect reality well 55 00:03:38.010 --> 00:03:42.000 This is going to be the first time we actually bump them up against hard data of what's going 56 00:03:42.020 --> 00:03:46.050 in there. I am almost certain, I'm very certain, they are gonna learn something 57 00:03:46.070 --> 00:03:50.100 from that and the simulations will get better. 58 00:03:50.120 --> 00:03:54.120 We are going to measure things at rates that have never been done before, in places that 59 00:03:54.140 --> 00:03:58.130 have been hard to reach and even see, because they go by to fast 60 00:03:58.150 --> 00:04:02.160 so, it's going to be fantastic. 61 00:04:02.180 --> 00:04:04.391 beeping