1 00:00:00,050 --> 00:00:03,237 Have you ever tried to listen to your favorite radio station only 2 00:00:03,237 --> 00:00:05,772 to find it garbled or replaced by a different station? 3 00:00:05,772 --> 00:00:08,892 Well if so, you might’ve been the victim of something known as 4 00:00:08,892 --> 00:00:13,130 a “Sporadic-E Layer.” They’re concentrations of electrically 5 00:00:13,130 --> 00:00:16,166 charged gas called plasma in a region of space known as the 6 00:00:16,166 --> 00:00:16,984 ionosphere. 7 00:00:16,984 --> 00:00:20,270 They act kind of like mirrors in the sky, and bounce radio 8 00:00:20,270 --> 00:00:23,373 transmissions over the horizon and interfere with your radio, 9 00:00:23,373 --> 00:00:26,610 kind of like two people trying to talk over each other. 10 00:00:26,610 --> 00:00:29,429 Even though we’ve known about these layers for over 80 years 11 00:00:29,429 --> 00:00:32,633 now, we still don’t fully understand them because they 12 00:00:32,633 --> 00:00:35,202 occur at an altitude that is really difficult to explore. 13 00:00:35,202 --> 00:00:38,689 The air there is so thin that we can’t fly an aircraft, but it’s 14 00:00:38,689 --> 00:00:41,425 just thick enough that if we were to try to orbit a satellite 15 00:00:41,425 --> 00:00:42,759 it would burn up in the atmosphere. 16 00:00:42,759 --> 00:00:45,295 So we’ve only ever been able to explore a handful. 17 00:00:45,295 --> 00:00:48,365 Well, one planet where the atmosphere is much thinner is 18 00:00:48,365 --> 00:00:49,700 the planet Mars. 19 00:00:49,700 --> 00:00:52,469 And one satellite that is currently exploring Mars is the 20 00:00:52,469 --> 00:00:54,037 MAVEN orbiter. 21 00:00:54,037 --> 00:00:56,406 One of the instruments on MAVEN is called STATIC. 22 00:00:56,406 --> 00:00:58,959 It’s designed to measure plasma escaping from the ionosphere, 23 00:00:58,959 --> 00:01:01,995 this upper atmospheric layer of Mars. 24 00:01:01,995 --> 00:01:04,815 And in the data, scientists were seeing that when MAVEN would fly 25 00:01:04,815 --> 00:01:07,150 through a certain region of the atmosphere, POOF! 26 00:01:07,150 --> 00:01:09,686 There was this big density enhancement of this plasma 27 00:01:09,686 --> 00:01:10,971 concentration. 28 00:01:10,971 --> 00:01:13,657 Scientists realized that they had discovered the Martian 29 00:01:13,657 --> 00:01:14,875 equivalent of these layers! 30 00:01:14,875 --> 00:01:17,644 It’s exciting because now we have a place that we can go to 31 00:01:17,644 --> 00:01:20,297 directly explore these layers with a satellite. 32 00:01:20,297 --> 00:01:23,166 MAVEN has encountered more of these layers at Mars than we’ve 33 00:01:23,166 --> 00:01:24,551 ever been able to explore here at Earth. 34 00:01:24,551 --> 00:01:27,688 At Earth, the layers are temporary and unpredictable, but 35 00:01:27,688 --> 00:01:30,374 at Mars they seem to be almost permanent and long-lived at 36 00:01:30,374 --> 00:01:31,908 predictable locations. 37 00:01:31,908 --> 00:01:34,461 Also, scientists found something that they didn’t even know could 38 00:01:34,461 --> 00:01:35,145 exist. 39 00:01:35,145 --> 00:01:37,197 MAVEN discovered the opposite of a layer. 40 00:01:37,197 --> 00:01:39,750 They’re calling it a “rift” and it’s where the sky has been 41 00:01:39,750 --> 00:01:40,550 pulled apart. 42 00:01:40,550 --> 00:01:43,420 And rather than a concentration of this plasma, there’s a 43 00:01:43,420 --> 00:01:44,087 depletion. 44 00:01:44,087 --> 00:01:47,107 Many models said this actually couldn’t happen, but yet they do 45 00:01:47,107 --> 00:01:49,676 exist and we find them at Mars. 46 00:01:49,676 --> 00:01:52,746 This demonstrates how little we actually know, and how much 47 00:01:52,746 --> 00:01:54,398 there still is to discover. 48 00:01:54,398 --> 00:01:57,217 These layers are so common – they happen over our heads all 49 00:01:57,217 --> 00:01:57,884 the time. 50 00:01:57,884 --> 00:02:00,003 You yourself have probably detected one of these with your 51 00:02:00,003 --> 00:02:02,372 own radio, even if you weren’t aware of it. 52 00:02:02,372 --> 00:02:04,691 And who would’ve thought that one of the best ways to explore 53 00:02:04,691 --> 00:02:07,661 them would be to send a spacecraft 300 million miles to 54 00:02:07,661 --> 00:02:10,347 the red planet. 55 00:02:10,347 --> 00:00:00,000 [music]