WEBVTT FILE 1 00:00:00.040 --> 00:00:04.070 Voice Off Screen: So the evolution of Mars from a warm and wet planet to the cold and dry desert 2 00:00:04.070 --> 00:00:08.120 we see today is one of our solar system's biggest secrets 3 00:00:08.120 --> 00:00:12.190 and shedding a little bit of light on that secret is NASA's MAVEN mission. 4 00:00:12.190 --> 00:00:16.260 Here to tell us more about it from NASA's Goddard Space Flight Center in 5 00:00:16.260 --> 00:00:20.350 Greenbelt, Maryland is NASA Scientist Dr. Jared Espley. Thank you 6 00:00:20.350 --> 00:00:21.390 for joining us. 7 00:00:21.390 --> 00:00:22.600 Thank You. 8 00:00:22.600 --> 00:00:26.140 Voice Off Screen: So MAVEN is returning some exciting results on the martian atmosphere 9 00:00:26.140 --> 00:00:28.120 what are we seeing? 10 00:00:28.120 --> 00:00:32.500 So MAVEN is NASA's most recent Mars mission, its actually in orbit around the planet 11 00:00:32.500 --> 00:00:36.520 right now. It's main purpose is to investigate what caused 12 00:00:36.520 --> 00:00:40.530 most of the martian atmosphere to disappear over time. 13 00:00:40.530 --> 00:00:44.590 What I really mean by that is that we know that ancient Mars was a warm, wet 14 00:00:44.590 --> 00:00:48.610 and possibly habitable environment. Whereas modern Mars is 15 00:00:48.610 --> 00:00:52.670 clearly a cold, dry, and desolate place. So the question we'd like to answer is 16 00:00:52.670 --> 00:00:56.770 "how did that come to be?" and with MAVEN we have the instruments to actually directly observe 17 00:00:56.770 --> 00:01:00.890 this. We're seeing that the solar wind, this thin stream of gas flowing out 18 00:01:00.890 --> 00:01:05.010 from the sun, is actually washing over the martian atmosphere and blowing it away 19 00:01:05.010 --> 00:01:09.040 bit by bit so that over billions of years its been lost in an interplanetary 20 00:01:09.040 --> 00:01:11.650 space forever. 21 00:01:11.650 --> 00:01:13.080 Voice Off Screen: Fascinating 22 00:01:13.080 --> 00:01:17.150 So what role does atmosphereic loss play in Mars' ability to 23 00:01:17.150 --> 00:01:18.900 support life? 24 00:01:18.900 --> 00:01:23.600 So everywhere that we find with life on Earth its associated with water. 25 00:01:23.600 --> 00:01:25.330 So the question really comes down to 26 00:01:25.330 --> 00:01:29.460 "Where can we find the water at Mars?" and so as 27 00:01:29.460 --> 00:01:33.490 we talked about we actually think that Mars used to have a lot of liquid water on it 28 00:01:33.490 --> 00:01:37.520 surface, but we see only today dry riverbeds, dry lakes, 29 00:01:37.520 --> 00:01:41.550 dry gullies so something had to have happened to cause the atmosphere 30 00:01:41.550 --> 00:01:45.590 and the water to go away, so that water could have either flown off 31 00:01:45.590 --> 00:01:49.660 into space, been driven away into space, or gone into the subsurface. 32 00:01:49.660 --> 00:01:53.690 And with MAVEN we're starting to see it clearly was driven off into space at least 33 00:01:53.690 --> 00:01:57.780 a part. And so we're able to start addressing that question of where the water went. 34 00:01:57.780 --> 00:02:01.900 Where the atmosphere went, and therefore the potential for life at Mars. 35 00:02:01.900 --> 00:02:06.070 Voice Off Screen: Now what is MAVEN telling us about the impact of the Sun 36 00:02:06.070 --> 00:02:08.140 on the martian climate? 37 00:02:08.140 --> 00:02:10.100 So like we just talked about the main culprit 38 00:02:10.100 --> 00:02:14.150 we think at the moment is the solar wind to drive away the martian atmosphere 39 00:02:14.150 --> 00:02:18.210 but one of the really interesting things of course is the Sun itself has these beautiful 40 00:02:18.210 --> 00:02:22.290 solar storms, these filamentary archs 41 00:02:22.290 --> 00:02:26.360 of high energy gas that come flowing off of the Sun that makes these solar 42 00:02:26.360 --> 00:02:30.470 storms. And as these storms wash over the planet we wonder if they would be 43 00:02:30.470 --> 00:02:34.610 they would be able to create even greater atmospheric loss than just a steady state solar 44 00:02:34.610 --> 00:02:38.630 wind. So we're interested in studying the steady state solar wind and comparing it 45 00:02:38.630 --> 00:02:42.680 to what the atmosphere does when the huge solar storms wash over the planet. 46 00:02:42.680 --> 00:02:46.780 Voice Off Screen: Interesting. So now a recent NASA discovery has found 47 00:02:46.780 --> 00:02:50.850 water on Mars' surface. So how do MAVEN's results help us 48 00:02:50.850 --> 00:02:54.970 understand what has actually happened to water on the planet? 49 00:02:54.970 --> 00:02:59.100 Right, so that was a really interesting result because it showed that there was thin films 50 00:02:59.100 --> 00:03:03.130 of water that occur seasonally on Mars today. So liquid water today 51 00:03:03.130 --> 00:03:07.160 on the surface of the planet. And then MAVEN is interested in the big picture question 52 00:03:07.160 --> 00:03:11.180 of how water has evolved over time at Mars at a planet 53 00:03:11.180 --> 00:03:15.200 ary scale. What happened to the water that carved the dry river beds that we see? 54 00:03:15.200 --> 00:03:19.260 And so together with the results of tiny bits of liquid water available today 55 00:03:19.260 --> 00:03:23.350 and it's history of water that we're getting from MAVEN and how it's been lost to space 56 00:03:23.350 --> 00:03:27.450 mostly, which is starting to answer the big picture question of the evolution of 57 00:03:27.450 --> 00:03:29.970 water at Mars. 58 00:03:29.970 --> 00:03:31.580 Voice Off Screen: Where can we go to learn more 59 00:03:31.580 --> 00:03:34.000 about MAVEN and NASA's future with Mars? 60 00:03:34.000 --> 00:03:35.600 You can learn more at 61 00:03:35.600 --> 00:03:39.680 nasa.gov/maven, there's all kinds of really cool science visualizations 62 00:03:39.680 --> 00:03:43.730 and interesting videos about our mission and the results that we're getting. 63 00:03:43.730 --> 00:03:47.790 Voice Off Screen: Dr. Jared Espley thank you so much for joining us. 64 00:03:47.790 --> 00:03:49.029 Thank you.