WEBVTT FILE 1 00:00:00.010 --> 00:00:04.020 Inteviewer: So the evolution of Mars from a warm and wet planet to the cold 2 00:00:04.020 --> 00:00:08.220 and dry desert we see today is one of our solar system's 3 00:00:08.220 --> 00:00:09.410 biggest secrets. 4 00:00:09.410 --> 00:00:13.600 Thanks to NASA's MAVEN mission studying the martian atmosphere 5 00:00:13.600 --> 00:00:16.810 we are now shedding a little bit of light on that secret. 6 00:00:16.810 --> 00:00:20.820 And here to tell us more about it from NASA's Goddard Space Flight Center 7 00:00:20.820 --> 00:00:24.840 in Greenbelt, Maryland is MAVEN's Principal Investigator Dr. Bruce Jakosky. 8 00:00:24.840 --> 00:00:25.850 Interviewer: Thank you for joining us. 9 00:00:25.850 --> 00:00:26.870 Bruce: Thank you 10 00:00:26.870 --> 00:00:31.090 Interviewer: So MAVEN is returning some exciting results on the martian atmosphere 11 00:00:31.090 --> 00:00:32.290 What are we seeing? 12 00:00:32.290 --> 00:00:36.300 Bruce: The MAVEN mission is all about learning the history 13 00:00:36.300 --> 00:00:40.480 of the Mars invironment. We have a lot of evidence from previous 14 00:00:40.480 --> 00:00:44.480 missions that ancient Mars was warmer 15 00:00:44.480 --> 00:00:47.650 wetter place then the cold dry desert planet we see today. 16 00:00:47.650 --> 00:00:50.880 And we want to understand the driver behind that. 17 00:00:50.880 --> 00:00:54.910 To what extent has the atmosphere been lost out the top 18 00:00:54.910 --> 00:00:57.110 to space, stripped away by the solar wind? 19 00:00:57.110 --> 00:01:01.310 Interviewer: Now what role does atmospheric lose actually play 20 00:01:01.310 --> 00:01:03.590 in Mar's ability to support life? 21 00:01:03.590 --> 00:01:08.610 Bruce: With the solar wind being able to strip away the atmosphere. 22 00:01:08.610 --> 00:01:11.790 We have the ability to go from a planet capable of 23 00:01:11.790 --> 00:01:15.000 supporting life with liquid water at the surface 24 00:01:15.000 --> 00:01:19.030 early in it's history as the atmosphere disappeared 25 00:01:19.030 --> 00:01:20.230 and the planet got colder. 26 00:01:20.230 --> 00:01:23.250 LIquid water would have become more scarce 27 00:01:23.250 --> 00:01:26.290 more rare and eventually disappeared essentially entirely. 28 00:01:26.290 --> 00:01:29.320 Mar's would have gone from a planet capable of supporting 29 00:01:29.320 --> 00:01:33.520 life at the surface to one that really isn't able to support life today. 30 00:01:33.520 --> 00:01:35.700 Interviewer: Wow fascinating. 31 00:01:35.700 --> 00:01:39.770 So what is MAVEN telling us about the impact of the sun on the martian climate? 32 00:01:39.770 --> 00:01:43.790 Bruce: We hadn't really expected that the sun would be able to affect the 33 00:01:43.790 --> 00:01:46.980 geology, the atmosphere, and climate. 34 00:01:46.980 --> 00:01:51.170 So we are seeing the lose of the atmosphere is driven by the sun 35 00:01:51.170 --> 00:01:56.180 by the solar wind, by solar ultraviolet radiation, by solar storm events. 36 00:01:56.180 --> 00:02:01.720 And over time these are capable of stripping away a large amount of atmospheric gas 37 00:02:01.720 --> 00:02:03.730 and changing the climate. 38 00:02:03.730 --> 00:02:08.910 Interviewer: So a NASA discovery recently has found water on Mar's surface. 39 00:02:08.910 --> 00:02:14.090 How do MAVEN's results help us understand what is actually happened to water on the planet? 40 00:02:14.090 --> 00:02:18.090 Bruce: The processes that we're exploring really operate over billions of years 41 00:02:18.090 --> 00:02:22.290 so we are looking at the long term evolution of the climate, evolution of the atmosphere. 42 00:02:22.290 --> 00:02:26.300 Some of the recent results about liquid water on the surface tell us 43 00:02:26.300 --> 00:02:29.340 about trace amounts of liquid that might me present today 44 00:02:29.340 --> 00:02:32.560 as a transient rather then something that is stable. 45 00:02:32.560 --> 00:02:36.570 Together their telling us about the overall history 46 00:02:36.570 --> 00:02:40.610 of liquid water, the history of the atmosphere as a whole. 47 00:02:40.610 --> 00:02:44.630 Interviewer: Where can we go to learn more about MAVEN 48 00:02:44.630 --> 00:02:46.810 and NASA's future with Mars? 49 00:02:46.810 --> 00:02:50.010 Bruce: You can go to nasa.gov/maven 50 00:02:50.010 --> 00:02:52.040 and there you will find some of the recent results 51 00:02:52.040 --> 00:02:55.050 along with some really cool videos showing how they operate. 52 00:02:55.050 --> 00:02:55.459