WEBVTT FILE 1 00:00:00.010 --> 00:00:08.250 [ music ] 2 00:00:08.270 --> 00:00:15.780 Mars's atmosphere is much less dense than the Earth's, it only has about one percent of the density of the Earth's atmosphere. 3 00:00:15.800 --> 00:00:20.680 However, we're pretty sure that Mars had a much thicker atmosphere in the past, 4 00:00:20.700 --> 00:00:29.550 because there's such strong evidence for running water on the surface, and to have running water, Mars's atmosphere had to be much thicker. 5 00:00:29.570 --> 00:00:39.880 Now MAVEN is going to look at how Mars lost its atmosphere, in particular whether it could have lost its atmosphere to space. 6 00:00:39.900 --> 00:00:48.260 My name is Bob Lin, I'm a professor of physics and I work at the Space Sciences Laboratory of the University of California at Berkeley. 7 00:00:48.280 --> 00:00:55.400 MAVEN is a Mars Scout mission for NASA, and it's an orbital mission to Mars 8 00:00:55.420 --> 00:00:59.660 which is designed to study the loss of the atmosphere of Mars. 9 00:00:59.680 --> 00:01:04.920 For example if there was a large solar eruption, if the solar wind increased in strength, 10 00:01:04.940 --> 00:01:10.080 we could then look at how the atmosphere gets lost in each of these situations. 11 00:01:10.100 --> 00:01:17.930 Because Mars is in the solar wind, a lot of the loss comes from these ions and electrons that are escaping, 12 00:01:17.950 --> 00:01:26.820 and the Particles and Fields package is designed to look at the escape of the charged particles from the atmosphere. 13 00:01:26.840 --> 00:01:32.730 We have the Solar Wind Ion Analyzer, which measures the incoming solar wind, 14 00:01:32.750 --> 00:01:37.630 then we have the Solar Wind Electron Analyzer, which measures the incoming solar wind electrons. 15 00:01:37.650 --> 00:01:44.730 We have the Langmuir Probe and Waves instrument, and that measures solar ultraviolet. 16 00:01:44.750 --> 00:01:50.660 It also measures low-energy electrons that might be escaping from Mars, 17 00:01:50.680 --> 00:01:56.660 and furthermore it measures waves that might be accelerating the ions so that they can escape from Mars. 18 00:01:56.680 --> 00:02:06.030 We then have the STATIC instrument. It will give us the composition of what is escaping, whether it's CO2, or hydrogen, or helium and so forth. 19 00:02:06.050 --> 00:02:11.890 The Solar Energetic Particle instrument, SEP, measures high-energy particles from the Sun, 20 00:02:11.910 --> 00:02:15.980 and those particles will hit the atmosphere and cause a lot of damage. 21 00:02:16.000 --> 00:02:24.050 And finally there's a magnetometer, which will measure the magnetic field in the solar wind and the magnetic field of Mars. 22 00:02:24.070 --> 00:02:30.140 Mars is the only planet, besides the Earth, where you really have a chance that life might have formed. 23 00:02:30.160 --> 00:02:35.390 The conditions for life are water, running water, and a reasonably thick atmosphere. 24 00:02:35.410 --> 00:02:41.570 We have a chance now to see whether that was in fact what Mars had early on, 25 00:02:41.590 --> 00:02:48.840 and whether the atmosphere was lost by this means, so we think it's an extremely important mission to do. 26 00:02:48.860 --> 00:02:53.310 [ George Diller ] Five, four, three, two, one. 27 00:02:53.330 --> 00:02:59.760 Main engine start, ignition, and liftoff of the Atlas V with MAVEN, 28 00:02:59.780 --> 00:03:07.250 looking for clues about the evolution of Mars through its atmosphere. 29 00:03:07.270 --> 00:03:13.680 [ music ] 30 00:03:13.700 --> 00:03:25.419 [ satellite beeping ]