WEBVTT FILE 1 00:00:00.601 --> 00:00:04.404 2020 will be a banner year for the exploration of Mars. 2 00:00:04.404 --> 00:00:07.908 In addition to the launch of NASA's Mars 2020 rover, the 3 00:00:07.908 --> 00:00:11.011 European Space Agency and Roscosmos are sending the 4 00:00:11.011 --> 00:00:14.014 ExoMars rover to the red planet. 5 00:00:14.014 --> 00:00:17.618 As it descends from its landing platform, ExoMars will embark on 6 00:00:17.618 --> 00:00:21.555 an enterprising mission: to uncover buried signs of past or 7 00:00:21.555 --> 00:00:22.923 present life. 8 00:00:22.923 --> 00:00:26.159 The Martian surface is a harsh environment, bombarded with 9 00:00:26.159 --> 00:00:28.695 cosmic radiation, but the subsurface 10 00:00:28.695 --> 00:00:30.364 could offer better protection. 11 00:00:30.364 --> 00:00:33.834 For this reason, ExoMars is equipped with an extending drill 12 00:00:33.834 --> 00:00:36.370 that can retrieve samples from up to two meters 13 00:00:36.370 --> 00:00:38.138 below the surface. 14 00:00:38.138 --> 00:00:41.742 Studying these samples will be the job of the Analytical Lab, a 15 00:00:41.742 --> 00:00:44.745 trio of instruments designed to search for the molecular 16 00:00:44.745 --> 00:00:46.747 fingerprints of life. 17 00:00:50.284 --> 00:00:53.987 The Mars Organic Molecule Analyzer, or MOMA, is the 18 00:00:53.987 --> 00:00:57.457 largest and most complex instrument on the rover. 19 00:00:57.457 --> 00:01:00.661 Its mass spectrometer subsystem and its main electronics were 20 00:01:00.661 --> 00:01:03.897 built and tested at NASA's Goddard Space Flight Center, 21 00:01:03.897 --> 00:01:06.600 which also contributed mass spectrometers to NASA's 22 00:01:06.600 --> 00:01:09.503 Curiosity rover and MAVEN orbiter. 23 00:01:09.503 --> 00:01:12.906 MOMA is designed with a mix of proven hardware and innovative 24 00:01:12.906 --> 00:01:15.008 new technologies. 25 00:01:15.008 --> 00:01:18.879 Here's how it works: in gas chromatograph mode, crushed 26 00:01:18.879 --> 00:01:22.316 Martian rock is put into an oven and heated to 900 degrees 27 00:01:22.316 --> 00:01:27.321 Celsius in just two minutes, vaporizing the sample. 28 00:01:27.321 --> 00:01:31.258 Molecules of hot gas rise up, and flow into a narrow, twenty 29 00:01:31.258 --> 00:01:33.226 meter-long tube. 30 00:01:33.226 --> 00:01:36.496 Special coatings inside the tube cause molecules with certain 31 00:01:36.496 --> 00:01:39.533 chemistries to slow down more than others, separating the 32 00:01:39.533 --> 00:01:41.802 mixture of molecules over time. 33 00:01:41.802 --> 00:01:45.339 Next, a beam of electrons ionizes the molecules, giving 34 00:01:45.339 --> 00:01:48.642 them a positive electric charge and deflecting them towards the 35 00:01:48.642 --> 00:01:50.377 linear ion trap. 36 00:01:50.377 --> 00:01:53.613 The ions are caught by a fluctuating electric field, and 37 00:01:53.613 --> 00:01:57.784 sent to a detector to determine their chemical makeup. 38 00:01:57.784 --> 00:02:00.787 While gas chromatography has been used to study Mars since 39 00:02:00.787 --> 00:02:04.024 the Viking program, MOMA has a second method for preparing 40 00:02:04.024 --> 00:02:07.627 samples that has never been used on another planet. 41 00:02:07.627 --> 00:02:10.764 In laser desorption mode, a sample is placed beneath a 42 00:02:10.764 --> 00:02:14.134 powerful ultraviolet laser. 43 00:02:14.134 --> 00:02:17.671 A beam of energetic light builds within the laser and fires in a 44 00:02:17.671 --> 00:02:20.474 billionth of a second, concentrating its energy onto a 45 00:02:20.474 --> 00:02:23.377 spot smaller than a grain of sand. 46 00:02:23.377 --> 00:02:26.913 This rapidly vaporizes a portion of the sample, releasing large 47 00:02:26.913 --> 00:02:30.684 organic molecules that could be broken down by oven heating. 48 00:02:30.684 --> 00:02:34.254 The laser shot also ionizes some of the molecules, allowing the 49 00:02:34.254 --> 00:02:37.758 vapor to head directly to the linear ion trap. 50 00:02:37.758 --> 00:02:41.094 Neutral molecules are ejected by a vacuum, while the remaining 51 00:02:41.094 --> 00:02:45.332 ions are sent to the detector to determine their chemical makeup. 52 00:02:45.332 --> 00:02:48.835 Laser desorption will enable MOMA to detect long molecules 53 00:02:48.835 --> 00:02:52.239 like lipids, the building blocks of cell membranes, a leap 54 00:02:52.239 --> 00:02:54.708 forward in the search for life on Mars. 55 00:02:58.912 --> 00:03:01.314 MOMA's linear ion trap is another first 56 00:03:01.314 --> 00:03:02.816 for the red planet. 57 00:03:02.816 --> 00:03:05.085 It will scan for the fingerprints of life using 58 00:03:05.085 --> 00:03:09.156 techniques normally confined to laboratories on Earth. 59 00:03:09.156 --> 00:03:12.692 One technique, called SWIFT, repeatedly ejects unwanted 60 00:03:12.692 --> 00:03:14.728 molecules from the trap. 61 00:03:14.728 --> 00:03:17.330 Over time this builds up molecules of interest, 62 00:03:17.330 --> 00:03:20.367 improving detection. 63 00:03:20.367 --> 00:03:24.638 Another technique is tandem mass spectrometry, or MS/MS, which 64 00:03:24.638 --> 00:03:27.774 identifies large molecules by breaking them apart and 65 00:03:27.774 --> 00:03:30.010 analyzing their fragments. 66 00:03:30.010 --> 00:03:34.147 By combining SWIFT and MS/MS, MOMA can determine an individual 67 00:03:34.147 --> 00:03:37.284 molecule's formula and its structure, both important 68 00:03:37.284 --> 00:03:39.586 criteria in the search for life. 69 00:03:40.921 --> 00:03:43.990 The question of life on Mars is among the most important in 70 00:03:43.990 --> 00:03:47.194 planetary science, and the evidence may be buried just 71 00:03:47.194 --> 00:03:48.562 below the surface. 72 00:03:48.562 --> 00:03:52.199 With the help of MOMA, ExoMars will take us one step closer to 73 00:03:52.199 --> 00:03:53.867 uncovering the answer. 74 00:03:53.867 --> 00:04:01.007 [music] 75 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