The 2004 Mars Exploration Rover Mission: Evidence for Water and Prospects for Life

Transcription

1 # 38 The 2004 Mars Exploration Rover Mission: Evidence for Water and Prospects for Life Dr. John Grotzinger October 13, 2005 Produced by and for Hot Science - Cool Talks by the Environmental Science Institute. We request that the use of these materials include an acknowledgement of the presenter and Hot Science - Cool Talks by the Environmental Science Institute at UT Austin. We hope you find these materials educational and enjoyable.

2 The 2004 Mars Exploration Rover Mission: Evidence for Water and Prospects for Life John Grotzinger on behalf of MER Athena Science Team

3 Common Thread Mars Science Strategy: Follow the Water! LIFE CLIMATE Mars Science Strategy GEOLOGY HUMAN

4 The Athena Science Payload Remote Sensing Package Pancam Mast Assembly (PMA) Pancam Mini-TES The Athena Science Payload In-Situ Package Instrument Deployment Device (IDD) Microscopic Imager Alpha Particle X-Ray Spectrometer Mössbauer Spectrometer Rock Abrasion Tool Magnetic Properties Experiment

5 The Team The Team

6 Mars Pathfinder Mars Pathfinder

7 The MER Rover

8 Wrap it up and cram it in Wrap it up and cram it in

9 The Three Challenging Mission Phases Launch & Cruise Entry, Descent & Landing The Three Challenging Mission Phases Egress & Surface Operations

10 Video by Dan Mass

11 Opportunity at Meridiani Planum 2000 km Meridiani Gusev

12 Hematite: Mineralogic Beacon 5 o N Hematite Distribution Map from Tes Data 0 6 o S o 10 W 0% 15% hematite 0 2 o E (Figure based on Christensen et al., (2001) JGR, v. 106(E10), Plate 2, p.23,877.)

13 Meridiani Landing Site

14 Hole in One Eagle Crater

15 Backshell and Parachute Backshell and Parachute

16 You are here You are here

17 A Martian Eclipse

18 Height Above Surface (km) Short-Timescale Temperature Excursions Red = hot Purple = cold Red to purple is 2 K (degrees Kelvin) Minutes past 1000 hours (sol 12) Largest temperature variations confined to lowest 100 meters or so Appears that temperature perturbations propagate upward

19 Dust Devils Dust Devils

20 Spirit: View from Lander 5 metres Opportunity: View from Lander 5 metres

21 The first rock investigated by Opportunity

22 Schematic representation of the Mössbauer Spectrometer

23 Mössbauer Spectrum of El Capitan: Meridiani Planum Jarosite: (K, Na, X +1 )Fe 3 (SO 4 ) (OH) 6 Mössbauer Spectrum of El Capitan

24 Rio Tinto, Spain Andy Knoll

25 Spherules Spherules 5 mm

26 The Berry Bowl

27 Mössbauer on the Berry Bowl

28 Sediment Bedforms (e.g. Ripples) Sediment Bedforms

29 Ancient Terrestrial Ripples: 1.4 Billion Years Old Ancient Terrestrial Ripples

30 Ripple Cross-Bedding in 3D Ripple Cross-Bedding in 3-D

31 Mean flow velocity (m sec -1 ) Bedforms in Flowing Water 2.0 Antidunes Upper Plane Beds Dunes Lower Plane Beds Bedforms in Flowing Water 0.2 Ripples No Sediment Movement V. Fine Sand V. Coarse Sand Median grain diameter (mm) Southard and Bouchwal,1990

32 Current Ripples in Water 6 hours of ripple migration Image is 60x40 cm Current Ripples in Water Flume experiments by Dave Rubin and Jon Nelson, USGS

33 Current Ripples in Cross Section Simulation by Dave Rubin, USGS

34 Festoon Cross-Bedding on Earth Festoon Cross-Bedding on Earth

35 Festoon Cross-Bedding on Mars Festoon Cross-Bedding on Mars

36 Burns formation (Endurance crater) 2.0 m Burns formation

37 Lower Unit Lower Unit Lower Unit 7 6 Interdune/Playa Festoon Cross-lamination Wavy Bedding Translatent Strata Burns Stratigraphy 5 Whatanga Contact Zone of Recrystallization Capillary Fringe of Water Table? 4 Eolian Sand Sheet Translatent Strata Low-Angle Strata Burns Stratigraphy 3 Wellington Contact 2 Deflation Surface Water Table Controlled? 1 Eolian Dune Field Cross-Bedded Sandstone m

38 Modern Sand Dunes on Mars Modern Sand Dunes on Mars ~ 50 cm

39 Interdu ne Surfac e Interdune Surface

40 Interdune Deflation Surface Interdune Deflation Surface

41 Modern Mars Analog Modern Mars Analog: Um Asamin

42 Formation of evaporite salts

43 Modern Interdune Depression Modern Interdune Depression

44 Endurance Chemostratigraphy ~ 50 cm

45 Depth in crater Ratio to surface rock average

46 Changes Down Section: Texture Ontario Diamond Jenness

47 Meridiani environment appears to have been acidic, hypersaline, and only intermittently wet. Life exists at such extremes on Earth. But Meridiani data suggest potential challenges to origin as well as persistence of life. Rio Tinto Extremophiles Andy Knoll

48 The Good News Evidence of any life that might have existed might well be preserved in chemical sediments and concretions. Chemical and textural details of Meridiani salts and iron oxides likely to reveal much about environmental history. All this favors Meridiani Planum as a target for sample return. Andy Knoll

49 Summary Rovers have: Operated for over 1200 days Returned over 100,000 images Analyzed dozens of rocks and soils

50 Summary Evidence for water: Mössbauer detection of jarosite Crystal molds, concretions, diagenesis Festoon ripple cross-bedding Stratigraphic succession of environments

51 Summary Prospects for Life: Preservation potential is good But did life originate under such extreme conditions?

52 Dr. John Grotzinger Fletcher Jones Professor of Geology California Institute of Technology John Grotzinger is a field geologist interested in the co-evolution of surficial environments and life on Earth and Mars. His research addresses the chemical development of the early oceans and atmosphere, and the environmental context of early evolution. Field mapping studies are the starting point for more topical laboratory-based studies involving geochemical, paleontological, and geochronological techniques. Currently, his research is focused on the reconstruction of environmental conditions associated with the Cambrian radiation of animals in Oman, Namibia and Siberia. In 2004, he served as a member of both the Geology and Long Term Planning Groups for the Mars Exploration Rover mission.