CLIMATE GEOLOGY HUMAN. Common Thread W A T E R. Determine if Life Ever Arose on Mars. Characterize. the Climate. Characterize.

Transcription

1 Exploring Mars: The Phoenix Mission John Moores August 2, 2008

2 Who I am John Moores University of Arizona Doctoral Candidate in Planetary Sciences Part of the Canadian and American science teams My role Strategic Science Planner or SSP Surface Stereo Imager (SSI) / Atmospheric Science Theme Group (ASTG) liason

3 What is Phoenix Quick Facts Small sized (~$400M) NASA mission led by the University of Arizona s Lunar and Planetary Laboratory Principal Investigator: Peter Smith Several Firsts First mission to visit the Martian Arctic First landed mission to be controlled from a university Today is sol 68 or the 68 th martian day of the 90-sol primary mission

4 Why did we go to Mars? An amazing finding from another U of A instrument several years ago The Gamma Ray Spectrometer onboard Mars Odyssey saw the signatures of water hidden just below the surface We are following up on their discovery

5 What are we doing on Mars? Common Thread W A T E R Characterize the Climate Prepare for Human Exploration Determine if Life Ever Arose on Mars Characterize the Geology LIFE CLIMATE GEOLOGY HUMAN

6 Translated into specific tasks Phoenix is tasked with assessing the habitability (past & present) of the Martian Arctic Confirming the presence of Water Determining if there are any organic materials in the soil or ice table Determining the chemical composition of the soil Phoenix also is assessing the polar climate Daily measurements of winds, clouds, dust with a sophisticated instrument package

7 Part 1 Overview Martian Backgrounder: what makes the red planet so intriguing? Past exploration initiatives. Part 2 The Phoenix mission from concept through construction, liftoff & landed operations Part 3 Living and working on Mars How we control the Lander Part 4 Results to date and the future of Martian Exploration

8 Part I What makes Mars so Intriguing? & Past Exploration Initiatives.

9 Mars Quick Facts The 4 th planet from the sun at 1.52 AU The 3 rd largest rocky (terrestrial) planet in the solar system with an equatorial radius of 3402 km (3000 km smaller then Earth) 1/3 rd the earth s surface gravity Eccentric orbit (0.09 compared to 0.01 for Earth) is as important as the planet s tilt in causing seasons 2 small captured asteroid moons phobos and deimos Distinctive reddish color from rusted iron compounds Geologically very active in the past home of the solar system s largest volcano (Olympus Mons) and largest canyon (Valles Marineras) Posesses surface water in polar ice caps which may have flowed in ancient times The most clement body in the solar system (after the Earth) for supporting life as we know it

10 Mars through History Visible to the naked eye and known to early astronomers Red color earned it the title of god of war for the greeks and romans Helped Kepler derive his laws of planetary motion in 1609 The large eccentricity could not be reconciled with circular orbits By the late 1800s telescopes were powerful enough to observe surface features Giovanni Schiaparelli observed the 1877 martian oposition and Percival Lowell began his observations in Flagstaff in 1893 Saw evidence for Martian life and civilization The Canals and Oases of Mars A large greenish bluish triangular feature (Syrtis Major) thought to be plant life Not all astronomers could distinguish or agree on what was being seen

11 The Canals From The Decline and Fall of the Martian Empire by Kevin Zahnle (2001) in Nature ( journal/ v41 2/ n6843/full/412209a0.htm l )

12 Mars through History In Reality there were no canals and no vegetation. Just optical illusions due to the difficulties of telescopic observations However, without better data, Mars remained largely a mystery until robotic exploration of the 1960s and 1970s Best view from HST. Taken in 1995 during Martian Spring

13 Modern Exploration How do you explore a Planet? Cannot just travel to the planet and orbit or land 3 steps: Step 1: fly-by missions Mariner 4 (1964) Mariner 6&7 (1969) Step 2: Orbiting missions Mariner 9 (1971) Viking (1975) Mars Global Surveyor (1997) Mars Odyssey (2001) Mars Reconnaissance Orbiter (2005) Image Credits: MARINERS 4 and 9/VIKING O1: Goddard Space Flight Center (NASA) MGS: Jet Propulsion Lab (NASA) MARS EXPRESS European Space Agency (ESA)

14 Modern Exploration Step 3 Landers & Rovers Viking landers 1&2 (1975) First Landing, Search for Life Mars Pathfinder (1997) Return to the red planet and first rover (Sojourner) Spirit and Opportunity rovers (2003) Follow the Water

15 And of course, Phoenix

16

17 Modern Exploration What are Orbiters good for? Orbiters can characterize the entire surface of a planet Good for identifying large features and regional differences Good for watching how these features change with time (including weather) Good for making maps What are Landers good for? Good for analyzing the surface in fine detail More accurate Minerology, Chemistry, small scale features The Human Perspective of small-scale scale variations Are important to calibrate the maps made by orbiters What are Rovers good for? The landing site may not be the most interesting or scientifically useful area to investigate Can examine several different areas in fine detail

18 Modern Exploration Mars has been a hard target to explore MARS 20 EARTH 20

19 A Photo Tour of the Red Planet Slides illustrated with the aid of NASA Worldwind Available from:

20 What we came to see and investigate! Mars is a land of extremes, but is comprehensible on a human level in a way other planetary bodies are not

21 Atmosphere Why does the sky look Red? There are many very fine dust particles suspended in the atmosphere which scatter red light How do these dust particles get suspended? Dust Storms Occur on a yearly basis at the start of Southern Summer May last up to several years and can become global in extent Dust Devils Suction fine particles off the surface

22 Dust Devils Compared to their terrestrial counterparts, martian dust devils are: Very large (several hundred meters across) Have very tall plumes (up to several km tall) Very common Tracks are easily seen from Orbit Both Pathfinder and MER have observed several plumes

23 Seasons on Mars Two effects are important: the tilt of the planet (25.4, similar to that of the Earth) the distance between Mars and the Sun Also, since Carbon Dioxide is already near the freezing point at martian temperatures, the atmosphere can freeze out on the winter pole

24 Ice Caps There are solid water ice caps at both poles Northern cap is much Larger then the southern cap Both caps are dissected by spiral troughs Not well understood what causes the spiral pattern Thought to be some kind of interplay between sun and sublimation of ice Troughs are composed of layers Each cap has a permanent and Seasonal component Permanent cap is water ice Seasonal cap is frozen Carbon Dioxide 3km

25 Ground Ice & Patterned Ground There is a great deal of ice off the cap, especially in the Northern Lowlands detected by Mars Odyssey This ice is frozen throughout the martian year leading to a condition in the soil known as permafrost Leads to the formation of Ice Wedge Polygons: Contracting ice cracks Cracks infill with more water (or dust) Crack location from the previous year is a weak spot and re-cracks the next year The process repeats Image from Hi-Rise Camera, Diagrams from US Army Corps of Engineers

26 Dunes Located in isolated fields and in large sand seas around the polar caps Not clear what material forms the dunes On earth, wind-blown sand is mostly quartz Mars appears to be quartz- poor Cemented Clays? 3km

27 Evidence of Past Water Fly-By Missions saw only craters, but the first orbiters (Mariner IX and Viking Orbiters) saw dry riverbeds

28 Evidence of Past Water Streamlined Islands and outflow channels are observed near valles marineras Streamlined islands indicate the direction of flow Chaos regions indicate where groundwater reservoirs have collapsed Scale of outflow features indicate that the scale of water release must have been extremely large Similar features seen in Washington State

29 Evidence of Past Water River Deltas and meanders seen by Mars Global Surveyor Indicates that liquid water existed over a long period of time (requires a mature river system to form a delta) Indicates that there were some larger bodies of water for rivers to empty into

30 Part II The Phoenix Mission, from concept through construction, launch, landing and landed operations.

31 The NASA Scout Program and Phoenix Concept Scouts were designed to be relatively low-cost and innovative complements to NASA s Mars Exploration Program. The Phoenix Mission won the competitive bid process in 2003 with partners including JPL, CSA, Lockheed Martin, and multiple universities. The Phoenix Concept was simple: use existing hardware put in storage after Mars Polar Lander Crashed and put new instruments onboard High Risk, but potentially high reward

32 How Phoenix Fits into the Broad Scheme of Mars Exploration

33 The Spacecraft

34 Phoenix at Lockheed Martin

35 Meet the Phoenix Instrument Family

36 Surface Stereo Imager (SSI) Captures images in 24 filters, 12 in each eye Compare this to RGB images captured by a modern digital camera

37 Robotic Arm

38 Robotic Arm Camera (RAC) Built to image the contents of the Scoop (Left) But Wide Field of View and mounting allow for a larger set of targets then the SSI

39 LIDAR and MET

40 Thermal Evolved Gas Analyzer (TEGA) U of A designed oven & mass spectrometer pair, looks at composition of the soil by watching how they break down and turn to gas as the temperature ramps up past 1000 C

41 Microscopy, and Electro Chemistry and Conductivity Analyzer (MECA) A complicated experiment designed to hydrate the martian soil and observe the chemical reactions that occur. Also contains two microscopes and a probe

42 The Launch! Phoenix Launched on a ULA (United Launch Alliance) Delta- 2 rocket from Cape Canaveral Air Force Station on August 4, 2007 at 5:26 am ET.

43 After the launch

44 Off to Mars! km 60 Phoenix VL2 30 Latitude 0 VL1 MPF Opportunity Spirit East Longitude

45 The Seven Minutes of Terror The Phoenix Lander must slow from interplanetary speeds (measured in miles per second) to a full stop in only seven minutes! Referred to as EDL for Entry Descent and Landing, This is the most dangerous time for any landed spacecraft

46 Another First, courtesy of U of A s HiRISE camera

47 A Bird s Eye View of the Landing Site

48 Here we are!

49 Part III Living and Working on Mars & How we control and command the spacecraft

50 The Science Operations Center Located at 6 th AVE and Drachman Open to the public on Wednesdays ( phoenix.lpl.arizona.edu for more information!)

51 Payload Interoperability Testbed When there are questions about something we re about to try on Mars we can simulate it on earth first in the PIT

52 Practice Makes Perfect For months prior to landing we perfected how the science operations team worked together For these tests, the PIT was also used to simulate Mars

53 Communicating with Phoenix

54 How to drive a Mars lander More complicated then the claw machine Phoenix must be autonomous due to the light time delay It s an involved process that takes two martian days or sols to complete from start to finish, under ideal conditions Half the team at any one time is working on the plan for the next day and the other half on the day afterwards Data from Phoenix Strategic Plan Tactical Plan Data from Phoenix Strategic Plan Tactical Plan

55 Working on Mars Time We plan during the Martian night, after the results from the current day have come back to earth. At the end of the night we uplink or radiate the instructions for the next day But, the martian day is 24 hours and 39 minutes long, so to stay in sync, the shift starts on average 39 minutes later every day. Think of it like experiencing continual jetlag Some people adapt better then others Eventually, every 37 days or so, we make a complete circuit of the clock

56 Part IV Results collected to date & The Future of Martian Exploration

57 That first glimpse At Right, -> Phoenix s first view of the Martian Arctic <- At left, Huygen s first view of the surface of Titan (from my first mission)

58 Water Ice Found! Chips of white stuff broken off the permafrost layer sublimate away in a few days Very suggestive result! 40 sols later, the TEGA mass spectrometer confirms that the white stuff is water ice

59 Winds on Mars Movies and the Wind Telltale show the movement clearly

60 Getting our hands dirty on Mars

61 Getting a close look at Martian Dust

62 The LIDAR beam probing the martian night

63 The Midnight Sun on Mars

64 The rest of the mission We have been extended out to sol 120 Lots of work left to do, many TEGA and MECA cells left to fill, analyses to be made And who knows what we will uncover in the next trench?

65 Life on Mars? Could life have been present on Mars in the past? Early Mars likely possessed liquid water and similar quantities of most chemical compounds found on the early earth. Mars may have cooled more quickly then the earth due to its smaller size, thus simple life may have arisen there earlier then on the Earth An ancient martian meteorite recovered from Antarctica, ALH84001 shows fossilized life- like structures in carbon globules There are many processes that can produce such structures, not all of them biological Structures also seem small, tubes at right are 50nm across

66 Life on Mars? Could Mars support life today? The surface of Mars is extremely hostile to life as we know it Extreme levels of UV irradiation Oxidizing chemicals Extremely dry Extremely cold Large temperature difference between night and day However, there are terrestrial organisms which can exist in environments that would kill a human being - Extremophiles There are also limited martian environments which improve one or more of these factors, such as ground-ice rich regions Bottom Line: still an open question

67 Missing Organics Organic materials are a signature of life past or present The Viking lander could not find evidence for organics A perplexing result as organics naturally infall on any planetary body Studies in the Atacama desert in Chile suggest that Viking s instruments may have not known how to look for the signature A question that may be being answered as we speak! TEGA should have just finished running a test for organics on the icy layer, stay tuned for results!

68 Mars Future Exploration

69 Mars Science Laboratory MSL is a NASA Flagship Mission planned for launch on Sept 15, 2009 Much larger and more mobile then the MERs The first long distance martian rover (up to 20km at up to 90m/hr) First nuclear-powered rover (planned) Designed to examine habitability Meant to have similar capabilities of a terrestrial sample analysis lab

70 Human Exploration Manned Exploration? In the wake of the success of MER in 2004 President Bush announced a new focus for NASA The Moon-Mars Mars initiative calls for Mars to be the next target for manned exploration following the return to the moon in Several Groups promote the exploration of Mars in the short term Most notable: The Mars Society Argue that the technology is presently available and economical Artist s Conception of a Martian Prospector Jet Propulsion Laboratory (NASA)