- Mars: Closest Approach 2007 Mars Elena Zhang and Karen Tekverk

Background Information Mass: 6.42 x kg or 0.11 Earths Distance from Sun: AU Radius: 3390 km or 0.53 Earth radii Average density: 3.93 g/cm x Earth’s gravity at surface 0.006x Earth’s atmosphere at surface Atmospheric composition: – 95.3% CO 2 – 2.7% N 2 – 1.6% Ar – 0.4% other - Mars (Adapted from Planets and Life Table 18.1, page 358)

Background Information Dense core of indeterminate size – either small dense Fe core, or larger less dense FeS core No global-scale plate tectonics, but some tectonic processes – volcanism (Tharsis), grabens and faults (Valles Marineris) Evidence for liquid water on ancient Mars surface There are a few dozen Martian meteorites that have landed on the Earth, know collectively as SNC meteorites, and ALH84001 Composition of Martian crust (from Viking analysis): – 43.4% SiO 2 – 18.2% Fe 2 O 3 – 7.2% Al 2 O 3 – 7.2% SO 3 – 6.0% MgO – 5.8% CaO – 1.34% Na 2 O – ~3% other - Mars

Mars Flyover First shown: South Pole Three linear volcanoes: Tharsis Rise North Pole Largest volcano: Olympus Mons Valles Marineris Colors illustrate 22 km of altitudinal variation – blue is the lowest - Mars Flyover based on MOLA Data for the Carl Sagan Lecture, NASA/Goddard Space Flight Center Scientific Visualization Studio

Previous Exploration Viking 1 and 2, 1975, first to land on surface and take images Mars Observer, 1992, orbiter Climate Orbiter, 1998, weather satellite Polar Lander / Deep Space 2, 1999, lost on arrival Planets and Life, page 358 Landmarks and Other Spacecraft

Current Missions Pheonix Launch: Aug 4, 2007 Arrival: May 25, 2008 Dig up and analyze icy soil at north polar region Mars Reconnaissance Orbiter Launch: Aug Arrival: Mar. 10, 2006 Telescopic camera Mars Exploration Rovers Spirit Lauch: Jun 10, 2003 – Arrival: Jan 3, 2004 Opportunity Launch: Jul 7, 2003 – Arrival: Jan 24, 2004 Search for evidence of liquid water Mars Express Launch: Jun 2, 2003 Arrival: Dec 2003 Explore atmosphere and surface from polar orbit Mars Odyssey Launch: Apr 7, 2001 Arrival: Oct 24, 2001 Orbiting spacecraft, determine composition of surface, detect water and shallow buried ice, study radiation environment

Future Missions Mars Science Laboratory Launch: Fall 2011 Arrival: 2012 Curiosity Rover, 2x long, 3x heavy as previous rovers Over $2.5 billion Collect soil samples, rock cores, analyze for organic compounds and environmental conditions that could have supported microbial life Mars Atmosphere and Volatile Evolution (MAVEN) Launch 2013 Arrival: 2014 Atmosphere, climate history, potential habitability

Previous Claims of Life on Mars Two Types of Round Pebbles in ‘Endurance’, NASA/JPL/Cornell html - Mars Then And Now “Canals” (so named by Percival Lowell) Blueberries (actually hematite spherules) Crinoids (actually water features) “The Couch” - Terrain and rock “Couch”

Characteristics of Planetary Life Elemental building blocks of life – C, H, O, N… Molecular building blocks of life – amino acids, sugars Life begins to exist quickly after it becomes possible Environmental requirements for life straightforward and widespread Almost any geologically active planet could foster life, including Mars

Previous Evidence for Martian Life Spirit Rover Comanche rock outcrop rich in carbonates found in Gusev Crater Could be due to aqueous processes, or volcanic activity - MOLA-based Flyover of Gusev Crater, NASA/Goddard Space Flight Center Scientific Visualization Studio

Previous Evidence for Martian Life Spirit Rover Stratified soil layers with different compositions Snow melt might have carried soluble minerals (ferric sulfate) lower than less soluble minerals (hematite, silica, gypsum) - Sprit Stuck in Soft Soil as Engineers Devise Methods to Free Spirit

Previous Evidence for Martian Life Methane gas identified in Active hot spots of methane Chemical processes rapidly destroy methane (oxidizing agents) Source: could be geology (water and rock) or biology Next step: test abundance of molecular trace species, isotopic analysis (MSL)

Previous Evidence for Martian Life 300 billion year old deposits of hydrated silica found on volcanic cone (by Mars Recon Orbiter) Silica can be transported, dissolved, and concentrated by hot water or steam Indicates possible hydrothermal environment (hot spring)

Cost of Current Missions Phoenix $325 million Mars Reconnaissance Orbiter Total cost: $720 million Cost of spacecraft and science instruments: $450 million Launch: $90 million Mission operations: $180 million Mars Exploration Rovers Total cost of building, launching, landing, and operating for initial 90-day mission: $820 million Four mission extensions = $104 million Fifth mission extension = at least $20 million Mars Express Total cost: About $369 million Orbiter: About $179 million Lander: About $95.5 million Mars Odyssey Total cost: About $300 million Development and construction: $165 million Launch: $53 million Operations: $79 million - Mars Odyssey Seen by Mars Global Surveyor, NASA/JPL/MSSS

NASA’s Proposed Budget for 2012 (in millions of dollars) Mars Science Lab MAVEN Other missions and data analysis Total Mars Exploration Total NASA budget18,724.3

Our Proposed Budget For an orbiter and rover (there and back): Approximately $2.7 billion About 14% of NASA’s total 2012 budget (or, for reference, about 0.4% of Department of Defense’s 2011 budget) Ways to cut costs: » Wait for a return on information from the Mars Science Laboratory, designed to give a better background on how and where life might have existed on Mars » Allow for contractors to have rights to anything patented in the process - The Beagle 2 lander, ESA