Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45NSCI 314LIFE IN THE COSMOS9 - SEARCHING FOR LIFE IN OUR SOLAR SYSTEM: MARSDr. Karen KolehmainenDepartment of Physics CSUSBhttp://physics.csusb.edu/~karen/MARSDIAMETER: 53% EARTHMASS: 11% EARTHDENSITY: 3.9 gm/cm³SUNLIGHT: 43% OF EARTHTEMP: 140 TO 280 K (-130 TO 7oC OR –200 TO 45oF)ATMOSPHERE: 95% CO2, 3% N2, 2% Ar, H2O & CO2 CLOUDS, <1% OF EARTH PRESSUREWATER: POLAR ICE CAPS, SUB-SURFACE PERMAFROST(?); NO LIQUID WATER CURRENTLY, BUT LARGE AMOUNTS (?) OF LIQUID WATER ON SURFACE WHEN PLANET WAS YOUNGSURFACE: ROCKY, CRATERED, FORMER (BUT MAYBE NOT CURRENT?) GEOLOGICAL ACTIVITYJanuary 1997October 1996 March 1997SEASONS ON MARSSEASONS SIMILAR TO EARTH–MARS' AXIS IS TILTED BY 25O, ALMOST THE SAME DEGREE OF TILT AS THE EARTH'S AXIS –EACH SEASON LASTS TWICE AS LONG, SINCE THE YEAR IS TWICE AS LONGHOWEVER, UNLIKE EARTH, MARS' ORBIT IS SUBSTANTIALLY ELLIPTICAL–MARS IS CLOSER TO THE SUN IN NORTHERN HEMISPHERE WINTER, SOUTHERN HEMISPHERE SUMMER–MARS IS FARTHER FROM THE SUN IN NORTHERN HEMISPHERE SUMMER, SOUTHERN HEMISPHERE WINTER–A PLANET MOVES FASTER IN ITS ORBIT WHEN IT IS CLOSER TO THE SUNSEASONS ON MARSTHE RESULT IS:IN THE NORTHERN HEMISPHERE:–WINTER IS WARM AND SHORT–SUMMER IS COOL AND LONGIN THE SOUTHERN HEMISPHERE:–WINTER IS COLD AND LONG –SUMMER IS HOT AND SHORTREMEMBER THAT “WARM” AND “HOT” ARE USED RELATIVELY. MARS IS MUCH COLDER THAN EARTH OVERALL.IN MID-DAY ON A WARM DAY IN THE SUMMER NEAR THE EQUATOR ON MARS, THE TEMPERATURE MIGHT REACH 60OFSEASONS ON MARSPOLAR CAPS:–WATER ICE ALL YEAR ROUND–FROZEN CO2 (“DRY ICE”) IN WINTER CAP1/3 OF THE TOTAL CO2 IN THE ATMOSPHERE MOVES FROM ONE POLAR CAP TO THE OTHER POLAR CAP AS THE SEASONS CHANGE.THE RESULT IS VERY STRONG WINDS BLOWING FROM THE SUMMER POLAR CAP TO THE WINTER POLAR CAP.WINDS CAUSE HUGE DUST STORMS, WHICH OFTEN OBSCURE SURFACE DETAILS.EVIDENCE FOR LIQUID WATER ON THE SURFACE OF MARSIN THE DISTANT PAST (2-3 BILLION YEARS AGO):–DRY RIVER CHANNELS–ERODED FEATURES–PRESENCE OF CERTAIN TYPES OF ROCKS THAT COULD HAVE FORMED ONLY IN THE PRESENCE OF WATER–SALTY OCEAN?EVIDENCE FOR LIQUID WATER ON THE SURFACE OF MARSMORE RECENTLY?–SOME DRAINAGE FEATURES LOOK YOUNG AND UNERODED. IF THEY WERE OLDER, DUST SHOULD HAVE COVERED THEM UP BY NOW.–IN A FEW CASES, PHOTOGRAPHS TAKEN SEVERAL YEARS APART SHOW CHANGES.–PERHAPS THERE IS STILL SUB-SURFACE WATER, AND OCCASIONALLY A LANDSLIDE ON THE SIDE OF A CLIFF (OR SOME SIMILAR EVENT) FREES SOME WATER TO RUN OUT BRIEFLY ONTO THE SURFACE.18012060030024024030012018060060°30°0°-30°-60°180° 240° 300°0°60° 120° 180°840-4-8HISTORY OF WATER ON MARSLONG AGO, WHEN MARS HAD LIQUID WATER, IT MUST HAVE BEEN WARMER AND HAD A THICKER ATMOSPHERE (TO PREVENT WATER FROM BOILING).–ORIGINALLY MARS OUTGASSED ENOUGH CO2 FROM VOLCANOES TO HAVE 400 x AS MUCH AS IT HAS TODAY.–THIS WOULD HAVE PRODUCED A SIGNIFICANT GREENHOUSE EFFECT, WARMING MARS TO TEMPERATURES HIGH ENOUGH FOR LIQUID WATER.HISTORY OF WATER ON MARSWHAT HAPPENED TO CHANGE MARS?MOST CO2 AND H2O ESCAPED INTO SPACE–MARS IS SO LIGHT THAT ITS GRAVITY ISN'T STRONG ENOUGH TO HOLD ONTO FAST-MOVING GAS MOLECULES–SOME GAS MAY HAVE BEEN BLASTED AWAY BY IMPACTS–SOME GAS MOLECULES STRIPPED OUT OF ATMOSPHERE BY SOLAR WIND•MAGNETIC FIELD WOULD HAVE PROTECTED EARLY MARS FROM SOLAR WIND•AS MARS COOLED, CORE SOLIDIFIED AND MAGNETIC FIELD WEAKENED, ALLOWING SOLAR WIND TO GET IN–UV LIGHT FROM SUN DISSOCIATED H2O MOLECULES, H ESCAPED TO SPACE, O COMBINED WITH ROCKS (--> RUST)CHALLENGES THAT LIFE ON MARS WOULD FACEVERY LOW ATMOSPHERIC PRESSURENO LIQUID WATER ON SURFACE (ATMOSPHERE IS TOO THIN – WATER WOULD BOIL)COLDLARGE DAILY TEMPERATURE VARIATIONULTRAVIOLET BOMBARDMENT OF SURFACE (NO OZONE LAYER)MARS VIKING LANDER EXPERIMENTS: TESTS FOR LIFECARBON ASSIMILATION: MARTIAN SOIL WAS SCOOPED UP AND EXPOSED TO RADIOACTIVELY LABELED (WITH 14C) CO2 AND CO GAS (BROUGHT FROM EARTH). THEN THE SOIL WAS ANALYZED TO LOOK FOR 14C. IF THERE WERE MARTIAN ORGANISMS THAT ABSORB CO2 OR CO LIVING IN THE SOIL, THE 14C COULD HAVE GOTTEN INTO THE SOIL VIA METABOLIC PROCESSES IN THE MARTIAN ORGANISMS.•RESULTS: FOUND 14C IN SOIL, BUT…•HEAT-STERILIZED SOIL GAVE SAME RESULTS. •CAN BE EXPLAINED NON-BIOLOGICAL CHEMICAL REACTIONS.MARS VIKING LANDER EXPERIMENTS: TESTS FOR LIFEGAS EXCHANGE: MARTIAN SOIL WAS SCOOPED UP AND ADDED TO A NUTRIENT BROTH (BROUGHT FROM EARTH). THEN THE GAS ABOVE THE SOIL WAS ANALYZED FOR THE PRESENCE OF O2, CO2, N2, H2, OR CH4IF THE SOIL CONTAINED MARTIAN ORGANISMS, THEIR METABOLIC PROCESSES MAY HAVE RELEASED ONE OR MORE OF THESE GASES.–RESULTS: O2 PRODUCED, BUT… –ALSO PRODUCED WHEN DONE IN DARKNESS–ALSO PRODUCED WHEN SOIL WAS HEAT-STERILIZED–ALSO PRODUCED WHEN WATER REPLACED BROTH –CAN RESULT FROM CHEMICAL (NOT BIOLOGICAL) INTERACTION WITH WATER IN BROTHMARS VIKING LANDER EXPERIMENTS: TESTS FOR LIFELABELED RELEASE: RADIOACTIVELY LABELED (WITH 14C) NUTRIENTS WERE DRIPPED ONTO SCOOPED-UP MARTIAN SOIL. THEN THE GAS ABOVE THE SOIL WAS EXAMINED FOR THE PRESENCE OF 14C. IF THERE WERE MARTIAN ORGANISMS LIVING IN THE SOIL, THEY MIGHT HAVE ABSORBED THE NUTRIENTS AND THEN RELEASED GASES CONTAINING THE 14C.•RESULTS: FOUND 14C LABELED GAS, BUT…•CAN BE EXPLAINED BY INTERACTION OF BROTH AND PEROXIDES (NON-ORGANIC CHEMICALS) IN SOIL, PRODUCING CO2VIKING LANDER EXPERIMENTS: TESTS FOR LIFEGAS CHROMATOGRAPH - MASS SPECTROMETER MEASUREMENTS: SCOOPED-UP MARTIAN SOIL WAS BAKED UNTIL VOLATILES (EASILY VAPORIZED MATERIALS) OUTGAS. THE RESULTING GAS WAS ANALYZED, LOOKING FOR ORGANIC MOLECULES.RESULTS: NONE FOUNDBOTTOM LINE RESULTS OF ALL EXPERIMENTS: RESULTS INTERESTING, BUT INCONCLUSIVEMETHANE IN MARTIAN ATMOSPHERE?DISCOVERED BY EUROPEAN SPACECRAFT IN 2004 – VERIFICATION STILL NEEDEDMETHANE CAN BE PRODUCED BY LIFE, VOLCANOES, OR LARGE COMETARY IMPACTSMETHANE LASTS ONLY A FEW CENTURIES IN THE ATMOSPHERE –NO RECENT LARGE COMETARY IMPACT–COLD BE VOLCANIC IN ORIGIN, BUT THAT IS STILL EXCITING•CURRENT GEOLOGICAL ACTIVITY