MARS - THE RED PLANET - DR. YASSER M. ABDOU PHD IN EXPERIMENTAL NEUTRINO ASTROPHYSICS
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Film & Radio Radio : Tuning in Mars Below are some of the films to look for in your video store: Movie Title Year John Carter 2012 Mars Needs Moms 2011 Princess of Mars 2009 War of the Worlds 2 2008 Martian Child 2007 Doom 2005 War of the Worlds 2005 …................ …..... Flash Gordon: Mars Attacks the World 1938 Aelita: Queen of Mars 1924 5
MARS FOURTH PLANET FROM THE SUN NAMED AFTER THE ROMAN GOD OF WAR DESCRIBED AS THE “RED PLANET” THE IRON OXIDE PREVALENT ON ITS SURFACE GIVES IT A REDDISH APPEARANCE A TERRESTRIAL PLANET WITH A THIN ATMOSPHERE
MARS FACTS DISTANCE FROM SUN ≈1.52 TIMES AS FAR AS EARTH TIME TO ORBIT THE SUN ~ 26 EARTH MONTHS ATMOSPHERE ~ MOSTLY CARBON DIOXIDE MARTIAN DAY ~ 24.7 HOURS TEMPERATURE ON THE PLANET’S SURFACE HARDLY RISES ABOVE FREEZING POINT
EARTH AND MARS | COMPARISON PARTICULARS EARTH MARS RADIUS 6378 KM 3397 KM DENSITY 5515 KG/M3 3933 KG/M3 GRAVITY 9.8 M/S2 3.72 M/S2 YEAR 365.25 DAYS 686.98 DAYS ECCENTRICITY 0.017 0.094 DAY 24 HOURS 24 HR 39 MIN OBLIQUITY 23.45º 25.19º
MARS | SURFACE FEATURES SURFACE COLOR “RED” FEATURES IMPACT CRATERS LARGEST VOLCANO IN THE SOLAR SYSTEM (OLYMPUS MONS) LARGEST CANYON IN THE SOLAR SYSTEM VALLES MARINERIS (VALLES MARINERIS) ANCIENT RIVER CHANNELS LAVA ROCKS DUST: REDDISH FROM VOLCANIC ROCK
MARS | ATMOSPHERE UNBREATHABLE THIN DUSTY, MAKES THE SKY PINKISH, LOTS OF DUST STORMS SURFACE PRESSURE: 1/150TH OF EARTH’S (ONLY 5.6 MILLIBARS) COMPOSITION: 95% CO2, 3% N, 1.5% AR, 0.1% O2, 0.03% H2O
MOONS OF MARS PHOBOS MARS HAS TWO TINY MOONS NAMED “DEIMOS” (PANIC) & “PHOBOS” (FEAR) Deimos THE MOONS ARE IRREGULAR AND VERY SMALL IN SIZE PHOBOS 27X22X18 KM DEIMOS 15X12X10 KM THE MOONS ARE PROBABLY ASTEROIDS CAPTURED BY MARS
WATER ON MARS WATER IS THE KEY TO LIFE AS WE KNOW IT THE NORTH AND SOUTH POLES OF MARS ARE COVERED WITH THICK ICE OR FROST SOME ASTRONOMERS ABOUT 100 YEARS AGO THOUGHT THERE WERE CANALS ON MARS DUG BY INTELLIGENT CIVILIZATION SPACE PROBES TO DATE HAVE NOT FOUND ANY TRACES OF CANALS ON MARS
IMPACT CRATERS ON MARS IMPACT CRATER IN MARS IS A LARGE HOLE IN THE GROUND CAUSED BY A METEORITE SMASHING INTO THE SURFACE OF MARS EVERY SOLID BODY IN THE SOLAR SYSTEM SUFFERS FROM THE EFFECTS OF IMPACT CRATERING THE PROJECTILES THAT CAUSE IMPACT CRATERS, TRAVEL AT VERY HIGH SPEED AND FASTER
REASON FOR OCCURRENCE OF IMPACT CRATERS ON MARS FORMED BY A LARGE OBJECT SUCH AS AN ASTEROID OR A COMET WHEN THESE LARGE OBJECTS HIT THE SURFACE THEY FORM HOLES (CRATERS) LATE HEAVY BOMBARDMENT PERIOD OF OUR SOLAR SYSTEM NO ATMOSPHERE TO PROTECT IT FROM ASTEROIDS THAT'S WHY MARS HAS CRATERS
PHOTOGRAPHS OF VARIOUS IMPACT CRATERS ON MARS
CONTD…
Why was Mars warmer and wetter in the past? Mars’s atmosphere must once have been much thicker with a much stronger greenhouse effect, though we do not yet know whether this made Mars warm and wet for an extended period of time or only intermittently.
Why did Mars change? Change must have occurred due to loss of atmospheric gas, which weakened the greenhouse effect. Some gas was probably blasted away by impacts, but more probably was stripped away by the solar wind as Mars cooled and lost its magnetic field and protective magnetosphere. Water was probably also lost because ultraviolet light could break apart water molecules in the atmosphere, and the lightweight hydrogen then escaped to space.
Seeking Life on Mars 21
Astrobiological Space Missions Flyby(goes past a world just once and then continues on its way.) – The craft flies by the destination; – Relatively easily accomplished; – Voyager, Pioneer 10 & 11 – Orbiter – The craft enters into an orbit around the object; – allowing longer-term observation during its repeated orbits – More difficult to achieve; – Galileo (to Jupiter). – Lander – A (usually) soft landing is intended; – Considerable deceleration must be achieved; – Phoenix, Mars rovers. – Sample & return – Samples are obtained and returned to Earth; – Extremely difficult; – Often financially draining, but politically popular; – e.g. Apollo, Luna
Past 23
Present 24
Future 25
Other places on Earth that can help us understand Mars include: Death Valley, California, where Ubehebe crater and "Mars Hill" have geologic features similar to those on Mars Mono Lake, California, which is a 700,000-year-old evaporative lake that compares to Gusev Crater, a basin on Mars where water once was likely Channeled Scabland in Washington, where catastrophic floods swept through the land much like what happened long ago in the Ares Vallis flood plain where Mars Pathfinder landed Permafrost in Siberia, Alaska and Antarctica, where subsurface water-ice and small life forms exist Volcanoes in Hawaii, which are like those on Mars, though much smaller 26
Three key requirements for life 1. Source of molecules (easily accomplished) – The biologically important atoms C, H, O, N are universal; – Amino acids are also available in the environment; – Amino acids are easily manufactured (Miller Experiment). 2. Source of energy (a little more difficult) – Solar radiation (drops with inverse square law); – Chemical reaction rates drop by a factor of 2 for each 10ºC drop; – Hydrothermal vents; – Other exotic energy sources. 3. Liquid water (a key limitation) – Water transports nutrients in, and toxic wastes out; – Water expands when it freezes; – Water is liquid over a very wide range of temperatures.
Is Mars habitable? Mars almost certainly had a habitable surface during its wet periods more than 2–3 billion years ago. Its surface or near-surface might still sometimes be habitable when its axis tilt is greater than it is now, and the subsurface may still have habitable regions today. 28
Three lines of evidence 1. Gas emissions; 2. Martian meteorites; 3. Viking. 29
Evidence: Methane on Mars Five sources for this gas: Cometary impact—extremely unlikely for methane. Human contamination—ruled out by spatial resolution, and the timing of the discovery. Volcanism—not seen, but such energy sources would be fabulous for life. Weird geological or chemical reactions??? Life itself! 30
Evidence: Martian Meteorites In 1984, an expedition to the Allan Hills region of Antarctica picked up a 1.9 kg rock, thereafter called ALH84001. Isotopic ratios of 16O, 17O, 18O show this is not an Earth rock. These isotopic ratios strongly imply it is not an asteroidal chunk, or a piece of the Moon, either. Gas samples trapped in the rock are consistent with it being a chunk of Mars. Only 34 Martian meteorites have been found. 31
ALH84001 history 4.5 b.y.a. The parent rock solidified from molten material. (The southern highlands are suspected as the meteorite’s origin—spectroscopy matches with Eos Chasma in Valles Marineris.) 4-4.5 b.y.a. Heavy bombardment shocks occurred near the parent rock. (The meteorite contains characteristic shock structure). 3.9 b.y.a. Liquid water seeped into the rock, leaving behind carbonate grains 0.1-0.2mm in diameter. (From radiometry of minerals in the fractures.) 16 m.y.a. The rock was blasted into space to drift. (Based upon cosmic ray exposure.) 13,000 y.a. The meteorite impacted Antarctica. (Based on the age of ice layers at Allan Hills.) 1984 ALH84001 was found by humans during a meteor-hunting expedition. 32
Is there evidence of life in martian meteorites? Evidence have been presented as suggesting the presence of past life in a martian meteorite, but each also has a potential nonbiological explanation. 33
Viking Viking results In 1976, two probes to Mars carried basic biological labs to look for life on Mars. The Viking probes were equipped with robotic arms that could scoop out Martian soil and bring it on board for analysis. The number one priority: search for evidence of life! 34
Viking 35
Viking Biology Experiments Labeled release experiment, looked for signs of metabolism Pyrolytic release experiment, looked for signs of photosynthesis Gas exchange experiment, looked for signs of respiration
Is there any evidence of life on Mars? The Viking experiments produced results that some scientists think may be evidence of life, but nonbiological explanations seem more likely. Recent observations have detected methane in the atmosphere, which may be due to life or may simply be due to volcanism. Overall, there are some possible hints of life on Mars, but no definitive evidence. 37
Human Settlement on Mars Aime: Send humans to Mars and to sustain life there.
Mars Websites ● http://mars.jpl.nasa.gov/classroom ● http://mars.jpl.nasa.gov ● http://marsed.asu.edu ● http://msip.asu.edu ● http://marsbound.asu.edu
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