Mars: Mars - the Fourth Rock from the Sun - Dr. Mikhail Tomoff Summer Astronomy School NAO “Rozhen”, 2004 Credit:: Ilyan Darganov Mosaic image taken by Viking. In the centre – Valles Marineris


Historical Background: Historical Background the name – (Greek: Ares) – the Roman god M. was god of agriculture before becoming associated with the Greek god of war Galileo; Huygens – Syrtis Major 1659, 1672, Cosmotheros ; Cassini 1699 – rotational period; First Surface Features Determined: the 1700s Miraldi –- the poles, 1719 – great opposition nearly as close as the one in 2003 Sir William Herschel – the color changes, believed in life on all solar bodies The 1800s: The mapping of Mars Giovanni Schiaparelli (1835-1910) – nomenclature for Mars features from mythology, “canali” Percival Lowell – believed in intelligent life on Mars, “channels” 20th and 21st century atmospheric observations Gerard Kuiper 1952 – CO2 the missions continuing until recent days


Slide4: Schiaparelli’s map of Mars


General Facts about …: Physical features (orbital and other) Mass (kg) 6.421.1023 , Mass (Earth = 1)1.0745.10-1 Equatorial radius (km)3,397.2 Equatorial radius (Earth = 1) 5.3264 .10-1 Mean density (gm/cm 3) 3.94 Mean distance from the Sun (km) 227,940,000 Mean distance from the Sun (Earth = 1) 1.5237 Rotational period (hours) 24.6229, Rotational period (days) 1.025957 Orbital period (days) 686.98, Mean orbital velocity (km/sec) 24.13 Orbital eccentricity 0.0934 Tilt of axis (degrees) 25.19 Orbital inclination (degrees) 1.850 Equatorial surface gravity (m/sec2) 3.72 Equatorial escape velocity (km/sec) 5.02 Visual geometric albedo 0.15 , Magnitude (Vo) -2.01 (varies!) 2 moons – Phobos and Deimos General Facts about …


Slide6: Atmosphere – quite different than the Earth’s one 1 percent of Earth's atmosphere ! Carbon Dioxide (CO2): 95.32% Nitrogen (N2): 2.7% Argon (Ar): 1.6% Oxygen (O2): 0.13% Water (H2O): 0.03% - small amounts but enough for cloud’s formation Neon (Ne): 0.00025 % Temperature and Pressure T - average -63° C (-81° F) , max. 20° C (68° F) , min. -140° C (-220° F) pressure - average – 7 millibars (varies with seasons) Climate significantly elliptical orbit – big temperature variations dramatic weather changes, strongly variable atmosphere global dust storms clouds – often more cloudy than dusty (HST, NRAO) perihelion climate (summer in S. H.)– dust storms – Viking, Mariner 9, NRAO aphelion climate - planet-wide belts of water ice clouds (not identified by the 1970’s spacecrafts)


Slide7: Geology Southern H. higher than the North with elevation border between Internal structure – dense core (iron and sulfur) , mantle, thin crust (80 km S.H., 35 N.H.) No active tectonic plates Active volcanoes in the past, no evidence of current activity Erosion patterns – may be water, may be not Weak magnetic field Large but not global magnetic fields in some regions - MGS


Missions’ history: Missions’ history The past missions Mariner IV – the first successful mission Mars 2 – first landing on Mars Viking 1976. The primary mission objectives were to obtain high resolution images of the Martian surface, characterize the structure and composition of the atmosphere and surface, and search for evidence of life. The Viking Landers transmitted images of the surface, took surface samples and analyzed them for composition and signs of life, studied atmospheric composition and meteorology, and deployed seismometers. Last transmits – 1980 and 1982. The results from the Viking experiments give our most complete view of Mars to date Mars Pathfinder - landed on 4 of July 1997 (20 years hiatus!) 11 October 1964 – Mariner IV on the top of the rocket Atlas - Agena September 9, 1975 – launch of the Viking 2


Slide9: Viking 1 lander site - image of basalt type of rock


Slide10: Viking 2 lander site - image of regolith


Slide11: Recent missions MER – Spirit (Gusev crater and Columbia Hills) and Opportunity Hematite found in Planum Meridianum – may be of origin that includes water presence Beagle (lost) and Mars Express, orbiting the planet HRSC, OMEGA, PFS, SPICAM, ASPERA, MaRS Mars Global Surveyor – scientific researches 2001 Mars Odyssey spacecraft – recently - full martian year celebration during which it has shown us where water ice lies buried beneath the surface; analysed "what Mars is made of" by identifying minerals and chemical elements; and, studied the martian radiation environment to help us understand potential health effects on future human explorers.


Future missions and Colonization: Future missions and Colonization Future launches - Mars Reconnaissance Orbiter , Phoenix , Mars Science Laboratory Colonization ideas – Mars Society – dr. Zubrin, desert and polar experiments Mars – future goal for human mission after the Moon 1989 – the Ninety days plan – lunar bases, orbital hangars, space docks, transportation fleets, spacecraft – $450 billion dollars! - REJECTED! Reason for the high price – construction of a massive spacecraft 1990 – Mars Direct plan (dr. R. Zubrin) – a trip without the 320 tones of propellant; price - $20 billions dollars “Mars in situ propellant production” – H2+CO2CH3+H20, H20 H2+ O2 , the methane and oxygen are powerful rocket propellant Why not nuclear fusion? – not enough researched – why? – … 1st launch – ERV (Earth Return Vehicle) – unmanned payload – 20 t H2 , chemical unit, atmospheric compressor, rover 2nd launch – manned spacecraft + ERV


Slide13: The habitation – exercise room, sleeping quarters, bathroom, laboratory, galley, lounge, digital library 600+500+600 days Mars Society's experiments – desert and arctic “Martian” bases Testing technology for life support, transportation, recycling etc. Inflatable greenhouse Energy production – solar cells arrays Other problems before a human mission to Mars: Radiation hazard Low gravity – muscle and bone’s deterioration Psychological stress – “cabin fever” Dust storms No possibilities for rescue missions if s.th. goes wrong. What will the humans do on the Red planet Study geology, look for water, take samples to return to Earth Mars Station – Bulgarian educational project Life issues – Mars meteorite story 1996 David McKay, recent findings – some non-biological processes could produce the patterns found in the meteorite, the big speculations, the need of sample return mission


Observable Mars: Observable Mars Small guide to observing Mars The great oppositions – great opportunities – Mars is about 25 arcsec. The difference between what we see (albedo features) and the real landscape. Different colors – different types of lands. Dark color of the areas with impact craters filled with sand size dust particles Main features – Syrtis Major, Polar Caps, clouds, global dust storms, Hellas Visual observations, drawings and astroimages


Hubble Space Telescope images: Hubble Space Telescope images The most breathtaking and astonishing images ever taken from Earth Examples :


Slide17: Made with WFPC 2 Valles Marineris 4000 km canyons Olympus Mons 3 times higher than Mount Everest Size of Arizona Tharsis Bulge Solis Lacus The Eye of Mars Terra Sirenum Impact craters South Polar Cap Carbon dioxide and water ice Dust activity streaks N.H. – home of volcanoes, S. H. – place of impact craters


Slide19: The two faces of Mars Syrtis Major and Hellas Basin in the left image The right image – see previous slide


Marsoweb site: Marsoweb site Opportunity for the general public to take place in the scientific research of Mars


More info in the Net (Bibliography): More info in the Net (Bibliography) NASA’s sites – Mars Exploration Program – with tones of images Mars Today – news and articles about the planet every day Red Colony Mars Society Marsoweb – invitation to participate in science research Nine Planets – general information of Mars with a lot of useful links Solar Views - general information of Mars with a lot of useful links