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Old Mars

Old Mars. Mars is further away, we see a smaller image so we need much better telescopes. Mars. Reddish color, easily seen with naked eye on Earth, red colored rocks are found in deserts Roman god of war color of blood (second to Jupiter) Astrological symbol is a shield and spear.

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Old Mars

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  1. Old Mars Mars is further away, we see a smaller image so we need much better telescopes

  2. Mars • Reddish color, easily seen with naked eye • on Earth, red colored rocks are found in deserts • Roman god of war color of blood (second to Jupiter) • Astrological symbol is a shield and spear

  3. Until photography, all images drawn or painted • very difficult to compare observations - intervention of the observer • first image due to Fontana (1636)

  4. Refractor telescopes • Simple refractor • not a sharp image • colors have a • different focus

  5. First accurate drawing - Huygens 1659 • first showing of polar caps Huygens 1672 • Mars was seem to have dark and light areas • Dark – water (oceans, seas, bays lakes) • Bright – continents (reddish color)

  6. Syrtis Major

  7. 1672

  8. Herschel 1777-1784 • observed tilt to be ~30 degrees (like Earth) • therefore, 4 seasons (like Earth) • concluded that the inhabitants would enjoy a life similar to that on Earth

  9. Big improvement • Invention of the achromatic objective lens • Chester Hall, 1729 • Two different kinds of glass in the objective

  10. Problems with glass • 1799 • Swiss, Pierre Louis Guinand • cast high quality lenses as large as 6” • worked with Joseph von Fraunhofer, a German optician who did the grinding and polishing • later lenses were much larger

  11. Applications of new telescopes • Heinrick Mädler - school teacher (seminary), amateur astronomer • met Wilhelm Beer - banker and amateur astronomer • looked at Mars (map in 1830) • did not name features • mapped Moon 1834-1836

  12. More observations • Mountains of Mitchell, 1845 (B & M) • use of the term canale; Angel Secchi, 1858 (referred to a channel) • Dawes, 1860s, names features • also determines relation between size of telescope and resolution • begins a race for big telescopes • No standard nomenclature

  13. Next opposition • 1877 • new telescope (Alvan Clark) 26” at US Naval Observatory • new observer; Asaph Hall • not a professional astronomer • observed two satellites; Phobos (fear) and Deimos (flight) - reference to Iliad • only terrestrial planet (except Earth) with satellites

  14. At the same opposition • Giovanni Schiaparelli • accurate measurements of lat. & long. of features • introduced a nomenclature that stuck (1877) • showed long, straight, narrow dark makings • called them canali, again meaning channels • got translated into canals,artificial

  15. New features • Schiaparelli - observed gemination, a splitting of canals • canals had to be several miles wide to be seen • must have been vegetation on the banks of the canals • showed dark areas where canals crossed

  16. Names • Light areas - terrestrial or imaginary lands • Arabia, Hellas, Syria, Amazonis • dark areas - bodies of water • seas - Tyrrhenum mare • bays - Sabaeus sinus • gulfs - Golfo sabeo • lakes - Solis lacus

  17. Problems in viewing Mars • Opposition every 2 years and 50 days • best oppositions every 15 or 17 years • difficult image at opposition • next (great) opposition: August 28, 2003 • Best in thousands of years!

  18. New player • Percival Lowell 1855-1916 • an amateur but a serious one • was convinced that the canals were artificial • constructed to irrigate deserts (red color) • view of Mars as a planet drying out • Dark areas were not seas but marshes • Wave of darkening (primary evidence)

  19. If there is water on Mars • Dark areas, light areas (yes) • clouds (yes) • storms (yes) • reflection of Sun on water (no) • Reflected light not polarized (no) • but suppose the dark areas are vegetation • polar caps (yes) • red color (yes)

  20. Implications of water • On Earth, water comes from volcanic activity • volcanoes indicate geologic activity • volcanoes indicate plate tectonics • moderate temp. & atmospheric pressure • as we understand it, life can form under these conditions

  21. General conclusions, 1877 • Moderate climate • water available • large desert areas • planet losing water • an ideal place for life • sentient organisms living there

  22. Requirements for life • Moderate temperatures (between 0 and 100 C) • free water • an atmosphere • does not have to be oxygen

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