Explorations of the Universe

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Explorations of the Universe

• Mars

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Mars

• About half the size of Earth
• Rotates in 24.5 hours
• Ranges from 207 to 249 million km (129 to 155
  million miles) from Sun
• Period 687 days
• Two tiny satellites

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The Surface of Mars

• Thin carbon dioxide atmosphere about 1/150 as
  dense as Earths
• Surface temperatures -20 to -200 C
• Polar caps of ice and frozen carbon dioxide
• Large rift valley (Vallis Marineris)
• Huge Shield Volcanoes (Olympus Mons)
• Evidence for former liquid water

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Mars as Lowell Knew It
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Modern Imaging Technology Improves Earth-Based
Views of Mars Greatly
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Mars from Mariner 9
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Mars Viking Mosaic
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Vallis Marineris
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Huge Landslide in Vallis Marineris
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Layered Deposits in Vallis Marineris
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Olympus Mons
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Summit of Olympus Mons
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Phobos over Olympus Mons
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The Polar Caps
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Water on Mars
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Channels on Mars
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Floods on Mars
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Wheres the Water Now?
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How to Lose an Ocean

• If water is exposed to solar UV and particles, it
  breaks down to H O (photo-dissociation)
• Happens if water gets into upper atmosphere
• Planet gets hot (Venus)
• Planet loses atmosphere (Mars)
• Oxygen combines with iron and other elements, on
  Mars may also have escaped

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Mars as Seen by Viking
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Mars from Pathfinder
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Martian Winter
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Phobos and Deimos
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The Face on Mars
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