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A thick CO 2 atmosphere with a surface pressure 92 times that of Earth’s atmosphere hides the planet’s surface from view. Facts about Venus. *. *. *. o. *. 462 C. Venus Atmospheric Missions. Mariner 10 – Fly-by in 1973 Pioneer Venus – 5 probes in 1978 Vega 1 and 2 – 2 probes in 1985 - PowerPoint PPT Presentation
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A thick CO2 atmosphere with a surface pressure 92 times that of Earth’s atmosphere hides the planet’s surface from view
Facts about Venus
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Venus Atmospheric Missions
• Mariner 10 – Fly-by in 1973• Pioneer Venus – 5 probes in 1978• Vega 1 and 2 – 2 probes in 1985• Galileo – Fly-by in 1990• Europe’s Venus Express
(orbits in April 2006)
• Messenger (fly-bys October 2006 & June 2007)
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45 km = 100 Co
Cloud Tops
The “Greenhouse Effect” on Venus
Carbon dioxide cycle on Earth keeps us from being like Venus
But this cycle would not work if there’s no liquid water!
Single-celled floating
organisms like these
foraminifera construct fragile CaCO3 shells.
When the organisms die,
their shells sink to the ocean floor
and form limestone
deposits, thus trapping CO2.
Limestone deposits in today’s oceans
Spacecraft that have studied the surface of Venus
• Mariner 2 – 1962 – First planetary mission• Pioneer Venus – 1978 - Topography and
atmospheric probes• Veneras 8 – 14, 1975 – 1982 – Landers!• Veneras 15 & 16, 1984 – Orbital radars• Magellan – 1990 – 1994 – Orbital radar images,
topography and gravity data• Europe’s Venus Express, 2006
Venera 14 Soviet Lander - 1982
Landing Sites for Venera Spacecraft
Venera 14 views of surface of Venus
The surface of Venus, imaged by the Venera
14 Lander.
Upper image:CO2 atmosphere
results in reddish color.
Lower image:CO2 removed.
The dark rock is basalt!
Composition of the surface rocks of Venus.The rocks are basalt!
Magellan being launched from Space Shuttle
Topography of Venus from the Pioneer Venus spacecraft
The “continents” on Venus are as big or bigger than those on Earth
Maxwell Montes over 12 km high!
Maat Mons ~8 km highStill active?
Sapas Mons~400 km dia.
Cleopatra CalderaOn Lakshmi Planum
Tectonic features: Fotla Corona S.E. of Aphrodite Terra
Tessera rolling plains near Maxwell Montes
Rift zones
Stuart Crater
67 km diameterAurelia crater
32 km diameter
Unusual fluid ejecta at impact craters on Venus
Wind streaks – fine particles moved by wind
Isabella crater – Ejecta so hot it flows like lava
High surface pressure may help pancake domes form
Summary of Venus