Venus
About the same size as Earth, Venus has a thick, poisonous atmosphere of
carbon dioxide and sulfuric acid. The immense heat and pressure at its surface
make this planet completely uninhabitable. NASA's Magellan
spacecraft used a special radar to reveal Venus's surface during four years in
orbit from 1990 to 1994. Volcanic lava flows, quake faults and other features on
the surface were seen for the first time. The planet was also explored in flybys
by Mariner 2, 5 and 10,
and by the orbiting Pioneer Venus spacecraft.
Planet Profile
Mass (kg)............................................4.87 x 10^24
Diameter (km)........................................12104
Mean density (kg/m^3) ...............................5250
Escape velocity (m/sec)..............................10400
Average distance from Sun (AU).......................0.723
Rotation period (length of day in Earth days)........243.0 (retrograde)
Revolution period (length of year in Earth days).....224.7
Obliquity (tilt of axis degrees).....................178
Orbit inclination (degrees)..........................3.39
Orbit eccentricity (deviation from circular).........0.007
Mean surface temperature (K).........................726
Visual geometric albedo (reflectivity)...............0.59
Highest point on surface.............................Maxwell Montes
(17 km above mean planetary radius)
Atmospheric components...............................96% carbon dioxide,
3% nitrogen,
0.003% water vapor
Surface materials....................................basaltic rock and
altered materials
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