A Global View
|This mosaic of radar images taken by the Magellan spacecraft shows one
hemisphere of Venus. The long belt of bright terrain called Aphrodite Terra winds along
the equatorial region. This is an area of mountainous terrain where many volcanoes occur.
Plains dominate the regions north and south of Aphrodite. A network of long ridge belts
also appears in the north. The color of this mosaic is computer generated.
Image centered at 180 degrees east longitude
NASA Image - Catalog #PIA0040
|On the Surface
The surface of Venus is dry and hot--475 °C (900 °F) day and night
throughout the year-- and the atmospheric pressure is 90 times that of Earth's. Few probes
have entered this harsh environment, and none has survived long. Only four, all Soviet
Venera spacecraft, have returned images from the surface.
| The rocks on Venus are a dull gray, but sunlight filtered by the thick atmosphere
gives them a yellow tint. This Venera 13 color photo shows plates of rock thought to be
basalt, with dark soil between some of them. The lower photo has been corrected to show
the color of the surface as it would appear under direct sunlight. This site is probably
typical of the plains on Venus.
[194k JPEG] - [81k
Venera 13 images of the surface of Venus.
Sharp elevation differences
characterize Earth's surface: the continental areas are much higher than the ocean basins.
Venus also has a broad range of elevations, but unlike Earth most of its surface lies
within a few kilometers of the mean elevation. The high terrain consists of tessera
(possibly old and highly deformed areas) and a few large volcanoes.
in its history, Venus underwent a catastrophic "runaway greenhouse" process: the
dense carbon dioxide atmosphere trapped heat from the Sun and raised the surface
temperature to 475 °C (900 °F)--hot enough to melt lead. Any water that
existed boiled away; only trace amounts remain. The upper atmosphere contains layers of
clouds and hazes, most of which consist of droplets of sulfuric acid.
Winds near the surface are only strong enough to move
sand grains and dust particles, but the upper layers of the atmosphere move very fast.
They circle the planet every four days, a pattern called superrotation. Venus also has
atmospheric circulation patterns between the equatorial and polar areas, similar to those
Courtesy of Ronald Greeley, Arizona State University
Earth-based Observations ||
Seeing Through The Clouds || Volcanism
Other Surface Features || A Global View
|| Missions To Venus || Mysteries
Venus Facts || Imagery Index
©1998 National Air and Space Museum