|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
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.
Sometime 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 on Earth.
Courtesy of Ronald Greeley, Arizona State University
|| Seeing Through The Clouds || Volcanism
Other Surface Features || A
Global View || Missions To Venus || Mysteries
Venus Facts || Imagery
©2002 National Air and Space Museum