Our knowledge concerning the surface of Venus comes from a limited amount of information obtained by the series of Russian Venera landers, and primarily from extensive radar imaging of the planet. The radar imaging of the planet has been performed both from Earth-based facilities and from space probes. The most extensive radar imaging was obtained from the Magellan orbiter in a 4-year period in the early 1990s. As a consequence, we now have a detailed radar picture of the surface of Venus. The adjacent animation shows the topography of the surface as determined using the Magellan synthetic aperture radar (black areas are regions not examined by Magellan). An MPEG movie (303 kB) of this animation is also available.
Much of the surface of Venus appears to be rather young. The global data set from radar imaging reveals a number of craters consistent with an average Venus surface age of 300 million to 500 million years.
There are two "continents", which are large regions several kilometers above the average elevation. These are called Istar Terra and Aphrodite Terra. They can be seen in the preceding animation as the large green, yellow, and red regions indicating higher elevation near the equator (Aphrodite Terra) and near the top (Ishtar Terra).
|Hemispheres of Venus (Ref)|
The center image (a) is centered at the North Pole. The other four images are centered around the equator of Venus at (b) 0 degrees longitude, (c) 90 degrees east longitude, (d) 180 degrees and (d) 270 degrees east longitude. The simulated hues are based on color images recorded by the Soviet Venera 13 and 14 spacecraft. (Here is a more extensive discussion of these hemispheric views.)
|A Volcano (Ref)||Apparent Lava Flows (Ref)|
In all of
these radar images you should bear in mind that bright spots correspond to
regions that reflect more radar waves than other regions. Thus, if you could
actually see these regions with your eyes the patterns of brightness and
darkness would probably not be the same as in these images. However, the basic
features would still be the same.
There are rift valleys as large as the East African Rift (the largest on Earth). The image shown below illustrates a rift valley in the West Eistla Region, near Gula Mons and Sif Mons.
|Rift valley on Venus|
The perspective in cases like this is synthesized from radar data taken from different positions in orbit.
African Rift on Earth is a consequence of tectonic motion between the African
and Eurasian plates (the Dead Sea in Israel is also a consequence of this same
plate motion). Large rift valleys on Venus appear to be a consequence of more
local tectonic activity, since the surface of Venus still appears to be a
|A Field of Craters||The Largest Crater (Ref)|
|The surface of Venus from Venera 14 (Ref)|