Using GIS to Study Venus

During the Magellan Mission to Venus in the 1990s, the Magellan satellite visited Venus and transmitted radar images and altimetric measurements from 97 percent of the planet. These images revealed that, like Earth, Venus has had an active geologic history modifying its surface by volcanism and tectonics. However, unlike Earth, Venus does not appear to be undergoing plate tectonics. This GIS relates the stratigraphic history to the tectonic and topographic history of a region and sheds some light on what forces drive tectonics on Venus.

Extending ArcView for Mapping Planets

Because ArcView was designed for use on Earth, some modifications were necessary to enable it to display Venus data properly. Peter Girard, formerly of ESRI-Boston, developed a Projection and Spheroid extension, which contains proper spheroid definitions for every large terrestrial body in the solar system. The Projection and Spheroid extension enables longitude to be measured positive west as it is on every planet except Venus and Earth and to range from 0 to 360 degrees instead of 180 to 180 degrees.

Geologic Map of the Baltis Vallis Region of Venus

Baltis Vallis is a canal, a sinuous channel one to three kilometers wide and more than 6,800 kilometers long that might have held lava. It is the longest known channel of any kind in the solar system, and it is formed entirely in a geologic unit mapped as plains with wrinkle ridges.

Comparing stratigraphic maps to topographic data of Baltis Vallis and other canals is useful for studying the relationships between stratigraphy and topography. A comparison between a map of the canals and gridded topography data reveals that the topography of the channel now undulates.