Jules Verne Voyager: Image Gallery


Venus reflectivity     Images are based on Magellan orbiter data, using the MIT Altimetric and Radiometric Global Data Records (GxDR) data sets. Because Venus has a very slow rotation rate and essentially no equitorial bulge, the planetary radius also realistically shows the surface topography (from a geoid or gravitational potential point of view). Areas of "no data" are shown as black, like the south pole (circular area towards the bottom). The rotation of Venus, by the way, is retrograde.

Venus radius

The upper image shows the surface topography of the hemisphere around Artemis Chasma, the large arc-like feature at the center. Artemis Chasma itself is generally lower in elevation than the region immediately on either side of it, and is much lower than the Aphrodite Terra, the east-west trending band of highlands to the north.

The lower image shows the surface radar reflectivity of the same hemisphere. In the mid-latitudes, there is a general correlation between the highest mountains and radar reflectivity — at altitudes above ~4000 meters (~13000 ft), there is a marked increase in reflectivity. The high elevations are surprisingly bright, although recent reexamination of the Magellan data shows a drop in reflectivity above ~4700 meters (e.g. see Phys.org: Heavy metal frost? A new look at a Venusian mystery and related Phys.org: Researcher studies possibility of metal snow on Venus). ). Possible earlier explanations have been a very thin deposit of pyrite or tellurium that has condensed out of the atmosphere on the "cooler" peaks — metallic "snow" or "frost" if you will (although the deposit could be as thin as a micron). Unexplained, as far as I can tell, is the even brighter surface towards the south pole where there are no highlands or mountains.

Venus radar reflectivity


Comments, questions, problems about Jules Verne Voyager? Send mail to   Jim Riley   (rileyunavco.org)

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Jules Verne Voyager: Image Gallery last modified on Mon, 27 Oct 2014 15:03 UTC
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