A Russian scientist compiled first full geological map of the Morning Star, which will help finding answers to many questions about planet’s and Solar system’s evolution and history, as well as about possible future of our own planet.

The map shows main trends in geological history. The global geological map is the part of massive Venus land surveying, which takes place in the United States. The scientist expects receiving a Russian grant for publishing atlas of Earth’s neighbouring planet. Venus is quite alike Earth – its diameter, being 12.1 thousand kilometers, is only 700 km shorter that Earth’s, and average density is 5.2 grams per cubic centimeter (compare to 5.5 grams of Earth’s average density). All these point to similar chemical composition of Venus and Earth.

However, surface of the Morning Star always hides behind a dense veil of clouds, making scientists of the past inventing various hypotheses about what happened down there. Most popular hypothesis was that clouds cover hot and humid climate, like Earth’s tropics. Writers inhabited Venus with living beings and predicted forthcoming colonization of the planet, but Soviet and American probes ruined romantic dreams.

Venus appears to have a strong greenhouse effect, which heat surface up to 500 degrees Centigrade. No life can survive in this boiling pot. Moreover, the planet acts like a giant thermostatic oven, in which equator has the same temperature as poles. Clouds made geologists work hard, since they made observing Venusian surface impossible, and scientists had to use radiolocations, placed aboard interplanetary probes. First information arrived from Amecial orbital vehicle “Pioneer-Venus”, but resolution of the images was very low – about 20 kilometers per pixel. Later Soviet space ships “Venus-15” and “Venus-16” continued radar survey of the planet’s surface, and American “Magellan” was a great help, mapping about 97% of Venus’s surface with resolution of 100-200 meters per pixel. These data are not the basis for all geological interpretations for Venus.

 

 

Main specific features of Venusian geology come from relatively large mass of the planet and absence of water and life. Being heavy means plenty of heat inside, leading to high tectonic and volcanic activity. Water and living beings are key factors for mighty erosion and sediment formation – characteristic features of Earth’s geology. “Magellan” showed that Venus’s surface is relatively young. Much younger than surfaces of Mercury, Moon and Mars. Moreover, Venus lacks any plate tectonics, which moves Earth’s continents, being the main mechanism for heat loss. The Morning Star should have another mechanism for getting rid of excessive heat, and research probes showed that volcanic activity was the most important process in Venus’s core formation. This fact simplifies geological chronicles of Venus and helps comparing distant regions of the planet.

After “Magellan”’s information arrived, United States Geological service started mapping Venus, which surface was divided into 62 parts, having been mapped by groups of geologists. Russian scientist, the author of Venusian map, is responsible for 8 parts, six of which are already published. The researcher, who thinks that so many people involved in mapping would finally result in “border faults”, started his own mapping of Venusian surface in 1:10 000 000 scale. The map in based upon a stratigraphical model, created by Russian and American scientists.

The map will help understanding how tectonic intensity, if any, changed with time, how volcanic processes developed, what dynamic change of Venusian mantle were. Answers to these questions will reveal a lot about Earth’s own past and future.

Source: RIA Novosti

Kizilova Anna