An Amazing Missions to Venus: Probing The Inferno of The Hothouse Planet

An Amazing Missions to Venus: Probing the Inferno of the Hothouse Planet

By Mr Ghaz, May 8, 2010

Image Credit

An Amazing Missions to Venus: Probing the Inferno of the Hothouse Planet

Image Credit

Venus is our nearest neighbor in space, and the planet closest in size to our own. But there the comparisons end. The Venus revealed by recent space probes in many ways resembles a medieval vision of hell. Its surface is roasted at temperatures of more than 900F, the atmospheric pressure is more than 90 times greater than that of Earth, and the “air” is thick smog of carbon dioxide and sulfuric acid.

Image Credit

A great deal of what is known about this most inhospitable of planets comes from the Venera spacecraft program of the Russian, started in the 1960’s. In addition, the United States has surveyed the planet with Pioneer probes and with other unmanned vehicles.

Image Credit

Image Credit

The first Venera probes did not survive the journey through the Venusians atmosphere to the surface, although in 1967b Venera 4 transmitted data for 94 minutes before burning up during its descent. In 1970 Venera 7 landed on the surface and broadcast for 23 minutes before being destroyed, and in 1982 Venera 13 landed and transmitted for 127 minutes. The data sent back included two color photographs of the flat, desolate terrain.

Image Credit

Image Credit

Two American Pioneer craft arrived at Venus In 1978. One was an orbiter that sent back radar observations of the surface of the planet and measurements of its upper atmosphere.

Image Credit

The second Pioneer was a “multiprobe,” consisting of a “bus” with four smaller probes that transmitted data while falling through the atmosphere. One probe survived the impact of landing to transmit from the surface for 67 minutes.

Image Credit

These achievements may seem modest compared with those of the ns missions to the moon and to Mars. Yet building instruments to withstand the extreme conditions on and around Venus represents a remarkable feat of engineering, and one that has yielded some fascinating results.

Mapping Venus

Image Credit

The radar mapping of Venus by the orbiting Pioneer revealed surface details of areas as small as 60 miles. Because of the extreme temperatures, there is no surface water on Venus. The planet is very smooth, much of it covered by a flat rolling plain; only about 10 percent of the area consists of highlands. The largest upland region is Ishtar Terra, about the same size as Australia. At Ishtar’s eastern end are the Maxwell Montes, the highest mountains on Venus; they rise some seven miles above the surface, higher than Mount Everest.

Image Credit

But scientists are most interested in two other highland areas – Beta Regio and the Scorpion’s Tail-which they suspect may contain active volcanoes. A sudden fiftyfold increase in the amount of sulfur dioxide in the atmosphere detected in 1978 is thought to have been the result of a massive volcanic eruption some 20 times more powerful than that of Mount St. Helens in 1980.

Image Credit

Much remains to be learned about what lies beneath the clouds of Venus, but conditions there make it extraordinary difficult to uncover new information. However, in 1985 the Russian adopted new tactics in its exploration of the planet.

Image Credit

Venus rotates on its axis very slowly; a Venusians day lasts 243 Earth days. But its atmosphere moves very quickly, as winds of up 250 miles per hour circle the planet in just four Earth days.

Image Credit

The Russian made good use of these winds. As the spacecraft Vega 1 and Vega 2 flew past Venus, balloons were dropped from the craft. For 46 hours they floated 33 miles above the surface of Venus.

Conditions are more tolerable at this height: the atmospheric pressure is about half that of Earth’s at sea level, and the temperature is a comfortable 90F, although the balloons still had to withstand the corrosive sulfuric acid of the planet’s clouds.

Image Credit

The missions were successful. For the present it seems that floating experiments above the hellish surface conditions is probably the best strategy for getting a long look at Venus.