The surface of the second largest terrestrial planet in our solar system is also one of the least explored. Venus is a place where devils even fear to tread. Why? Imagine putting your electric oven on self-clean mode and then placing your iPod on one of the racks inside. How long would the iPod play until it became a blob of molten aluminum and plastic?
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Now imagine building a sophisticated computer-electronics device that could take this kind of roasting for a few hours. That's what you'd have to do if you wanted to send a robotic prospector to Venus' surface.
Just a few Soviet probes have ever made it down to Venus’ surface, though numerous landers and rovers have visited various locations on Mars.
The first Venus landing was accomplished 40 years ago when the Soviet Venera 7 made a hard touchdown (enough to tip over the vehicle) on basaltic rock. The probe’s batteries lasted only 25 minutes, just long enough to send back just a few pictures of a bleak, eroded landscape.
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We have a lot of unanswered questions about Venus that warrant a return surface visit. Venus might have once had oceans and even incubated life. But the oceans quickly evaporated into space. Recent data from the European Space Agency’s Venus Express orbiter shows hydrogen leaking into space, which would come from ultraviolet light breaking apart water molecules.
There is circumstantial evidence that the highland plateaus of Venus -- as radar and infrared-mapped by orbiters -- are ancient continents that sat on top of the denser basaltic seabeds.
Compelling evidence would be provided if a lander found granite, which on Earth was is formed by the action of seawater with molten lava under tremendous pressures.
If there were Venusian oceans, and their evaporation was slow enough for life to begin and adapt, microbes might have fled into the thick atmosphere. The environment is balmy a few dozen miles above the surface where temperatures are 150 degree Fahrenheit and there is a concentration of water vapor.
To further explore these questions, NASA is considering a mission to land the first U.S. probe on Venus. It is called the Surface and Atmosphere Geochemical Explorer (SAGE). The Venus visit is not funded, but competing for space bucks with other solar system missions under study.
Unlike a treacherous Mars landing -- that requires a complex choreography between supersonic parachutes and retro-rockets -- the descent to Venus’ surface would be a relative cakewalk. Parachutes would deploy in the thick atmosphere to facilitate a gentle landing at the end of a leisurely hour-long drop.
The Venusian atmosphere is cloudless below about 50 miles altitude. A descent camera on the probe would snap off pictures, just as the European Space Agency did with their Huygens lander on Titan in 2005. The aerial view of a primeval lava glazed surface would be unlike anything seen elsewhere in the solar system.
The SAGE probe design resembles – appropriately enough -- a Weber charcoal grill. It would land near the edge of Mielikki Mons, a 4,500 foot-high volcano.
The lander would operate for for just a few hours before succumbing to the 850-degree Fahrenheit Venus kiln. Therefore, multiple instruments running simultaneously would play a game of “beat the clock” and furiously collect weather and mineralogical data while snapping off tourist pictures. They would have merely a one-hour window to suck up data before transmitting it back to Earth.
The probe would measure the composition of the surface and even dig a few inches into the ground. The surface would be zapped with two lasers and a neutron beam for chemical analysis. A mass spectrometer would sniff-out atmospheric gasses.
Before we speculate about conditions on terrestrial planets being discovered around other stars, it behooves us to get to know why Venus underwent such a different evolution from Earth. The planet is nearly the same size as Earth, and has similar composition. But, clearly, it has a tortured history that is not well understood.
Tags: Venus
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