Comet Enthusiast

Venus doesn't score very highly when we think of life-capable planets - with surface pressures twenty times those of Earth and temperatures which can melt tin and vaporise mercury, it's not a a good place for organics.  In fact, it's not a good place for Terminators.  But go up far enough and you find clouds with Earth-like temperatures, pressures, even chemistry (at least as far as original ingredients go).  The fact that Venus boiled off all its oceans and turned them into sulfuric acid doesn't cancel out the fact there's water and heat aplenty.

In fact, the sulphur might help.  High above the Venusian surface the atmosphere is bathed in ultraviolet radiation, aka "That stuff that burns big things and kills small ones", but Professor Ingersoll (of the Californian Institute of Technology) and colleagues believe that extraplanetary microbes could learn to use these chemicals as a sunscreen - if they haven't adapted to UV altogether.

We've already seen Earth-borne bacteria surviving high in the clouds or in acidic environments, and the fact we haven't seen both at the same time is only because Earth doesn't have places like that.  Some suggest that Venus's conversion from an early Earth-a-like to a fair approximation of hell might have been slow - slow enough to allow life to occur, then evolve to adapt to a narrowing habitable zone.

Venus' lower cloud deck at an altitude of 50 kilometers has water vapor, potential nutrients, and a temperature of 30 to 70 degrees centigrade and pressure similar to Earth's surface. The theory is that microbes that might have evolved in the ancient oceans of the second planet billions of years ago when the Sun was much cooler, adapted to a purely airborne state as the oceans boiled away. The atmosphere of Venus has a chemical disequilibrium similar, although not as pronounced as Earth's demands an explanation, and a clear possibility is that biology is at work.

There's even a NASA option to fly there, deploy a floating collector, and rocket the samples back to Earth for analysis.  Not only might there be other life in the universe - they might live right next door.

Posted by Luke McKinney with Casey Kazan.

Venusian Life-forms