What was Venus like?

[Nick]

I remember about 10 years ago being told that venus was a ravishing forest, a swampland under the heavy cloud that we couldnt see.
More recently, we have discovered it is anything but, with extreme tempeatures and pressures of the likes that can crush lead.
From waht i know now they believe that Venus used to be like earth, until soaring tempeatures microwaved the planet along with the pressure.
The thing i dont understand is how the pressure on Venus could be so high? would it be atmospheric? or gravitational causes?

I dont believe that life could have exsisted on Venus, well at least in the last few million years, but its a possibility if it was like earth.

[iceman]

I think the pressure is from the incredibly dense atmosphere. I wouldn't think the gravitational forces would be too strong as the planet is smaller than earth.

I think I read that the temperatures are like 400 degrees C under those clouds.. not the ideal building blocks for life :)

When you see sci-fi movies and earth's atmosphere ends up like venus after nuclear war or something.. i guess it's possible.. If life ever existed on venus it would have to be a very long time ago.. You'd think that it's too close to the sun (and too hot) to sustain life for too long.

[Late_Cretaceous]

Venus is such a facinating place.

I have often wondered if Venus ever harbored life. Perhaps billions of years ago before conditions on the planet literally went to hell.

However, it has been suggested that at the level of the cloud tops 30 km above the ground there could be "prebiotic (http://sps.nus.edu.sg/~kwongcha/summary.htm)" conditons. According to David Grinspoon in his book "Venus Revealed" (http://www.funkyscience.net/index.html) the suns energy is being absorbed in a way that cannot be accounted for. Not only that, but the atmosphere in general are at a dis-equalibria (similar to Earth's with it's free oxygen). The conditions up there are almost earthlike temperature and pressure wise.

Conditions on the surface are so extreme, that the atmosphere there may not even be a gas. At a temperature of 460 C, and at 96 atmospheres carbon dioxide - which makes up more then 90% of the atmosphere - exists in a supercritical fluid state (http://ull.chemistry.uakron.edu/chemsep/super/) (characteristics of both gas and liquid). Many substances could literally be dissolved in those kind of conditons.

A colleague of mine does research with supercritical fluid CO2. Currently, it is used for decaffinating coffe and removing petroleum contamination from soil.

[venus]

with the extreme weather on venus it is definately a barren place...
although you could probably swim in the atmosphere if it weren't so darn hot.