Hi Dan: Here are some additional questions:
"There are theories that claim ‘space’ or other planets as the origination of life on Earth.
These theories have no basis, other than the possibility. Even then, the life remnants that may one day be found on other worlds could still very well be from Earth. Nanodes (much smaller than microbes) live within our atmosphere, and have for many billions of years. They have been discovered in the upper reaches of the stratosphere, and theory holds that they are buoyant enough to escape Earth’s gravity, along with our bits of hydrogen. That other fossils may be found in the Solar system is possible, but they would still be a Solar species, one related to us."

So, the question is; did Earth contaminate the Solar system with life or was Earth contaminated from space. ;-)

"For such nanodes, or even microbes, to journey as such across the vastness of interstellar space would require many billions of years -- and the Universe is theorized to be only about 14 billion years old."

Depending on their speed. I suppose that travelling at 900 km/s for 14 billion years they could be some distance away by now. I wonder if they could be accelerated to the speeds that the high energy cosmic rays have?

"We shall have to wait for what the future may tell."

True, but would you be surprised if it turns out that ‘life’ is very common in the universe?

"Not at all. In fact, I very much hope it is."

Yeah me too, regardless of where it originated. J

I agree with you on the subject matter of solar wind and its density. But without numbers on the amount of radiation being added to the upper atmosphere by nuclear ‘leaks’ from reactors all over the world, it is difficult to know if the ‘polar fountain’ has increased in magnitude since the invention of nuclear power.

"I doubt it. As we have nothing that monitors this outflow on a 24/7 basis, the levels are far to low for any precise measurement to have been archived for such a study."

That is a shame; but then doubts can be placed on both sides of the issue. What if the atmosphere is ‘boiling away’ at a faster rate than suspected? Surprises have happened before in scientific circles.

"As for the environment of Mars, there is no magnetosphere to protect what little atmosphere she holds, and there is no shield against the Solar wind, meteor storms, or coronal mass ejections. It’s a radio-hot planet, one we will need to be very prepared for when we eventually go."

Do you have links to that information?
At least there is 'water' or ice on the planet, should make it easier to quench our thirst. ;-)

"Oh, that water exists is not the question. The question remains one of quantity. No probe that has ever been sent to Mars was ever designed for serious geo-study. There is not even an example of a vessel scraping the surface to reveal what might be underneath. All our knowledge of Mars is from surface imaging, and mostly in still frames."

I suppose it depends on money .

"Mars is such a fascinating place, I’m amazed we’re not already there. Geology in all its naked glory. An entire planet, exposed to the raw elements of space, an atmosphere less than 1% Earth’s density, torn by impact events that mirrored our own, but with a planet exposing the events of history to us from afar -- and here we still sit, comfortably wondering."

How was the atmospheric pressure measured on Mars? I have been under the impression that the atmospheric density is related to the quantity of a planets mass and its density. If Mars was the same size as the Earth then there would be about the same amount of atmosphere around it. Since Mars is smaller by a certain proportion; I would expect that there would be only a proportionate decrease of atmosphere, since Mars has more than that 1% of Earth’s mass, would that not make it likely that the atmosphere of Mars is also more than 1% of Earth’s.
What if the evidence would indicate the existence of intelligent life on the planet, would we be comfortable while wondering about it? :-)

Johannes