More on Runaway Greenhouse Effect
"Venus lost all of its earthlike qualities. The planet has undergone a runaway greenhouse effect, losing whatever surface water it may have had to space. In the process of losing its water, Venus evolved a thick and noxious atmosphere that crushes the surface under gas pressure ninety times greater than that on Earth. Furthermore, the planet itself is intensely volcanic, and there is enough heat flow from its deep interior to melt the crust to slag occasionally."
- Peter Ward, " Life As We Do Not Know It"
More on Voyager 2
" On January 25, 1986, Voyager 2 entered the Uranus system and reported a procession of wonders. The encounter lasted only a few hours, but the data faithfully relayed back to earth have revolutionized our knowledge of the aquamarine planet, its 15 moons, its pitch black rings, and its belt of trapped high-energy charged particles. On August 25, 1989, Voyager 2 swept through the Neptune system and observed, dimly illuminated by the distant Sun, kaleidoscopic cloud patterns and a bizarre moon on which plumes of fine organic particles were being blown about by the astonishingly thin air. And in 1992, having flown beyond the outermost known planet, both Voyagers picked up radio emission though to emanate from the still remote heliopause ----- the place where the wind from the Sun gives way to wind from the stars."
-Excerpt from Carl Sagan's "Pale Blue Dot"
More on Viking 1
" For Viking 1, the original landing site seemed, after we examined orbiter photographs and late-breaking earth-based raDar data, unacceptably risky. For a while I worried that Viking 1 had been condemned, like the legendary Flying Dutchman, to wander the skies of Mars forever, never to find safe haven. Eventually, we found a suitable spot, still in Chryse but far from the confluence of the four ancient channels. The delay prevented us from setting down on July 4, 1976, but it was generally agreed that a crash landing on that date would have been an unsatisfactory two hundredth birthday present for the United States. We deboosted from orbit and entered the Martian atmosphere sixteen days later."
- Excerpt from "Cosmos"
More on Mars
"I remember being transfixed by the first lander image to show the horizon of Mars. This was not an alien world, I thought. I knew places like it in Colorado and Arizona and Nevada. There were rocks and sand drifts and a distant eminence, as natural and unselfconscious as any landscape on Earth. Mars was a place. I would, of course, have been surprised to see a grizzled prospector emerge from behind a dune leading his mule, but at the same time the idea seemed appropriate. Nothing remotely like it ever entered my mind in all the hours I spent examining the Venera 9 and 10 images of the Venus surface. One way or another, I knew, this was a world to which we would return."
- Excerpt from "Cosmos"