One of the astronauts on the shuttle Discovery has commented that the environmental damage humans have left in their wake is visible from orbit. This isn’t breaking research or a peer-reviewed journal article; it’s just one woman’s observations, albeit from a perspective that none of us is likely to ever have first hand. But it’s very upsetting.

"Sometimes you can see how there is erosion, and you can see how there is deforestation. It's very widespread in some parts of the world," [Commander] Collins said in a conversation from space with Japanese officials in Tokyo, including Prime Minister Junichiro Koizumi.

[...]

"The atmosphere almost looks like an eggshell on an egg, it's so very thin," she said. "We know that we don't have much air, we need to protect what we have."

A pair of NASA scientists told a group of space officials at a private meeting here Sunday that they have found strong evidence that life may exist today on Mars, hidden away in caves and sustained by pockets of water. --Space.com

The evidence is indirect and inconclusive. There are plenty of alaternative explanations for the methane signatures researchers are reporting. We are all ingrained with the idea that "extraordinary claims demand extraordinary proof." And yet, even the flimsiest evidence of extraterrestrial life is enough to excite the imagination of the scientific community.

Humanity, for good and for ill, has always had a curious drive to explore and discover. Whether crossing a desert, a jungle or an ocean, explorers sought to see just a little bit more than others had seen.

In our recent history, discoveries have been largely of smaller and smaller things with big implications: genes, DNA, molecules, atoms, protons, electrons and quarks. These are important but do not inspire a sense of wonder outside of a specially trained elite group of scientists.

Anyone who has ever read a science fiction novel or played a sci-fi video game has probably heard of terraforming. The word literally means "earth shaping," and is used to describe the ecological alteration of another planet to make it habitable for humans. So far the millennial time scale and prohibitive cost of terraforming have prevented science fiction from becoming science fact.

Global warming may be a scourge on Earth, but injecting greenhouse gases into the atmosphere of Mars might be just the thing to turn the barren planet into a living and breathing world that could support future human colonies, NASA researchers said.

Scientists at NASA's Ames Research Center in Mountain View, Calif., propose using fluorine-based gases, elements of which already exist on the Martian surface, to start the warming process.