This has been a big week in Alzheimer's news as scientists put together a clearer picture than ever before of how the disease affects the brain. Three recently published studies have detected the disease with new technologies, hinted at its prevalence, and described at last how it makes its lethal progress through the brain.

A potentially habitable alien planet -- one that scientists say is the best candidate yet to harbor water, and possibly even life, on its surface -- has been found around a nearby star.

Contact lenses that help enhance normal vision with megapixel 3D panoramic images are being designed by scientists using military funding.

The color of a candidate’s skin failed to sway voters to depress the lever for either Obama or McCain in the 2008 election, immediate analyses of that contest seemed to suggest. Some pundits hailed it as the first postracial election.

At a tiny outpost in the middle of Antarctica, Russian scientists are poised to become the first humans to reach a massive liquid lake that has been cut off from the sunlit world for millennia, and may house uniquely adapted life forms that are new to science.