Alt-week takes a look at the best science and alternative tech stories from the last seven days.

Altweek 61513 Chris Hadfield retires, invisibility cloaks and energyscavenging micro devices

What goes up must eventually come down, and shortly after landing on Terra Firma from his last of three ISS missions, Chris Hadfield has resigned from the Canadian Space Agency. That leaves us to wax poetic on his legacy of space education and other oddities, while we also make goldfish disappear and admire dinosaur plumage. Welcome to alt-week.

Space exploration is serious business, but you wouldn't know it by watching charismatic Canadian astronaut Chris Hadfield, who just finished a stint commanding the International Space Station for 144 days. While getting that job done, Hadfield also flaunted breathtaking earthscape images, educated us on the weirdness of the zero-g environment, and even entertained with a surprisingly decent version of Bowie's "Space Oddity" from actual space -- prompting a "Hallo, spaceboy" reply from Ziggy Stardust himself. Shortly after rejoining the earthbound (see the video, above), Hadfield announced his retirement from the Canadian Space Agency and said he'd be moving back to his home in Ontario. Of course, he'll continue inspiring interest in science at Canadian schools while waving the space exploration flag on behalf of the CSA, and as his wife, Helene, said, "anything Chris does is always an adventure."

To date, so-called invisibility shields have been more or less parlor tricks, where the scene behind an object is projected onto the front, camouflaging it from the environment. However, such razzle-dazzle only works when viewed head on, making it useless in any practical applications. But researchers from Zhejiang University in China have created a pair of invisibility shields, one that cloaked a cat from any of four different directions, and another hexagonal system that shielded a goldfish from six viewing angles. Any object in the interior of the shields can be cached, thanks to optical systems that map the correct background to the given view. Though the illusion breaks down if you change the viewing angle, such a device would be cheap and easy to build, according to scientists -- meaning you may soon be able to put that pet-hiding project on the front burner.

Altweek 61513 Chris Hadfield retires, invisibility cloaks and dinobirds

Recently, we've had our childhood delusions dashed by the discovery that our favorite dinosaurs likely had feathers. But what about the plumage of actual, soaring dino-birds like Archaeopteryx? Little was known about its color and composition due to the breakdown and fossilization of the organic elements over hundreds of millions of years. Thanks to research at the Department of Energy's (DOE) SLAC National Accelerator Laboratory, though, scientists now have a complete picture of that species' feathers, right down to the coloration -- which was light overall and dark at the tips, not uniformly dark as previously thought. All that was possible thanks to SLAC's ultra-sensitive X-ray beams, which discovered traces of pigment-related metals and organic sulfur compounds that could only have come from the extinct dino-birds themselves. The results go beyond the feathers, giving clues into the animal's health, diet and even mating rituals -- which we certainly wouldn't want to get in the middle of, judging by the image above. Check the video below for more.