An Internet guide to the universe
A device that renders objects truly invisible may be commonplace within the next few decades.
Fifty years ago this month, the U.S.S.R. launched Sputnik 1, the world's first Earth-orbiting artificial satellite. Shocked into action, the U.S. ramped up its space program—and its science education.
Elephant populations continue to dwindle in Tanzania.
With proper safeguards, water currents can be harnessed out of sight.
Barely pulled back from the brink of extinction, California condors are still being poisoned by lead-based ammunition.
Vulnerable everywhere in the wild, lions already face regional extinction.