The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

The accident that resulted in a commercial airplane crashing into the Potomac yesterday will require air safety investigators ...

Polio, a disease that can cause lifelong paralysis, has been eliminated from the U.S. Experts fear a resurgence if lifesaving ...

Katherine Laliotis is a freelance science writer and Ph.D. candidate in astrophysics. She often covers stories at the intersection of science and society.