The celebrated Sundance Film Festival, opening Thursday in Park City, Utah, includes films starring Natalie Portman, Olivia ...

When both minerals form, they trap small amounts of radioactive uranium – which, at a known rate, will decay into lead. By ...

A University of Arizona-led team using a camera orbiting Mars has captured the closest images yet of an interstellar comet so rare that it has sparked wild speculation about its alien origins. The ...