Including everything from mad scientists to robotic villains, awe-inspiring heroes, and even iconic movie monsters, these are ...

During pregnancy, maternal and fetal cells migrate back and forth across the placenta, with fetal cells entering the mother's bloodstream and tissues ...

Treponema pallidum, a microorganism that can cause a deadly sexually transmitted disease in humans, may have a far more ancient lineage than scientists once thought ...

An ancient DNA analysis of a 5,500-year-old human skeleton reveals that an ancestor of the bacterium that causes syphilis was ...

Using NASA's Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has discovered a new extrasolar planet orbiting a sun-like star. The newfound alien world, designated ...

When we imagine alien life, we picture monsters, insects, or tentacles—but what if the most realistic aliens are human-like?