Scientists believe life on alien worlds may be constrained by the same factors as on our planet.

An international research team led by the University of Vienna has produced, for the first time, high-resolution global maps of invasion risk for thousands of alien plant species under current ...

On the highly unlikely but equally mind-blowing instance in which aliens really do come down to our shiny blue planet to see what's what, perhaps it might not be wise for world leaders to be the first ...