A mysterious radio signal from a distant planet has sparked excitement among astronomers, hinting at the tantalizing possibility of extraterrestrial life.

The observations made using the European Space Agency's XMM-Newton orbiting X-ray telescope appear to show a white dwarf nearing the point of no return - called the event horizon - as it orbits ...

disc signals, dwarf signals, lower- and upper-quadrant semaphores, motor-car signals, position-light signals, searchlight signals, and smashboards. Check out "Railroad signals 101", "Train signals ...

A red dwarf star, paired with a white dwarf ... The discovery adds to an enigmatic group of stars emitting long-period signals, raising questions about their frequency in the Milky Way.