We probably won’t hear from aliens. But by the time we do, they’ll be dead.
A new Drake Equation calculation suggests ghost signals haunt parts of the Milky Way
![animation of signals from alien civilizations](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2018/03/030918_drake_equation_main.gif?fit=840%2C449&ssl=1)
CAN YOU HEAR ME NOW? Electromagnetic signals (blue circles) from alien civilizations will continue traveling through the Milky Way even after the aliens are gone. The appearance of a doughnut hole represents when a civilization dies out.
Geoff Marcy