Somewhere in the Milky Way tonight, drifting through the darkness between the stars, there are roughly 20 planets for every sun that burns — trillions of worlds, most thought to be ejected from the solar systems where they were born and now wandering the galaxy, according to a nine-year microlensing survey
A nine-year microlensing survey has produced the most complete count yet of the small, dark, planet-mass objects that…