Primordial Black Hole Flybys Could Alter Exoplanet Orbits

Close encounters with massive objects can alter the orbits of planets around their stars. Stellar flybys can change planetary orbits, and may be responsible for some of the rogue or free-floating planets astronomers have discovered. But stars aren't the only massive objects out there, and new research suggests that primordial black holes may alter the orbits of exoplanets.