UC Berkeley researchers closer to answering how many black holes wander in our galaxy

That our very own Milky Way Galaxy is home to millions — even billions — of isolated black holes is an observation that scientists have always believed. But they’re extremely hard to detect; in fact, these outer space phenomena are invisible without the light of a neighboring star.

Until now, as University of California at Berkeley scientists may have identified a free-floating black hole roaming the galaxy about 2,200 to 6,200 light-years away. The international team, led by UC Berkeley associate professor Jessica Lu and graduate student Casey Lam, discovered the lone black hole using a method known as gravitational microlensing.