There are an estimated 100 million black holes strewn throughout the Milky Way galaxy. Each one that astronomers have identified are part of a larger neighborhood of stars and other objects that share in some kind of gravitational tug-and-pull. But scientists believe that, just by sheer odds, there must be some black holes that are rogue wanderers, floating aimlessly through interstellar space without any companions around.
It seems astronomers might have finally found one. NASA’s Hubble Space Telescope has detected evidence of a lone black hole drifting around space, 5,000 light-years away. And furthermore, its discovery suggests that the nearest rogue black hole to Earth might be as close as 80 light-years away.
The researchers behind the new discovery, which was announced in two papers that have been accepted for publication by The Astrophysical Journal, caution the new object isn’t a verified black hole yet; it may simply be another kind of massive object like a neutron star. Should the findings stand up to muster, though, this phantom black hole would be unlike anything astronomers have ever seen before.
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The two papers are notable for using the same stack of data collected by Hubble, as well as ground-based instruments located in Chile and New Zealand. Both found the new object through a technique called microlensing, which observes how the movement, brightness, and curvature of light traveling through space changes due to the gravitational force of other objects.
The papers differ slightly in their estimations of how far away the new object is. They also have different conclusions on how fast the object is traveling—one estimation is 30 kilometers per second, while the other is 45 km/s.
A little more analysis is needed to confirm the new object is a black hole, but regardless, the findings point the way to finding other rogue black holes and mysterious objects drifting around quietly through the vast emptiness of space.
