Two monster black holes could collide in just 100 years

Astronomers have uncovered compelling evidence of two supermassive black holes spiraling toward a potentially spectacular collision at the center of galaxy Mrk 501. A previously unseen jet of particles revealed the likely presence of a second black hole, with observations suggesting the pair completes an orbit every 121 days. Depending on their masses, these cosmic giants could merge in as little as 100 years.

Two monster black holes could collide in just 100 years. The supermassive black hole at the center, whose existence was already known, partially bends the light from the jet behind it into a so-called Einstein ring. This curved jet most likely originates from a second, unobserved black hole.

The radio observations are visible as contours in the background. These enormous objects can weigh millions or even billions of times as much as the Sun, but scientists still do not fully understand how they grow to such extraordinary sizes. Pulling in (accreting) gas from their surroundings is one way they gain mass, although this process alone may be too slow to explain the largest examples.