Scientists announced Wednesdaythe first surefire evidence of a never-before-seen type of black hole in deep space.

Why it matters: Intermediate-mass black holes could be key to understanding how black holes and galaxies form.

In May 2019, scientists using the LIGO and Virgo observatories detected a signal from two black holes colliding. That collision formed a black hole thought to be about 142 times the mass of the Sun, making it the first confirmed intermediate-mass black hole.

• It is the most massive merger detected so far: The two black holes that created this intermediate-mass black hole were about 85 and 66 solar masses. The signal from their cosmic crash took about 7 billion years to travel to Earth.
• Scientists think it's possible the 85-solar-mass black hole may have actually formed after previous mergers, adding another surprise to the detection.
• "After so many gravitational-wave observations since the first detection in 2015, it’s exciting that the universe is still throwing new things at us, and this 85-solar-mass black hole is quite the curveball," Chase Kimball, one of the authors of twostudies detailing the discovery said in a statement.

The backdrop: LIGO and Virgo detect gravitational waves — the minute ripples that warp space and time after cataclysmic crashes between black holes and neutron stars.

• These types of observations add another way for astronomers to understand the universe beyond telescopes that capture light from distant stars and galaxies.

The big picture: Scientists have plenty of examples of black holes with similar masses to the Sun — which form when large stars collapse — and supermassive black holes millions of times the mass of our star at the center of galaxies.

• But this is the first time researchers have found clear evidence of a black hole in between those extremes.
• "One of the great mysteries in astrophysics is how do supermassive black holes form?" Christopher Berry, another author of the studies said in the statement.
• "Long have we searched for an intermediate-mass black hole to bridge the gap between stellar-mass and supermassive black holes. Now, we have proof that intermediate-mass black holes do exist."

Go deeper: The hunt for a new kind of black hole