(NEXSTAR) — A supermassive black hole is speeding across the galaxy, and astronomers are baffled as to why.

The fast-moving black hole, which is about 3 million times heavier than the sun, is traveling at 110,000 mph about 230 million light-years from Earth, according to researchers at the Center for Astrophysics, Harvard and Smithsonian.

“We don’t expect the majority of supermassive black holes to be moving; they’re usually content to just sit around,” Dominic Pesce, an astronomer at the Center for Astrophysics who led the study, said in a statement. “They’re just so heavy that it’s tough to get them going. “

Scientists have long thought black holes could move, but such movement is rare because their immense size needs an equally substantial force to get them in motion.  

“Consider how much more difficult it is to kick a bowling ball into motion than it is to kick a soccer ball — realizing that in this case, the ‘bowling ball’ is several million times the mass of our Sun,” Pesce said. “That’s going to require a pretty mighty kick.”

Pesce and a team of researchers have been working for five years to observe this rarity by comparing the velocities of supermassive black holes and galaxies. They initially studied 10 distant galaxies and the supermassive black holes at their cores. They focused on black holes with water in their accretion disks, which are spirals that spin inward towards the black hole.

Pesce said as the water orbits the black hole, a laser-like beam of radio light is produced. When analyzed with a combined network of radio antennas, the light beam — known as a maser — can help measure a black hole’s velocity.

The researchers found that only one of the 10 black holes seemed to be moving — one that sits at the center of a galaxy called J0437+2456. But the reason for its movement is unclear.

Researchers suspect two possibilities.

One is the aftermath of two black holes merging, causing “the newborn black hole to recoil,” said Jim Condon, a radio astronomer at the National Radio Astronomy Observatory who participated in the study.

The other possibility is that the black hole is part of a binary system.

“Despite every expectation that they really ought to be out there in some abundance, scientists have had a hard time identifying clear examples of binary supermassive black holes,” Pesce says. “What we could be seeing in the galaxy J0437+2456 is one of the black holes in such a pair, with the other remaining hidden to our radio observations because of its lack of maser emission.”

Researchers said more study is needed to find a definitive cause for the black hole’s rare movement.