NASA

They say big things come in little packages. That may never be more true than with what astronomers have just discovered: A "monster" black hole hiding inside one of the smallest galaxies ever known.

NASA said Wednesday that astronomers using its Hubble Space Telescope have found a new dwarf galaxy -- known as M60-UCD1 -- that "crams 140 million stars within a diameter of about 300 light-years, which is only 1/500th" the diameter of the Milky Way galaxy.

At the core of this tiny galaxy is what NASA is calling a "supermassive," or "monster" black hole, one that has five times the mass of the black hole at the center of our own Milky Way galaxy. A dwarf galaxy is one that has a small fraction of the hundreds of billion of stars in the Milky Way.

However, when comparing the density of the Milky Way and the newly-discovered galaxy, NASA said looking at the nighttime sky from Earth reveals about 4,000 stars. Someone looking up into the sky from inside M60-UCD1 would see a million stars.

According to NASA, this finding indicates there could be many other dense galaxies throughout the universe that also have giant black holes. At the same time, the space agency said, the discovery may mean that dwarf galaxies like M60-UCD1 could be the ripped remnants of larger galaxies that broke apart during violent events such as collisions with other galaxies.

"We don't know of any other way you could make a black hole so big in an object this small," Anil Seth, the University of Utah astronomer who led a study about the newly-found galaxy, said in a NASA statement.

Seth's team used both the Hubble telescope and Hawaii's Gemini North-8 meter optical and infrared telescope to identify the new galaxy and measure the black hole's mass.

NASA explained that black holes are "gravitationally collapsed, ultra-compact objects that have a gravitational pull so strong that even light cannot escape."