"Although it has been a major theoretical prediction in recent years, this is one of the first unambiguous pieces of observational evidence for a chaotic, cold rain feeding a supermassive black hole," said Grant Tremblay, an astronomer with Yale University and lead author on the paper.
Peering through the ALMA telescope, Tremblay and his team studied an unusually bright galaxy cluster called Abell 2597.
Each cloud contains as much material as a million Suns and is roughly the size of tens of light-years across, and were observed by the billion-light-year-long "shadows", they cast on earth.
"This very, very hot gas can quickly cool, condense, and precipitate in much the same way that warm, humid air in Earth's atmosphere can spawn rain clouds and precipitation," Tremblay said.
Additional data from the National Science Foundation's Very Long Baseline Array shows that the gas clouds observed by ALMA are only about 300 light-years from the supermassive black hole, which in astronomical terms is near tipping point of being devoured.
Despite having only detected three clouds, astronomers believe there may thousands of clouds floating around the black hole, waiting to be consumed, allowing it to grow to an even bigger size.