Great Ball of Fire: X-Rays Spot Mass of Gas 5 Billion Times Larger Than Solar System

Scientists have discovered the largest ball of hot gas ever found, a monstrous sphere of fire streaking through a galaxy cluster millions of light-years away.

“The size and velocity of this gas ball is truly fantastic,” said physicist Alexis Finoguenov of the University of Maryland, Baltimore County. “This is likely a massive building block being delivered to one of the largest assembly of galaxies we know.”

The gas ball, which was found using the European XMMNewton X-ray space observatory, is 3 million light-years across -- 5 billion times the size of our solar system. Images show it as a circular X-ray glow with a stumpy comet-like tail.

The ball is moving through a galaxy cluster called Abell 3266, which contains hundreds of galaxies.

The gas ball and other gas formations are thought to be held together by unseen dark matter that many scientists think makes up as much as 90% of the universe.

Abell 3266 is part of the Horologium-Reticulum supercluster, one of the most massive accumulations of galaxies in the southern sky. It continues to grow, and the newly discovered gas ball feeds that growth.

The researchers, who announced the discovery Tuesday, estimate that material equal to the mass of our sun is being stripped away every hour.

Mark Henriksen, a physics professor at the Baltimore County campus and the coauthor of a paper describing the findings in the June issue of the Astrophysical Journal, said that as the gas ball races through the cluster, individual galaxies tear portions of it away to seed future star growth.

Henriksen contrasted the gas ball with a giant comet streaking through the heavens: A comet is made of ice and dust, but the gas ball’s temperature is 100 million degrees -- so hot it is invisible in optical light.