- You may be looking for the Black Comet.
The Black Asteroid is a location that appears in the Sonic the Comic series published by Fleetway Editions. It was once the biggest gemstone mine on Mobius which somehow ended up in the Special Zone. All that's left is the ancient tunnel shafts that litter the asteroid around a central platform.
When Super Sonic was stuck in the Omni-Viewer, Chaotix placed them in the center of the Black Asteroid and used a Graviton Bomb to close off the only entrance, burying them both under thousands of tons of rubble.
Unfortunately when Super Sonic realized what was going on he had no intention of waiting. He charged himself up with energy into an electron bomb, forcing the Omni-Viewer to release him, and caused the Black Asteroid to heat up to millions of degrees. The Asteroid began to glow like a second Sun, and would soon explode, freeing Super Sonic. In addition, the scientific laboratory Equinox discovered that the explosion would cause an electromagnetic pulse, knocking out every computer system on the planet: hospitals would shut down, aeroplanes would crash, the banking system would fail. It would cause total chaos.
At the last minute before the explosion, Sonic came up with the idea of having Omni send the Black Asteroid to Mobius, where most of the computerised systems on the planet belonged to Doctor Robotnik. The pulse spread across the planet, disabling Robotnik's Badniks and leading to the end of Robotnik's dictatorship. Super Sonic was also affected by the explosion, which drained his energy and left him without his powers or memories, and thus harmless.