From Sonic Retro
The Black Asteroid is a location in Fleetway's Sonic the Comic series. It was an astral body floating in the Special Zone that was originally the largest gemstone mine on Mobius. The only things left of the mine were the ancient shafts that litter the asteroid around a central platform in the center.
While Super Sonic was trapped within the Omni-Viewer, Sonic and the Chaotix Crew transported them to the center of the Black Asteroid, and sealed the only entrance with a Graviton Bomb, burying them both under rubble.
The Chaotix had hoped for Super Sonic to be buried within the Black Asteroid for a few years, but unfortunately, he realised what was going on and had no intention on waiting. He forced the Omni-Viewer to release him by charging himself up with energy to equate to an electron bomb, causing the Black Asteroid to heat up to millions of degrees and glow like a second sun, and would soon explode, freeing Super Sonic. Vector and the scientists from the laboratory Equinox discovered that the explosion would set off an electromagnetic pulse that would knock out every computer system on Planet Meridian and cause total chaos.
Sonic then came up with the idea for the Omni-Viewer to transport the Black Asteroid to Mobius as most of the planet's computers belonged to Dr. Robotnik. After doing so, the Black Asteroid was inevitably destroyed, and the resulting electromagnetic pulse deactivated every Badnik and computer system on the planet, essentially overthrowing Robotnik from his position of ruler. The explosion also affected Super Sonic - his energy was drained, stripping him of his powers and memories, thus rendering him harmless.