The Black Asteroid was a massive body of rock left free-floating in the Special Zone. Once, it was rich in gems and mineral deposits, until all of the minerals were mined out and the asteroid was abandoned. It appeared in three Sonic stories: The Tomb, Doomsday and The Final Victory.
When the Omni-Viewer trapped Super Sonic within its workspace, it attempted to freeze the demonic hedgehog in time, but only managed to slow it down to a crawl. With Super slowly pushing his way out, Sonic and the Chaotix Crew decided to relocate the Omni-Viewer to the Black Asteroid. Though their mission was delayed by Nack the Weasel, they succeeded in placing the Omni-Viewer within the asteroid's central cavern, then used explosive charges to seal off all entry/exit points, meaning that Super Sonic would be trapped after escaping the Omni-Viewer's workspace.
However, the plan did not turn out as Sonic had hoped. When Super Sonic emerged, the Omni-Viewer - who had been severely drained trying to keep Super Sonic contained - teleported back to Planet Meridian in order to warn the Chaotix of the impending danger. Super Sonic was using all of his power to move the Black Asteroid into Meridian's orbit and then blow it up from within. The Equinox science team discovered that the explosion of the asteroid would generate an electromagnetic pulse that would span the entire planet, knocking out all electrical devices on Meridian. Once recharged, the Omni-Viewer made a teleport test jump to Mobius, where he discovered that Dr. Robotnik had invaded the Floating Island. He then returned to the Special Zone and warned Sonic and the Chaotix, who had just defeated the Sidewinder Gang. After being told of the EMP and the situation on Mobius, Sonic told the Omni-Viewer to warp the Black Asteroid to Mobius. The purpose behind this was for the EMP to knock out all of Robotnik's technology, thus bringing about the downfall of his empire. The Omni-Viewer followed Sonic's instructions and the Black Asteroid suddenly appeared and exploded above the Metropolis Zone, releasing Super Sonic (who would soon lose his power and memories after over-exerting himself) and bringing Dr. Robotnik's reign of terror to an end.
- In part one of The Tomb, Espio mentions that the Black Asteroid was once the biggest gemstone mine on Mobius. This was most likely a script error since the asteroid was in the Special Zone and there has never been any explanation as to how or why it was there.
- Coincidentally, Sega themselves would make use of a black-coloured satellite themselves in the form of the Black Comet from the game Shadow the Hedgehog. Much like the Black Asteroid, the Black Comet was destroyed by a Super-powered hedgehog, although in the game, Shadow does so to wipe out the alien race known as the Black Arms, in order to make sure that they no longer pose a threat to the galaxy. Ironically, by the time Shadow debuted in the Fleetway canon by Sonic the Comic Online, the Black Asteroid was long since destroyed.