Neutronia

Neutronia was one of the Cybertronian colonies during the Golden Age. It was one of the many planets to be hit by the Rust Plague.

Fiction

The Covenant of Primus

Mercury led the Mutacons from Neutronia when the Rust Plague claimed the planet. The Covenant of Primus

Animated cartoon

Neutronia was a destroyed planet that was part of both the Autobot Commonwealth and the Quintesson Pan Galactic Co-Prosperity Sphere in the Milky Way. The Complete AllSpark Almanac

Ask Vector Prime

In Primax 489.0 Zeta, Neutronia was destroyed by a rampaging Majin Zarak. Ask Vector Prime