The Eclipse Cannon (エクリプスキャノン, Ekuripusu Kyanon) is the ultimate weapon of mass destruction on the Space Colony ARK created by Professor Gerald Robotnik, able to destroy planets and pierce stars. The Chaos Emeralds are needed to power the cannon, as it takes large amounts of energy to power it. The Cannon can be seen on the outside of the ARK as it forms the "nose" of the research center.
Despite its frightning power, the intended purpose of the Eclipe Cannon was to destroy the Black Comet in order to save the Earth from being overrun by the evil alien forces residing there. Around fifty years later, in the Shadow Saga, the Eclipse Cannon was used by Dr. Eggman in an attempt to assume control over the world by threatening to fire it at the planet, but the Eclipse Cannon was stopped due to efforts of Ash Ketchum, Sonic the Hedgehog and their friends, and the late Gerald Robotnik's doomsday program. In the Black Arms Saga, the Eclipse Cannon finally carried out its purpose when Shadow the Hedgehog used it to destroy the Black Comet.
Using only five Emeralds, it is capable of destroying a large city and produce a large crater in a planet; with six Emeralds, it is able to destroy half of a moon. However, with either case, the cannon would require twenty-four hours to recharge due to the large energy consumption.