In alien warfare, created by the Gray aliens in Area 51 which is found on the last levels of the game in the alien base. When fired, it shoots out incredible electronic beams which electrofy and incinerate or suck up the remains. It's rage and power are unconceivable though ammo is scarce to come across. It is presumably the most powerful weapon in the entire game.
The Meson Canon is found in the levels with the Greys and has Cole quoting "These aliens talk with friendly gestures, I talk with this Cannon." It is highly suggested that the Super Theta is shot at with at least two shells of this powerful alien weapon.
Big, grey, and packing heat, this bad boy clears an entire room. The shot is a ball of meson particles, shooting out lightning. The lightning then grabs multiple foes and sucks them into the ball.