Power Bomb

From Wikitroid, the Metroid wiki

Power Bombs are one of Samus's greatest weapons. They are basically charged up Morph Ball Bombs which allow for destruction of enemies within a large radius. They are essentially miniature nuclear bombs. Also, in Metroid Fusion, the blast appears to cause a vacuum that can draw in ordinary X Parasites to the center of the blast. In Metroid: Zero Mission, Super Metroid, and Fusion, they are gained from Power Bomb Tanks, though in Fusion, the initial upgrade is sent by Data Room.

In Zero Mission and Super Metroid, the Power Bombs are capable of opening Yellow Doors, and in Fusion, they can destroy orange Bio-Barriers. In all three games, they are also capable of destroying Power Bomb Blocks.

In Metroid Prime and Metroid Prime 2: Echoes the Power Bombs are arguably the strongest weapon in the game. They are able to destroy Yellow Blast Shields and destroy objects made of Bendezium (in Metroid Prime) and Denzium (in Metroid Prime 2). In Metroid Prime you have to fight the Beta Drone and get through a maze of electric barriers in the Phazon Mines to acquire Power Bombs, or alternatively you can obtain a Power Bomb Expansion in Phendrana Drifts before this by sequence breaking. In Metroid Prime 2 you have to fight the Power Bomb Guardian in Dark Torvus after acquiring Spider Ball in Sanctuary Temple. Strangely, Power Bombs are not present in Metroid Prime 3: Corruption, but a similar super-powerful Morph Ball upgrade, Hyper Ball, is acquired after defeating Mogenar on Bryyo.

Morph Ball
Morph ball | Bombs | Power Bombs Spring Ball | Boost Ball | Spider Ball Hyper Ball