Developed in 2003, the GRU-43 Massive Ordnance Air Blast is nicknamed the "Mother of All Bombs," and frequently referred to as simply "MOAB." It is the largest conventional bomb in the Pentagon's inventory, which is to say, the largest non-nuclear weapon available to the United States. The MOAB is plenty explosive, but unlike nukes, there are no radioactive after-effects. The total weight of the bomb is 21,600 pounds and of that, 18,000 pounds is a mix of explosives. The blast creates a visible mushroom cloud that could easily be mistaken for a nuclear blast. The MOAB's final test was on March 11th, 2003, just nine days before the United States invaded Iraq.