The US just dropped a 21,600-pound conventional bomb in Afghanistan.

The bomb, the Massive Ordinance Air Blast, nicknamed "Mother of All Bombs" because of its acronym, is the largest nonnuclear bomb in the US's arsenal. But Russia has an even bigger one.

The so-called father of all bombs is thought to be about four times as big as the MOAB. It's a thermobaric bomb with a destruction radius of nearly 1,000 feet and a blast yield of nearly 44 tons of TNT.

Thermobaric weapons differ from conventional bombs in that they combine with atmospheric oxygen to greatly extend the blast radius.

Developed in 2007, the FOAB explodes in midair, igniting a fuel-air mixture. It is designed to vaporize targets and collapse structures, producing powerful blasts and aftershocks but without the radioactive fallout of a nuclear weapon.

Business Insider