- The "mother of all bombs" dropped by the US military is not the most powerful conventional bomb.
- The "father of all bombs," built by Russia, explodes with four times more energy.
- FOABs are designed to break up and incinerate their targets like nuclear weapons, but without the radioactive fallout.
On April 13, the US military dropped a school bus-size munition nicknamed the "mother of all bombs" on a network of ISIS-held caves and bunkers in northeastern Afghanistan, according to the Pentagon.
Weighing about 21,600 pounds and stretching 30 feet, each MOAB (officially called the GBU-43/B Massive Ordnance Air Blast) can explode with the power of about 11 tons' worth of TNT, making it the largest conventional bomb in the US arsenal.
However, MOABs are not the most powerful non-nuclear explosives in the world.
That title belongs to the Russian-built "father of all bombs," also called "Blackjack" by NATO.
Each FOAB can detonate with the power of 44 tons' worth of TNT, or with four times the MOAB's yield. (This is more than 1,000 times weaker than the first atomic bomb detonations.)
But these gigantic bombs are two entirely different beasts designed to kill enemies in different situations.
MOABs, as Business Insider's Rafi Letzter explained, blow up about six feet above a subterranean target. By not hitting the ground, the bomb avoids wasting energy to form a crater; instead, the energy goes into a powerful shockwave.
That shockwave reflects off the ground, recombines with itself at the edges, and forms a doubly powerful "mach stem," which can penetrate deep into the ground, blast through buried structures (like a bunker), and collapse them.
Here's an infrared view of the April 13, 2017, attack on ISIS:
Where MOABs mainly try to crush a target, however, FOABs provide a giant one-two-punch of crushing and incinerating.
How the 'father of all bombs' works
Unlike the MOAB, the FOAB is a thermobaric weapon, meaning the primary goal is to burn up a target — so it forms a humongous fireball.
FOABs accomplish such fiery devastation by surrounding a core of high explosives (which a MOAB is almost entirely made out of) with many tons of fuel.
High explosives don't really burn. Instead, they expand very rapidly and generate powerful shockwaves in the process. They're the same materials that surround the core of a nuclear bomb and cause it to implode.
Upon detonation in a FOAB, the high explosives rapidly spread out the fuel, helping it burn up as quickly as possible. The explosion can deliver an otherworldy surge of heat to anything within about 1,000 feet and gobbles up most of the oxygen in the blast zone.
As Jeremy Bender explained in a 2015 Business Insider post: "Everything within that area becomes super-heated to the point that surfaces melt, and the ground takes on an almost moon-like quality."
Shortly after the 2007 test of a FOAB, Alexander Rukshin, then the deputy chief of the Russian armed forces, told Russia's ORT First Channel: "The main destruction is inflicted by an ultrasonic shock wave and an incredibly high temperature. All that is alive merely evaporates."
The goal, Rukshin noted, is to achieve the incendiary damage of a nuclear weapon — but without the horrors of long-lived radioactive fallout sprinkling for miles beyond a target.
The historical effects of burning bombs
The effects of fiery bomb attacks are, unfortunately, rife in the history of modern warfare, and in particular World War II.
The night of February 13, 1945, for example, allied forces bombed Dresden, Germany, with hundreds of tons of bombs. Most of the bombs were packed with high-explosives to destroy structures, like a MOAB, but some were designed to burn targets, like a FOAB.
The amount of buildings set ablaze led to a firestorm, which created such intense heat that it scorched everything and everyone — including women and children — for miles around.
The late US author Kurt Vonnegut was a prisoner of war in Dresden at the time, and was hustled into a basement meat locker during the attack. When he emerged, he described the scene like this to an interviewer, according to "Making of the Atomic Bomb" by Richard Rhodes:
"Every day [afterward] we walked into the city and dug into basements and shelters to get the corpses out, as a sanitary measure. When we went into them, a typical shelter, an ordinary basement usually, looked like a streetcar full of people who'd simultaneously had heart failure. Just people sitting there in their chairs, all dead. A fire storm is an amazing thing. It doesn't occur in nature. It's fed by the tornadoes that occur in the midst of it and there isn't a damned thing to breathe."
Similarly, the US Air Force firebombed Tokyo and many other Japanese cities in 1945. Many of the bombs were packed with napalm — or jellied gasoline fuel — and designed to torch their targets, not blow them up.
The attacks also generated powerful firestorms, killed hundreds of thousands of people in the blazes, and left behind a horrifying legacy that many survivors say is largely ignored in the shadow of the first nuclear strikes on Hiroshima and Nagasaki.
This story was updated after its publication.
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