The U.S. on Thursday dropped the most powerful conventional bomb in its arsenal on Nangarhar, Afghanistan.

The bomb, known in military ranks as “MOAB,” or the “mother of all bombs,” was used Thursday for the first time in combat, though it was developed in the early 2000s.

U.S. Army Gen. John Nicholson, commander of U.S. forces in Afghanistan, ordered the bomb dropped, according to reports. The target was believed to be ISIS tunnels and personnel in the Achin district of Nangarhar.

"This is the right munition to reduce these obstacles and maintain the momentum of our offensive against ISIS-K," he added, using the U.S. military's acronym for the IS affiliate.

According to The Associated Press, the U.S. military headquarters in Kabul said in a statement that the bomb was dropped at 7:32 p.m. local time Thursday.

Here’s what we know about the MOAB.

What is its name?

The bomb’s technical name is GBU-43/B Massive Ordnance Air Blast (MOAB) bomb. It became known in military circles as the “mother of all bombs” because of its size and power.

Who makes the bomb?

It was designed by the Air Force Research Laboratory and is manufactured by McAlester Army Ammunition Plant in Oklahoma.

How big is it?

The MOAB is 30 feet long and has a 40.5-inch diameter. The bomb weighs 21,715 pounds. The warhead weighs 18,739 pounds.

How is it dropped?

It is delivered by a C-130 Hercules military transport plane. It's basically pushed out of the back of the massive plane. It is attached to a parachute.

What kind of blast does it produce?

The “blast yield” of MOAB equals 11 tons. It has a blast radius of 1 mile, meaning that it demolishes everything within 1 square mile.

When was it developed?

The GBU-43/B Massive Ordnance Air Blast was developed in 2003. The bomb was developed in only nine weeks to be available for use in the Iraqi War.

It has been tested only twice, both times at Eglin Air Force Base in the Florida Panhandle.

FILE PHOTO -  In this U.S. Air Force handout, a GBU-43/B bomb, or Massive Ordnance Air Blast (MOAB) bomb, is launched November 21, 2003 at Eglin Air Force Base, Florida. MOAB is a 21,700-pound that was dropped from a plane at 20, 000 feet. A bomb similar to this one was dropped in Afghanistan Thursday.

Credit: USAF via Getty Images

icon to expand image

Credit: USAF via Getty Images

How many are in existence?

According to the Air Force, 15 units were made at the McAlester Army Ammunition Plant. One of those was moved to the Persian Gulf in 2003.

When have they been used in combat?

The first and only time that one has been used in combat was on Thursday in Afghanistan.

A Massive Ordnance Air Blast- or more commonly known as the Mother of All Bombs -(MOAB) weapon is prepared for testing at the Eglin Air Force Armament Center on March 11, 2003. The MOAB is a precision-guided munition weighing 21,500 pounds and will be dropped from a C-130 Hercules aircraft for the test. It will be the largest non-nuclear conventional weapon in existence. The MOAB is an Air Force Research Laboratory technology project that began in fiscal year 2002 and was scheduled to be completed in 2003.

Credit: wikipedia

icon to expand image

Credit: wikipedia

Does it penetrate the ground to blow up tunnels?

No. It is an “air-blast” bomb, meaning that the bomb explodes in the air and the blast from the weapon does the damage.

Is the U.S. the only country with the MOAB?

Yes. There have been reports that Russia developed a “father of all bombs” after news of the MOAB broke. It is said to be four times more powerful than the MOAB.