The United States on April 13, 2017, dropped a massive GBU-43 bomb in eastern Afghanistan against a series of caves used by Islamic State militants. According to the Afghanistan officials, the bomb killed over 30 Islamic State militants in the area.

What is the GBU-43 bomb?

The Massive Ordnance Air Blast bomb (MOAB) also known as the ‘mother of all bombs’ is the largest non-nuclear bomb ever deployed in combat by the United States. The GBU-43 is a 21,600 pound (9,797 kg) GPS-guided munition and was first tested in March 2003, just days before the start of the Iraq war. It is a demolition bomb containing 18,700 pounds (8,480 kilogrammes) of the explosive H6, with a blast yield equivalent to 11 tonns of TNT. Nine metres (30 feet) long, with a diameter of one metre, according to GlobalSecurity.org, it is the largest-ever satellite-guided, air-delivered weapon in history.

What was the MOAB designed for?

The MOAB is a custom-made Air Force weapon that has been in the arsenal for more than a decade. It is designed to hit softer targets such as surface facilities, tunnel entrances and troop concentrations. It is a concussive bomb, meaning it is designed to detonate before it hits the ground. Its thin aluminium skin helps to maximise its blast radius and generate a shockwave, according to Wired.com.

How is the MOAB deployed?

The MOAB is dropped off from the cargo ramp of a C-130 transport plane with its descent slowed by parachute. This means it can be deployed from a greater height, thereby offering pilots more time to reach safety.

What is the Pentagon's view on the MOAB?

In the Pentagon's 2003 review of the legality of using the MOAB, it was concluded that it could not be called an indiscriminate killer under the Law of Armed Conflict.

“Although the MOAB weapon leaves a large footprint, it is discriminate and requires a deliberate launching toward the target,” the review said. It added, “It is expected that the weapon will have a substantial psychological effect on those who witness its use.”

Who made the bomb?

The MOAB was developed in 2002-2003 by Alabama-based aerospace and defence company Dynetics in partnership with the Air Force Research Lab (AFRL), according to the company's website. The website said the bomb's preliminary concept was developed into a detailed design within just three months, and successfully tested three times in 13 days. According to the Air Force, the last time the MOAB was tested in 2003, a huge mushroom cloud could be seen from 32 km away.