Military and Aerospace Electronics reports that the Air Force is working to outfit the B-2 stealth bomber with a "30,000-pound bunker-busting 'super bomb.'" The bomb, known as the Massive Ordnance Penetrator (MOP), is designed to destroy deeply buried and reinforced bunkers of the type North Korea and Iran have relied upon for their nuclear weapons programs.
You can read more about the MOP at globalsecurity.org, but most significant is its ability to penetrate more than 200 feet of earth and reinforced concrete. That is a significant improvement over the GBU-28, which is a 5,000-pound laser-guided bomb that was initially used to destroy Iraqi underground facilities in the first Gulf War. And while some experts have questioned how effective bunker-busters will be against hardened targets in Iran and elsewhere, John Pike told me last year that he believed the military had deliberately fostered such doubts in an attempt "to lull the mullahs into a false sense of security." He said the GBU-28 would cut through such facilities "like a hot knife through butter," which makes one wonder just what a bomb six-times heavier could do.
Goldfarb is a fine reporter and a great writer and if you have even passing interest in military affairs, he'll be required reading for you.