The B-61-12 gravity bomb, a GPS-guided behemoth that’s been in development since 2008, can penetrate three meters of earth before detonating and dial up a nuclear yield of between 0.3 kilotons and 50 kilotons of devastating power. An Air Force B-2 stealth bomber just completed the first test drop of an advanced nuclear gravity bomb, Military.com reported on June 30. The B-61-12 gravity bomb , a GPS-guided behemoth that’s been in development since 2008 , can penetrate three meters of earth before detonating and dial up a nuclear yield of between 0.3 kilotons and 50 kilotons of devastating power. – The National Interest