Hiroshima blast size windows#

1.38% of the uranium fuel actually fissioned Uranium target component ferried to Tinian via C-54 aircraft of the 509th Composite Group.Target case, barrel, uranium projectile, and other main parts ferried to Tinian Island via USS Indianapolis.140 lbs target - 85 lbs and projectile - 55 lbs Fuel: Highly enriched uranium 'Oralloy'.Dropped on the Japanese city of Hiroshima on August 6, 1945, it was the first nuclear weapon used in a war. The resulting uranium mass comprised of both projectile and target becomes critical and the chain reaction begins. In this gun-type device, the critical mass is achieved when a uranium projectile which is sub-critical is fired through a gun barrel at a uranium target which is also sub-critical. For more information, see The Science Behind the Atom Bomb. The chain reaction starts when neutrons strike the heavy uranium or plutonium nucleus which splits releasing a tremendous amount of energy along with two or more neutrons which, in turn split more nuclei, and so on. This is the minimum amount of fissionable material needed to start a chain reaction. The rock exploded over Tunguska, a sparsely populated region in Siberia, and flattened an estimated 80 million trees over an area of 770 sq miles.An explosive nuclear chain reaction occurs when a sufficient quantity of nuclear fuel, such as uranium or plutonium, is brought together to form a critical mass. In 1908 the most powerful meteor blast in modern times shook the ground in Russia. Some sustained retinal burns from watching the spectacle. No one was killed but more than 1,200 people were injured, many by flying glass.

Hiroshima blast size windows#

The flash quickly gave way to a shockwave that knocked people off their feet and shattered windows in thousands of apartments. At its most intense, the fireball burned 30 times brighter than the sun. The 20m-wide meteor that detonated over Chelyabinsk lit up the morning sky on 15 February 2013. NASA is working to identify 90% of near-Earth asteroids larger than 140 metres by 2020, but the task could take another 30 years to complete. The Bering Sea event is another reminder that despite efforts to identify and track space rocks that could pose a threat to Earth, sizeable meteors can still arrive without warning. The network was set up to detect covert nuclear bomb tests. The explosion left its mark in data recorded by a network of sensors that detect infrasound, which has a frequency too low for the human ear to pick up. Peter Brown, a meteor specialist at Western University in Canada, spotted the blast independently in measurements made by global monitoring stations. Since the event came to light, meteor researchers have been asking airlines for any sightings of the fireball, which came in close to routes used by commercial carriers flying between North America and Asia. The blast released about 40% of the energy of the meteor explosion over Chelyabinsk, according to Kelly Fast, NASAвЂ™s near-Earth objects observations programme manager, who spoke at the 50th Lunar and Planetary Science conference near Houston. The space agencyвЂ™s analysis shows that the meteor, probably a few metres wide, barrelled into EarthвЂ™s atmosphere at 72,000mph and exploded at an altitude of 16 miles. Lindley Johnson, a planetary defence officer at NASA, told BBC News that blasts of this size were expected only two or three times a century. NASA received information about the blast from the US air force after military satellites detected visible and infrared light from the fireball in December. Unlike the Chelyabinsk meteor, which was captured on CCTV, mobile phones and car dashboard cameras, the December arrival from outer space went largely unnoticed at the time because it exploded in such a remote location. It was the largest air blast since another meteor hurtled into the atmosphere over Chelyabinsk, in RussiaвЂ™s south-west, six years ago, and the second largest in the past 30 years. The fireball tore across the sky off RussiaвЂ™s Kamchatka peninsula on 18 December and released energy equivalent to 173 kilotons of TNT. Photograph: APДЄ meteor explosion over the Bering Sea late last year unleashed 10 times as much energy as the atomic bomb that destroyed Hiroshima, scientists have revealed. The meteor last December exploded over a more remote location. A dashcam image of the Chelyabinsk meteor.