11 (tie). Soviet Tests #158 and #168
On August 25 and September 19, 1962, less than a month apart, the USSR conducted nuclear tests #158 and #168. Both tests were held over the Novaya Zemlya region of Russia, an archipelago to the north of Russia near the Arctic Ocean.
No film or photographs of the tests have been released, but both tests included the use of 10-megaton atomic bombs. These blasts would have incinerated everything within 1.77 square miles of their epicenters while causing third-degree burns up to an area of 1,090 square miles.
10. Ivy Mike
On November 1, 1952, the US tested Ivy Mike over the Marshall Islands. Ivy Mike was the world's first hydrogen bomb and had a yield of 10.4 megatons, making it 700 times as strong as the first atomic bomb.
Ivy Mike's detonation was so powerful that it vaporized the Elugelab Island where it was detonated, leaving in its place a 164-foot-deep crater. The explosion's mushroom cloud traveled 30 miles into the atmosphere.
9. Castle Romeo
Romeo was the second US nuclear detonation of the Castle Series of tests, which were conducted in 1954. All of the detonations took place over Bikini Atoll. Castle Romeo was the third-most powerful test of the series and had a yield of 11 megatons.
Romeo was the first device to be tested on a barge over open water instead of on a reef, as the US was quickly running out of islands upon which it could test nuclear weapons.
The blast would have incinerated everything within 1.91 square miles.
8. Soviet Test #123
On October 23, 1961, the Soviets conducted nuclear test #123 over Novaya Zemlya. Test #123 used a 12.5 megaton nuclear bomb. A bomb of this size would incinerate everything within 2.11 square miles while causing third-degree burns in an area of 1,309 square miles.
No footage or photographs of this nuclear test have been released.
7. Castle Yankee
Castle Yankee, the second-strongest of the Castle series tests, was conducted on May 4, 1954. The bomb was 13.5 megatons. Four days later, its fallout reached Mexico City, about 7,100 miles away.
6. Castle Bravo
Castle Bravo, detonated on February 28, 1954, was the first of the Castle series of tests and the largest US nuclear blast of all time.
Bravo was anticipated as a 6-megaton explosion. Instead, the bomb produced a 15-megaton fission blast. Its mushroom cloud reached 114,000 feet into the air.
The US military's miscalculation of the test's size resulted in the irradiation of approximately 665 inhabitants of the Marshall Islands and the radiation poisoning death of a Japanese fisherman who was 80 miles away from the detonation site.
3 (tie). Soviet Tests #173, #174, and #147
From August 5 to September 27, 1962, the USSR conducted a series of nuclear tests over Novaya Zemlya. Tests #173, #174, and #147 all stand out as being the fifth-, fourth-, and third-strongest nuclear blasts in history.
All three produced blasts of about 20 megatons, or about 1,000 times as strong as the Trinity bomb. A bomb of this strength would incinerate everything within 3 square miles.
No footage or photographs of these nuclear tests have been released.
2. Soviet Test #219
On December 24, 1962, the USSR conducted Test #219 over Novaya Zemlya. The bomb had a yield of 24.2 megatons. A bomb of this strength would incinerate everything within 3.58 square miles while causing third-degree burns in an area up to 2,250 square miles.
There are no released photos or video of this explosion.
1. The Tsar Bomba
On October 30, 1961, the USSR detonated the largest nuclear weapon ever tested and created the biggest man-made explosion in history. The blast, 3,000 times as strong as the bomb used on Hiroshima, broke windows 560 miles away, according to Slate.
The flash of light from the blast was visible up to 620 miles away.
The Tsar Bomba, as the test was ultimately known, had a yield between 50 and 58 megatons, twice the size of the second-largest nuclear blast.
A bomb of this size would create a fireball 6.4 square miles large and would be able to give humans third-degree burns within 4,080 square miles of the bomb's epicenter.
The first atomic bomb
The first atomic blast was a fraction the size of the Tsar Bomba, but it was still an explosion of almost unimaginable size.
According to the NukeMap, a weapon with a 20-kiloton yield produces a fireball with a radius of 260 meters, making its total width the size of 5 football fields. It would spew deadly radiation over an area 7 miles in width, and would produce third-degree burns in an area over 12 miles in width.
If dropped over lower Manhattan, a bomb of that size would kill over 150,000 people and produce fallout stretching all the way to central Connecticut, according to the NukeMap.
The first atomic bomb was tiny by nuclear weapons standards. But its destructiveness is sill nea lry impossible to grasp.