Water boils at 212 degrees Fahrenheit. What happens to it at 99,000 degrees?. That was the temperature of the water in the Marshall Islands in the Pacific Ocean after the United States tested a thermonuclear device there in 1954.

The expected yield was to be in the neighborhood of four to six megatons. In the event, the bomb was significantly more powerful: fifteen megatons. Forty-two species of coral never recovered from boiling at temperatures so high. Indeed, they were vaporized along with much of Bikini Atoll, the test site.

But National Geographic reports that an amazing recovery is under way:

It was awesome to see coral cover as high as 80 percent and large treelike branching formations with trunks 30 centimeters (11 inches) thick,” Zoe Richards of the ARC Centre of Excellence for Coral Reef Studies said in a statement.

Nonetheless, anyone who watches a video of the blast itself, available here, will understand that even if coral recovers nicely after half a century, it would be wise to keep these weapons out of the hands of Iranian ayatollahs.