X-ray images of a lightning strike
Scientists in Florida have captured the first x-ray images of a lightning strike. The images suggest a lightning bolt carries all its x-ray radiation in its tip.
The scientists were working with a lightning bolt that had been artificially triggered by rockets and wires, and that sped toward the ground at one-sixth the speed of light. At that rate of speed, scientists said, the lightning bolt would require only 10 seconds to travel to our moon.
Joseph Dwyer is a lightning researcher at the Florida Institute of Technology in Melbourne. He said scientists have known for several years that lightning emits x-rays, but until now scientists didn’t have the technology to take x-ray images quickly enough to see where the radiation comes from.
Dwyer’s graduate student Meagan Schaal accomplished the feat of making the camera which would acquire the x-rays images of lightning. The camera weighs 1,500 pounds (680 kilograms) and consists of an x-ray detector housed in a box about the size and shape of a refrigerator. The box is lined with lead to shield the x-ray detector from stray radiation.
X-rays enter the box through a small hole that in turn focuses them, like an old-fashioned pinhole camera. The result? The image on this page, in which you can see x-rays on the ground end of the lightning bolt.