Australia is searching the desert for a dangerous radioactive capsule smaller than a penny

A tiny radioactive capsule fell off the back of a truck in the Western Australia desert, and authorities are conducting an intensive search to find it, reports The New York Times. The capsule, which contains cesium-137, is part of a mining sensor and is described as a "small silver cylinder measuring 0.3 inches by 0.2 inches."

"An hour of exposure at about a meter away is the equivalent of having 10 X-rays, and prolonged contact can cause skin burns, acute radiation sickness and cancer," reports the Times. Western Australia's chief health officer, Dr. Andrew Robertson, said anyone who spots it should stay at least five meters away from it.

From The New York Times:

The capsule was not lost through cartoonish buffoonery, but through an almost cinematic series of events.

According to the authorities, the sensor containing the capsule was placed inside a wooden box, which was screwed onto a pallet and placed in the back of a flatbed truck.

They believe that vibrations from the truck caused the sensor to shake apart and also dislodged a mounting bolt, leaving a hole in the bottom of the box. The capsule is believed to have fallen out of the sensor, through the bolt-hole, onto the surface of the truck, and bounced off into the road.

There's a chance the capsule will remain lost, given the vastness of the area to be searched. From The Guardian:

David Gill, a chief superintendent at Dfes, told a press conference on Saturday emergency services crews were undertaking a "concerted, coordinated" search for the capsule.

"There are challenges here. It is 1,400 kilometres between the mine site … and Perth.

"There is the potential that we may not find this," he conceded. "That is possible."

The capsule's radioactive material, which emits both gamma and beta rays, has a half-life of 30 years. Close exposure could result in burns; more sustained exposure could lead acute radiation sickness and there is the long-term risk of cancer.