The study's authors emphasized that the overall likelihood of getting the cancers remained very small and that the immediate benefits of the scans, such as in detecting head injuries, still outweigh the risks.

WSJ: Childhood CT Scans Pose Cancer Risk

"If there is a supernova in our vicinity during the next couple of months, our chances of detecting and measuring the resulting gravitational waves are good, " said Professor Karsten Danzmann, head of the International Centre for Gravitational Physics, which is jointly run by the Max Planck Society and the University of Hanover.

BBC: Lab tuned to gravity's 'ripples'