A South African university is injecting rhino horns with radioactive isotopes in an effort to combat poaching. The Rhisotope Project, a collaboration between the University of the Witwatersrand, nuclear energy officials, and conservationists, involves injecting rhinos with isotopes detectable at borders and airports. Organizers claim the isotopes are harmless to the animals. The project aims to make rhino horns easier to trace, even in large shipments, thus deterring illegal trade. Five rhinos have already been injected as part of the initial phase, with hopes to expand the program to a larger portion of the rhino population.