On this day in 1970, a landmark paper showing the 3D reconstructions of spherical viruses was published. On day 122 of #LMB365, an electron micrograph of human wart virus is shown, alongside a version with its surface lattice superimposed on top. Aaron Klug led a group of LMB scientists applying the technique he had developed just a few years early, of computing 3D density maps from electron micrographs, to spherical viruses. The tecnique produced clear reconstructions of the surface structures of viruses, and paved the way for 3D imaging by electron microscopy. Reference: R. A. Crowther, Linda A. Amos, J T. Finch, D J DeRosier, A. Klug. Nature 226: 421-425.