The paper version of the 2016 Calendar of the American Physical Society, sent to all the APS members, features a picture from a paper recently published by our team. The picture had been previously selected for the Phys Rev E Kaleidoscope (see News here) and illustrates the kinetic scale of the mushroom instability first described in “Transverse electron-scale instability in relativistic shear flows” by E. P. Alves, T. Grismayer, R. A. Fonseca, and L. O. Silva published in Phys. Rev. E 92, 021101(R) (2015).