NuSTAR resolves the Galactic pulsar wind nebula G11.2-0.3 into a shell of high-energy emission (3--35 keV) surrounding a bright source at the center associated with the pulsar. The shell emits due to synchrotron emission as charged particles are accelerated within the magnetized flow from the supernova explosion that created the pulsar. NuSTAR shows evidence of particle acceleration in this shell, implying that this Galactic remnant is less than a few thousand years old. NuSTAR also sees the shell radius decrease with increasing energy, which is due to the shorter synchrotron lifetime for higher energy X-rays. The bright white central source shows the location of the pulsar itself, which is sending out a strong wind of particles that are accelerated in the surrounding environment. For more information, see the paper recently published in the Astrophysical Journal (https://ui.adsabs.harvard.edu/abs/2020ApJ...889...23M/abstract).