Credit: DAMPE Collaboration Dark Matter Particle Explorer (DAMPE) Collaboration directly observed a spectral softening of helium nuclei at about 34TeV for the first time. This work was based on measurements data of the helium spectrum with kinetic energies from 70 GeV to 80 TeV (17.5 GeV/n to 20 TeV/n for per nucleon) recorded by the DAMPE. The relevant results were published in Physical Review Letters. Galactic cosmic rays (GCRs) offers important ways to deeply understand the astrophysical particle origin and accelerators and the interstellar medium of the Galaxy. Helium nuclei, the second most abundant nuclear element of cosmic rays, is a distinguishing feature of space.