There may be an ultraheavy explanation for the mystery surrounding the origins of the highest-energy particles ever observed.

A long-standing cosmic mystery is beginning to yield new clues as researchers uncover a strikingly consistent pattern in the ...

On April 30, two major observatories reported breakthroughs in understanding extreme cosmic particle acceleration. China's LHAASO detected ultra-high-energy gamma rays from a binary star system, while ...

Cosmic rays (CRs) are energetic particles traveling through space at speeds close to that of light. They consist of atomic nuclei, electrons, positrons, high-energy gamma rays, and neutrinos, and are ...

Fading candle: remnant of a type Ia supernova called SNR 0509-67.5. (Courtesy: NASA/CXC/SAO/J Hughes et al/ESA/Hubble Heritage Team) The mysterious substance known as dark energy thought to be pushing ...