Cosmic rays are tiny bits of atoms racing by us — and even sailing right through our bodies — all the time. Physicists can’t figure out where they came from, but they have some wild hypotheses: | Vox

🔦 New data from NASA’s NuSTAR space observatory indicate that cosmic X-ray emitters called ultraluminous X-ray sources may look dramatically different based on whether they point toward or away from Earth. go.nasa.gov/3wpxCdL | NASA Jet Propulsion Laboratory