Cosmic Rays and Exploding Stars

Scientists have known about cosmic rays for a century. But these high-energy subatomic particles, which stream through space at nearly the speed of light and crash into the Earth’s upper atmosphere, have been mostly a mystery. The primary reason: researchers have been unable to tell where they come from, or how they’re born. But new research has shed new light on the origins of cosmic rays: supernovae. (Read our article about this discovery).

Today, Thursday, Feb. 28,at 20:00-20:30 UTC (12:00-12:30 p.m. PST, 3:00 pm EST) Dr. Stefan Funk of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) will answer questions from the web. He led the research team that was able to track gamma rays — the most energetic form of electromagnetic radiation, or light — back to the remnants of supernova explosions, using the Fermi Gamma Ray Telescope. The finding offers the first astrophysical evidence for how cosmic rays are produced, as well as where they are generated: in the shock waves that emanate from an exploded star.

Science writer Bruce Lieberman will moderate the webcast and ask your questions about the new data on cosmic rays. Questions can be submitted via Twitter (use the hashtag #KavliAstro) or email (info@kavlifoundation.org).