Astronomers around the world are captivated by an unusually bright and long-lasting pulse of high-energy radiation that swept over Earth Sunday, Oct. 9. The emission came from a gamma-ray burst (GRB) – the most powerful class of explosions in the universe – that ranks among the most luminous events known. On Sunday morning Eastern time, a wave of X-rays and gamma rays passed through the solar system, triggering detectors aboard NASA's <a href="https://www.nasa.gov/content/fermi-gamma-ray-space-telescope">Fermi Gamma-ray Space Telescope</a>, <a href="https://www.nasa.gov/mission_pages/swift/main">Neil Gehrels Swift Observatory</a>, and <a href="https://www.nasa.gov/wind">Wind spacecraft</a>, as well as others. Telescopes around the world turned to the site to study the aftermath, and new observations continue. This sequence constructed from Fermi Large Area Telescope data reveals the sky in gamma rays centered on the location of GRB 221009A. Each frame shows gamma rays with energies greater than 100 million electron volts (MeV), where brighter colors indicate a stronger gamma-ray signal. In total, they represent more than 10 hours of observations. The glow from the midplane of our Milky Way galaxy appears as a wide diagonal band. The image is about 20 degrees across. Image credit: NASA/DOE/Fermi LAT Collaboration #NASAMarshall #NASA #Fermi #FermiGamma-raySpaceTelescope #Swift #SwiftObservatory #gammarayburst #GRB