A 14-year time-lapse reveals the violent, high-energy dance of our invisible universe
NASA’s Fermi telescope has captured the gamma-ray sky in a stunning 14-year time-lapse. From our own Sun’s occasional flares to distant black holes firing jets of matter across billions of light-years, this map reveals the most energetic events in the cosmos, showing a universe that is constantly flickering, erupting, and changing.
The Fermi Gamma-ray Space Telescope, managed by NASA’s Goddard Space Flight Center, has spent over a decade mapping the highest-energy form of light. Between August 10, 2008, and August 2, 2022, the Large Area Telescope (LAT) collected data on gamma rays with energies exceeding 200 million electron volts. For perspective, this dwarfs visible light, which typically registers between 2 and 3 electron volts. By processing this data into a rectangular map, researchers have created a visual record of the sky’s most intense activity.
At the center of the map lies the Milky Way, glowing brightly as cosmic rays—particles traveling near the speed of light—collide with interstellar gas and starlight. The band is also speckled with pulsars and supernova remnants. Our own Sun appears as a moving source, tracing a path across the sky due to Earth’s orbit. While usually faint, the Sun occasionally erupts in solar flares, briefly becoming one of the brightest gamma-ray sources in the sky.
Beyond our galaxy, the map reveals distant, rapidly changing sources known as blazars. These are galaxies hosting supermassive black holes with masses equivalent to millions of suns. These black holes launch jets of matter at near-light speed; when these jets point toward Earth, their brightness and variability are significantly enhanced. Because these galaxies are incredibly remote, the light we see today often represents events from billions of years ago. For instance, flares from the blazar 4C +21.35 occurred 4.6 billion years ago, coinciding with the birth of our own solar system.
This time-lapse is a product of a vast international collaboration involving the U.S. Department of Energy and partners across France, Germany, Italy, Japan, and Sweden. While the current map captures long-term trends, Fermi also monitors short-duration events like gamma-ray bursts. By alerting other telescopes to sudden flares, Fermi serves as a critical node in a global network, helping scientists observe and understand the most powerful cosmic explosions as they unfold.
