Astronomers have just made an incredible discovery: a glowing cloud of energetic particles that stretches nearly 20 million light-years across space.
This massive structure surrounds a huge group of galaxies known as a galaxy cluster, and it’s the largest of its kind ever found.
Even more surprising, scientists believe it isn’t powered by stars or galaxies—but by shockwaves and turbulence in the space between them.
The galaxy cluster is called PLCK G287.0+32.9 and lies about 5 billion light-years from Earth. It was first discovered in 2011, and earlier studies had spotted two bright radio “relics” at its edges—likely caused by giant shockwaves.
But now, using new radio telescope images, scientists have found something much more impressive: a faint but enormous radio glow that wraps around the entire cluster.
This glow is a sign of high-energy particles and magnetic fields spread across a vast region, far beyond what previous studies had detected.
Dr. Kamlesh Rajpurohit, the lead scientist on the project from the Center for Astrophysics | Harvard & Smithsonian, said the team expected to see the two bright edges again, but they were stunned to find the whole cluster glowing.
He explained that a cloud this size—almost 20 times wider than our Milky Way—had never been observed around any galaxy cluster before.
At the heart of this discovery is a radio “halo,” a huge bubble of radiation about 11.4 million light-years across. What makes this even more exciting is that it was seen at a radio frequency where such halos are usually invisible. This suggests something unusual is energizing the particles throughout the cluster.
Normally, these energetic particles lose power over time and fade, but in this case, the particles still appear active across the entire region. Scientists think giant shockwaves or swirling turbulence in the hot gas between galaxies might be giving them a fresh boost of energy. However, this is just a theory for now, and more research is needed to know for sure.
The discovery not only challenges what we thought we knew about how these particles stay energized, but it also opens up new ways to study cosmic magnetic fields—one of the biggest mysteries in space science. These fields may play a key role in shaping the universe on its largest scales.
X-ray images from NASA’s Chandra Observatory reveal even more strange features in the cluster, including boxy shapes and comet-like tails. These may be signs of violent collisions between galaxy clusters or eruptions from supermassive black holes, adding to the drama of this colossal cosmic environment.
This record-breaking find reminds us that the universe still has many secrets to uncover.
