‘Ghostly sky circles’ that baffled astronomers might be explosions from distant galaxies

In 2019, my colleagues and I discovered spooky glowing rings in the sky using CSIRO’s ASKAP radio telescope in Western Australia. The rings were unlike anything seen before, and we had no idea what they were. We dubbed them odd radio circles or ORCs. They continue to puzzle us, but new data from South Africa’s MeerKAT telescope are helping us solve the mystery. We can now see each ORC is centered on a galaxy too faint to be detected earlier. The circles are most likely enormous expl