In data collected by a powerful radio telescope, astronomers have found what appears to be a perfectly spherical bubble. A large international team has named the object Teleios, after the ancient Greek for "perfection".
Radio astronomers see what the naked eye can't. As we study the sky with telescopes that record radio signals rather than light, we end up seeing a lot of circles.
The James Webb Space Telescope has turned its golden gaze to Cassiopeia A, a spectacular, complex, expanding cloud of hot gas billowing out from a star humanity saw go supernova back in the 1670s.
