Astronomers have discovered four circles of radio waves in space, but have no explanation for their origin. We don’t even know how big or far away they are
Source:
https://www.newscientist.com/article/2247978-circles-in-space-made-of-radio-waves-are-like-nothing-weve-ever-seen/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home