The cosmos has plenty of terrifying Lovecraftian features, but one of my favourites is the Space Roar. There is a loud radio signal, described as a constant hiss, that seems to pervade the cosmos. It is louder than the radio signature of radio galaxies, and it is without explanation.
I have a space question. I know about the Roche limit but is there an upper limit to how big a ring can get compared to its planet? Asked by Dan Of course there are limits, the Universe is all about limits! But they're not as strict as one would think. We have found an object in 2012, J1407b, with a ring system 200 million kilometres in diameter. If the rings were centred on Earth they would cover the inner solar system all the way to the orbit of Mercury on the opposite side of the Sun.