There is a paradox in the universe: scientists consider that there are millions more giant black holes in the cosmos than we know about, and yet, if they are there, how would they stay hidden? Well, it turns out they do so by hiding in something extremely common in our universe. They’ve been hiding in the gas clouds. Not just regular clouds, however—highly dense coatings of cloud and gas so heavy that merely X-rays can escape. Which is why, by directing NASA’s NuSTAR X-Ray telescope into those clouds, scientists in the UK’s Durham University were able to approve something they had beforehand only supposed: Behind that extremely dense layer of clouds and gas were five amazingly active, supermassive black holes... and they consider those five were only the start.
|Image: Hubble picture of one of the clouded over black holes / Hubble Legacy Archive, NASA, ESA., next to an artist’s concept of the black hole, minus the clouds / NASA, ESA.|