NuSTAR explores the hidden lairs of black holes

NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) recently recorded some of the "biggest and baddest" black holes in nine known galaxies. These monsters are actively devouring material, but their hidden nature makes observing them a challenge. Usually buried underneath a thick blanket of gas and dust, scientists are now able to observe these super massive black holes.

Clear observations were not possible before NuSTAR -- which launched in 2012 -- and has allowed scientists to learn why some black holes only appear obscured and why they are more active than previously thought.

Related: NASA: Black holes make perfect lab for dark matter