Astronomers recently trained NASA’s Chandra X-ray Observatory on a strange radio formation that sits behind the dense band of stars, gas, and dust along the Milky Way’s plane. From our vantage the structure looks almost exactly like the musical symbol known as a treble clef, a resemblance that led researchers to call the whole scene the Treble Clef. Chandra and Germany’s eROSITA telescope both recorded the presence of gas heated to millions of degrees, the clear signature of a galaxy cluster, one of the largest objects in the universe. Further scrutiny of that gas showed the cluster is actually two separate clusters that ran into each other.