Jonathan C. Tan

In the dense gaseous cocoon around a young massive star, streams of matter collide as if in a giant chemical flask. One stream moves relative to us at about 11 kilometers per second, the other at about 5. The telescope at Onsala (Sweden) caught their radio voices and resolved them into hundreds of spectral lines — molecular fingerprints.

In a dense cloud of gas and dust where massive stars are born, two young stars recently passed very close to each other. Their dance has lasted only about sixty years, and astronomers have now seen it in detail for the first time.