Gas “waterfalls” down onto a forming planet in this artist’s illustration. (Credit: NRAO/AUI/NSF, S. Dagnello)

Stars and their planetary systems are born from clouds of gas and dust that collapse into swirling disks. Astronomers can’t directly see planets forming in these disks because they’re hidden in all the debris. But in the past few years, new kinds of telescopes have started to reveal gaps in disks around young stars where planets might be forming. 

Now, astronomers have seen gas f