For decades, astronomers have thought that planets form out of the rotating disks of debris that encircle most newly formed stars. Within these so-called protoplanetary disks — which can be up to 1,000 astronomical units wide (1 AU is the average Earth-Sun distance of 93 million miles) — particles of gas and dust clump together over time, slowly but surely forming larger bodies that may eventually reach planetary status. However, despite years of searching, astronomers have so-far failed to