PLANETARY SYSTEMS IN THE MAKING have been discovered in the form of tenuous dust disks surrounding several more stars. Astronomers believe that our own solar system evolved out of such a disk of material left over after the formation of the sun. Previously a disk like this had been found around the star Beta Pictoris. Now a report in Nature (23 April) reveals disks around two more stars, Formalhut and Vega. Yet another, around the star HR4796A, was announced at a NASA press conference on 21 April. Formalhut's disk even has a dust-free inner zone which one would have expected if rocky planets formed there had swept all such material for their own use. The observations are possible because of new infrared detectors sensitive to the radiation emitted by the relatively cool dust.