Posted: Sat, Jan 6, 2001, 12:38 AM ET (0538 GMT)
Gas giant planets around other stars may be more plentiful than previously believed. In a paper published in the journal Nature, European and American scientists said they detected traces of molecular hydrogen -- enough in some cases to make several Jupiters -- in the remains of protoplanetary disks around three young stars, even though existing models predicted no hydrogen should be left in the disk. Astronomers now believe hydrogen may last in such disks for up to 20 million years, several times longer than once thought, making it more likely that planets can form. Astronomers used data from ESA's now-defunct Infrared Space Observatory to directly detect the hydrogen at long infrared wavelengths, rather than rely on indirect measurements used in the past that now turn out to have been flawed. NASA's SIRTF telescope, scheduled for launch in July 2002, should provide even better data from more protoplanetary disks.

Related Links:

•  ESA press release
•  Caltech press release