Ground - based spectroscopy can then measure planet masses, while space - based spectroscopy can characterize their atmospheres. (spaceflightinsider.com)
Now we know that it was probably only about a tenth the mass of our planet (newscientist.com)
The disk transport rates range up to 1e - 7 solar mass per year and scales with planet mass to the power of 3/2. (eos-nexus.org)