Whence comets?
Recent advances in cometary science have indicated the importance of mixing of materials in the disk where the planets of our solar system formed. Now, the results from the Stardust Discovery Mission unambiguously show that even more extensive and earlier mixing of the material took place, raising new challenges for theories of the protoplanetary disk and the formation of comets.
A'Hearn
Michael F
MF
Department of Astronomy, University of Maryland, College Park, MD 20742-2421, USA. ma@astro.umd.edu