I thank Claes-Ingvar Lagerkvist and Karri Muinonen for their comments and general support. On specific topics I thank Per Magnusson for the shape and spin vector of 3 Juno , Thomas Müller for the colour correction of the IRAS data, and Karri for the Gaussian random surfaces. I also thank Dr. L. A. Lebofsky for his review.
© European Southern Observatory (ESO) 1998
Online publication: March 30, 1998