Number 194 (Story #2), September 13, 1994 by Phillip F. Schewe and Ben Stein THE SOLAR SYSTEM SITS IN AN INTERSTELLAR CLOUD. The existence of the cloud and its geometry can be deduced from its effect on the spectra of nearby stars and cosmic rays. Priscilla Frisch of the University of Chicago calculates, further, that our solar system first encountered the cloud (moving at right angles to it) between 2000 and 8000 years ago. (Priscilla C. Frisch, Science, 2 Sept.)