The appearance and perception of comets through the ages and across cultures will be explored at the University of Colorado at Boulder's Fiske Planetarium April 14 and 15. John Weiss, a CU-Boulder doctoral candidate in astrophysics, will present "Comets: More Than You Think" at 7:30 p.m. on both days. While comets are celebrated today, they mostly were feared in the past as portents of disasters, doom and the death of kings, according to Weiss.