Public Night at Chamberlin Observatory. For Information go to: http://www.denverastro.org/publicnights.html Some of the Denver Astronomical Society's brightest and most enthusiastic individuals lead Public Nights each Tuesday and Thursday at DU's Historic Chamberlin Observatory. Public Nights are a Denver tradition that began on the night of August 1, 1894. The Denver Astronomical Society has hosted Public Nights for over 60 years.