DEARBORN OBSERVATORY

In 1863, the Chicago Astronomical Society and the University of Chicago purchased a 47 cm diameter lens for $18,187 to begin construction of an observatory. This construction was financed by Jonathan Young Scammon (1812-1890), a wealthy businessman who imposed the name of his deceased wife, Mary Ann Haven Dearborn, as the name. In 1864, the objective was delivered to the observatory in Chicago and the first observations were made two years later. For more than 20 years, the rate of observations was high, but in 1886 the university went bankrupt! The telescope then became the exclusive property of the Chicago Astronomical Society; it was moved to Northwestern University where it is still located today, although its current location is not exactly the one originally chosen. With time and the natural wear and tear of the mechanical parts of the main building, the dome was replaced (in 1997) and its infrastructure renovated.

What is remarkable about this observatory is that its main instrument, the 47 cm telescope, is still used today for students but also and especially for public observations! Due to the high level of light pollution on the site - we are here in the northern suburbs of Chicago - the observations made focus on bright objects, especially the Moon and planets.... On an evening when the atmosphere is calm and the images stable, it is possible to contemplate exceptional details in the tormented atmosphere of Jupiter, on the surface of Mars, or to discover very fine details in the most beautiful lunar craters.