Copyrighted photo courtesy of Norm Vargas.
The 100-inch Hooker Telescope, the world's largest from 1917 to 1949, forever altered our understanding of the nature and size of the Universe and launched a revolution in astronomy that continues through today. This world-heritage class instrument, used by many of the greatest astronomers of the Twentieth Century, is for the first time being made available for regular public viewing. Imagine looking through the telescope used by Edwin Hubble in the 1920s to measure the expansion of the Universe...
To help visualize an evening at the 100-inch telescope, our spherical panorama virtual tour shows three views of the telescope at vantage points from which you can scan in all directions.
For instructions on how to request an observing session on the 100-inch telescope, click Visitor Information below, and then refer to the sections Requesting Viewing Through the 100-inch Telescope and Viewing Fee. The 2016 fee rates are $2700 per half night and $5000 per full night for a group of up to 18 people.
Before requesting a specific date, please check the Calendar of Available Nights below, to see if the night you are interested in visiting is available. All unavailable nights are marked with an "X."
Please note that nights are scheduled either for the first half of the night or for the full night, based upon the calendar date of the beginning of the session. To request a half or a full night, simply check the appropriate space for "first half" or "full night" on the 100-inch Telescope Time Request & Agreement Form below. Before submitting this form, you must first send an email inquiry to the Telescope Coordinator to make sure your night is indeed available.
We are able to schedule a half night of observing for the first half of the night only. Logistical problems preclude us from scheduling two different groups for the first and second halves of the night. We also do not provide a service for matching different groups to share the same reservation. Occasional individually-ticketed nights are announced during the season from this website and from our Facebook page.
Please read the Visitor Information section below carefully.
For further information about observing at the 100-inch telescope, contact the Telescope Coordinator. For separate information regarding daytime tours of the Observatory, please check here. Current weather and road conditions are available here.