Sunday, September 14, 2025 at 9:00 AM to 2:30 PM
Mount Wilson Observatory, Mt Wilson
#### ***Come see the inner workings of the most productive observatory in history!*** This special, behind-the-scenes tour concentrates on the mechanical, optical, and electrical details of our 60- & 100-inch reflector telescopes with demonstrations of their motion controls. The tour also includes the Snow Solar Telescope, the powerhouse, and the machine shop. The engineering that went into the 60- & 100-inch telescopes, both the biggest in the world for their time periods, represented the cutting edge of technology when they opened in 1908 and 1917 respectively. The Snow Solar Telescope, the first instrument constructed on Mount Wilson, established the world’s first consistent scientific study of the physics of the sun and was also the largest instrument of its kind between 1905 and 1908. It is still the oldest permanently installed working solar telescope in the Western Hemisphere. The powerhouse is where, in the early years, all power to run the observatory was produced. The adjoining machine shop is an example of a nearly 100-year-old facility used to repair or fabricate parts to keep the telescopes operating. ### Tickets: $100 [](https://mtwilson.app.neoncrm.com/np/clients/mtwilson/event.jsp?event=19313&) Please note: All ticket sales are final. We’re unable to offer refunds, exchanges, or transfers. Thank you for understanding! (unless we must cancel due to unforeseen circumstances). *If you receive the message REGISTRATION CLOSED, this means the event has sold out.* [**Maps & Directions.**](https://www.mtwilson.edu/1map/) When you arrive, please park in the upper parking lot. Tour participants will then be escorted in. #### TOUR SCHEDULE: **9:00 – **Arrival at the Observatory. Please arrive early, rather than late. The gate to the Observatory will open at 8:30. **9:15 – **Tour Begins with visits to the 60-inch & 100-inch Telescopes. **12:15 – **Break for lunch (bring your own!). **1:00 – **Visit to the Snow Solar Telescope. **1:40– **Visit Power House and Machine Shop **2:30 – **Engineering Tour ends. #### BE AWARE: **We will hold the tour rain or shine.** If we decide to cancel a tour due to severe weather, we will reschedule or issue refunds. **The tour size is limited to 10 people** so that all participants may fit into the smaller mechanical areas beneath the telescopes. **The minimum age** is 12. **A Forest Service Adventure Parking Pass is NOT required** to park for this tour. **Please bring** water and plenty of food for lunch and snacks. **Be warned; you may get some grease on yourself!** Wear old, comfortable clothing and close-toed shoes. Bring an extra layer or two, as it may get chilly on the mountain in the spring and fall. **This tour involves** several staircases and a good deal of walking around the observatory grounds. The century-old facilities are unfortunately not ADA-compliant. Those with cardiac, respiratory, or mobility issues should not attend.