Van Webster of the Local Group Astronomy Club will present a fascinating lecture on how the Mount Wilson observatories above Pasadena expanded our knowledge of the universe.

The presentation, “Mt. Wilson Observatories – History and Discoveries,” will take place at the Santa Clarita Valley Senior Center on Thursday, Sept. 17, from 1 p.m. to 2 p.m. The Senior Center is located at 22900 Market Street in Newhall. Admission is free. For information contact Robin Clough at 661.259.9444 or rclough@scv-seniorcenter.org.

In the first half of the 20th century, eminent astronomers such as Harlow Shapley and Edwin Hubble used the incomparable facilities of Mount Wilson Observatory to forever alter humankind’s view of our place in a vast and expanding Universe. Today, Mount Wilson’s original solar and night-time telescopes, the world’s largest for two generations of astronomers, have been joined by new facilities achieving unprecedented high-resolution views of the stars.

The observatory contains two historically important telescopes: the 60-inch (1.5 m) Hale telescope built in 1908 and the 100-inch (2.5 m) Hooker telescope, which was the largest telescope in the world from its completion in 1917 until the 200-inch Hale Telescope at Palomar Observatory was built in 1948.