Mount Wilson Observatory

Where we discovered our place in the universe. Home to the 60 & 100-inch telescopes, as well as the CHARA Array.

[Mount Wilson Observatory @MtWilsonObs]

Sat, Nov 7 | Sunset–1AM
Join Mount Wilson Observatory and LAAS for our final FREE star party of the season! See Saturn, Andromeda, the Pleiades, nebulae, and star clusters. Donations welcome!
More info: https://t.co/MVt4SHrB3j

[Caltech @Caltech]

President Ray Jayawardhana drew on Caltech's history of scientific daring to outline three aspirations for the Institute's future.

Read more: https://t.co/IfeYsN4l6t

[Carnegie Science @carnegiescience]

Since Jan. 4, 1917, observers at Mount Wilson Observatory’s 150-foot solar tower have drawn the Sun’s surface every clear day. #Carnegie125

Find more info and the link to @mtwilsonobs' digital archive in the full story: https://t.co/oOeUAMNsGf

[Mount Wilson Observatory @MtWilsonObs]

Mount Wilson Observatory will be closed for roadwork from 6 PM Tuesday, October 27, through 8 AM Thursday, October 29. We look forward to seeing you this weekend!
Cosmic Café: Sat 10–5, Sun 10–4
Docent Tours: 11:30 AM & 1 PM both days.
See you on the mountain!

[Mount Wilson Observatory @MtWilsonObs]

Just a few tickets left! Join us this Sat, Oct 17 for our final Talks & Telescopes of the season. Hear Observatory history from founder George Ellery Hale’s grandson, Sam Hale, then observe through our historic 60-inch & 100-inch telescopes!
🎟️ https://t.co/8Qi9HJp4EO

[Mount Wilson Observatory @MtWilsonObs]

A special evening closes our 2026 Talks & Telescopes season Oct 17. Sam Hale, grandson of founder George Ellery Hale, shares a personal look at his grandfather’s remarkable life & legacy—followed by observing on the historic 60- & 100-inch telescopes.
🎟️ https://t.co/JgvoX5MkEM

[Mount Wilson Observatory @MtWilsonObs]

What a way to close out the season! A sold-out crowd filled the 100-inch dome for our final concerts of 2026, ending the afternoon on their feet, cheering the piano quartets. Thank you to our musicians, audiences & Artistic Director Cécilia Tsan. See you in the dome in 2027!

[Mount Wilson Observatory @MtWilsonObs]

Something strange is happening on the mountain… 🌱 Visitors are advised to avoid any unusually large seed pods...Join us for our final Matinee on the Mountain of 2026: Invasion of the Body Snatchers (1956).
Oct 10 | 3 PM 🎟️ https://t.co/MYEcXZeQQk

[Mount Wilson Observatory @MtWilsonObs]

On Oct. 5, 1923, Edwin Hubble began the night at Mount Wilson’s 100-inch telescope that helped reveal a universe beyond the Milky Way. 103 years later, Rep. @RepJudyChu introduced a resolution designating Oct. 5 as National Beyond the Milky Way Day.
🔗 https://t.co/erw7G2iG8M

[Mount Wilson Observatory @MtWilsonObs]

One last movie on the mountain! 🎬 Our 2026 Matinees on the Mountain season closes Oct 10 with the 1956 sci-fi classic Invasion of the Body Snatchers - filmed in part in Sierra Madre, just down the hill from Mount Wilson!
🎟️ https://t.co/gnnprwa9EN

[Mount Wilson Observatory @MtWilsonObs]

Only a few Saturdays remain to see Nocturnal Landscapes From the Arid West at Mount Wilson. See Russell Crotty’s work inspired by the night sky & landscapes of the American West inside the historic 100-inch telescope dome.
Saturdays 1–5 PM | Through Oct 17
https://t.co/ND6rLLp551

[Mount Wilson Observatory @MtWilsonObs]

Our final concert of the season! Hear Mahler & Brahms in the historic 100-inch telescope dome - your last chance this year to hear our beautiful donated piano in this remarkable space.
Oct 4 | 3PM & 5PM
🎟️ https://t.co/JT2SqRPBJF

[Mount Wilson Observatory @MtWilsonObs]

More than a century separates these views of Mount Wilson’s 100-inch telescope dome - but from this angle, remarkably little has changed. Today, visitors can still follow the same path to the dome. Come see it for yourself!

[Mount Wilson Observatory @MtWilsonObs]

Only 2 chances left this season!
Go behind the scenes with Mount Wilson’s 60- & 100-inch telescopes: explore their mechanical systems, see the motion controls in action & visit areas normally off-limits to the public. Tix available for Sep 26 & Oct 24
🎟️ https://t.co/QP1WB5cEKa

[Mount Wilson Observatory @MtWilsonObs]

Spend an evening under the stars at Mount Wilson! Sept 19: a special talk on Henrietta Leavitt, sunset on the mountain, and a night of observing through our historic 60- & 100-inch telescopes. Bring a picnic or grab dinner from the food truck!
🎟️ https://t.co/uRhbZpZjpD

[Mount Wilson Observatory @MtWilsonObs]

This Saturday: Solaris on the mountain!
Join us Sept. 12 for Tarkovsky’s haunting sci-fi classic Solaris (1972). Come early, grab lunch at the Cosmic Café, explore the Observatory, then settle in for a movie on the mountain.
🎟️ https://t.co/21SSXQQ3Ry

[Mount Wilson Observatory @MtWilsonObs]

Solaris on the mountain! Join us Sat Sept. 12 for Tarkovsky’s sci-fi classic about a mysterious planet, an alien intelligence - & memories that refuse to stay in the past. Come early for lunch at the Cosmic Cafe & explore the Observatory before the show. 🎟️https://t.co/21SSXQQ3Ry

[Mount Wilson Observatory @MtWilsonObs]

This Sunday, Sept. 6, the Webern String Quartet performs Todd Mason’s The Phoenix and Beethoven’s String Quartet No. 15 beneath the historic 100-inch telescope. Join us for the second-to-last concert of the season in this extraordinary space! 🎟️ https://t.co/qGam7dpGgr

[Mount Wilson Observatory @MtWilsonObs]

🔭 FREE Star Party this Friday, Sept. 4! Join Mount Wilson & @LAAstroSociety from sunset–1AM for a night of stargazing. Saturn after 9PM, with Andromeda, globular clusters & the Ring Nebula also in view if skies are clear. No RSVP required! More info: https://t.co/XiMjJdLpAg

[Mount Wilson Observatory @MtWilsonObs]

Just two months left in our 2026 public event season! September brings stargazing, live music in the 100-inch dome, Solaris, Talks & Telescopes, behind-the-scenes Engineering Tours, art & more. Come spend a day (or night!) on the mountain.
https://t.co/6DFaIyPmex