This survey and even more modern ones have shown that, Our Place in the Galaxy in our neighborhood of the galaxy, the stars are indeed evenly distributed in all directions. But from our vantage One hundred years ago, Mount Wilson astronomer point within an arm of the spiral, there is too much Harlow Shapley discovered our true position in the Milky obscuring gas and dust for us to see to the edges or the Way Galaxy. With a lucky chain of events, and lots of hard center of the galactic disk. We cannot see our own galaxy work, Shapley mapped the extent of our galaxy for the because we are inside it. TO PAGE 4 first time and showed that we were not at the galactic center, as most astronomers of the time supposed. Instead, he removed us to a position about two thirds of the way to its edge. In just a few years, he achieved a milestone in scientific understanding that ranks as the second act of the Copernican Revolution. When Mount Wilson Observatory was founded in 1904, humanity’s concept of our position in the Universe was limited. In fact, it had not changed much since Nicolaus Copernicus started circulating his ideas for a heliocentric universe with his first work, Commentariolus, or “Little Commentary,” sometime before 1514. For nearly four centuries after he removed the Earth from the center and replaced it with the Sun, most astronomers believed that our star was at, or very near, the center of things. Observing the band of stars that comprise the Milky Way, astronomers made careful star counts, which From a vantage point outside our galaxy, we would see our solar found roughly the same number in every direction. system embedded in a spiral arm, far from the center. Since we English astronomer William Herschel made a map of are unlikely to get such a view anytime soon, NGC 6744, was used. A barred galaxy visible from the Southern Hemisphere, it our position in the galaxy as early as 1785. Efforts to is is thought to closely resemble our own. Credit: ESO refine such surveys continued into the 20th century. Indeed, Dutch astronomer Jacobus Kapteyn, persuaded Mount Wilson Observatory director In this issue . George Ellery Hale to participate in a new survey called the “Selected Areas” program, in which a Our Place in the Galaxy .….1 STEM Program ……………..…..7 number of observatories would intensively sample 206 News + Notes …………………2 Observatory Visiting + Map….8 areas spread at regular intervals across the sky. This survey to chart the distribution of matter became one of the Become a Member! …………3 principle goals for the new 60-inch Telescope. Mount Wilson is Open to Visitors Weather and roads permitting, Mount Wilson Observatory will be open every day, except Christmas. Come on up to the mountain to enjoy the beautiful weather and uplifting surroundings! Until December 2, the Cosmic Café is open Saturdays and Sundays, 10 a.m. to 5 p.m., offering a variety of fresh-made sandwiches and other treats. At the Café you may purchase a National Forest Adventure Pass and tickets for the weekend walking tours. On other days the pass can be purchased at the gas station at the bottom of the Angeles Crest Hwy. After Dec. 2, our winter hours will be 10:00 am to 4:00 pm. See you on the top! ANNOUNCEMENTS A B O U T U S The Mount Wilson Institute NEWS + NOTES operates Mount Wilson Observatory on behalf of the CONCERTS AND TALKS AT MOUNT Carnegie Institution for Science. WILSON OBSERVATORY Mount Wilson Institute is dedicated to preserving the We have had a busy season on the mountain this Observatory for scientific research year, with many first time visitors coming up to and fostering public appreciation enjoy concerts in the 100-inch Telescope dome and of the historic cultural heritage of the Observatory. Reflections is science lectures in the auditorium followed by published quarterly by the Mount viewing through the 100-inch telescope. Check the Wilson Institute. website next spring for the coming 2019 events. INFORMATION TRIPLE MATCH For information about the Observatory, including status, With the help of many longtime supporters and new activities, tours, and reserving 60- friends, we surpassed our Triple Match goal by inch and 100-inch telescope time, $6,000 to raise a total of $78,000! (Trustee Michael visit our website: Horner generously matched the extra donations). We are well on our way to funding the much needed new mtwilson.edu public restrooms near the telescope domes. ✰ LOOK THROUGH OUR TELESCOPES REFLECTIONS STAFF Editor/Designer The 60-inch & 100-inch telescopes provide Robert Anderson incredible views of some of the most beautiful [email protected] objects in the night sky, and are the largest in the This is the second edition of world accessible to public viewing. For information Reflections published since Marilyn on how you can reserve time, available dates, fees, Morgan, our longtime, volunteer and to make reservations — visit www.mtwilson.edu editor passed in the spring. She was a and click on the “Observing” menu tab at the top. gi!ed, dedicated editor as we" as a Please note that we will not be taking reservations for kind human being. We miss her. 2019 until March 1st of next year. ✰ DON’T WANT TO MISS ANYTHING? The Triple Match was a success! For the use of historical Our 150-foot solar telescope photographs of Mount Wilson, we served as the “thermometer.” The Subscribe to Mount Wilson Observatory News for thank the Observatories of the Sunstar prisms at the top now Carnegie Institution for Science, updates on concerts, lectures, public telescope nights, shine the solar spectrum on the the Huntington Library, and other and other events. Sign up right from our website — city (see mtwilson.edu/sunstar). sources as noted. visit www.mtwilson.edu to find the link. Reflections copyright © 2018, Mount Wilson Institute PAGE ONE BANNER Help Sustain the Observatory PHOTOGRAPH The Observatory receives no regular support from government or (Inset) Astronomer Edwin Hubble institutions.We rely on donors, a few small grants, and the revenue from at the Newtonian focus of the our telescope nights to fund our continued operation.You can help 100-inch telescope on Mount ensure the continued operation of this science heritage site with your Wilson, circa 1923. tax-deductible gift. We welcome donations of any size and volunteer efforts of all kinds.Visit mtwilson.edu for information on how to support the Observatory through donations or volunteering. REFLECTIONS 2 NOVEMBER 2018 A LETTER FROM undergraduate research, public outreach, ongoing SAM HALE, CEO, scientific research, and restoration of our 114- year-old campus. MOUNT WILSON INSTITUTE We are just five years away from the centennial of Join the New Observatory Mount Wilson’s most well-known discovery, astronomer Edwin Hubble’s determination that all Membership Program! the faint “spiral nebulae” are really distant galaxies. We have many things we want to do to This year Mount Wilson Observatory and our prepare for this grand event in 2023. It is our goal many supporters made great strides in securing to bring the Observatory up to a more sustainable the future of this remarkable scientific site. We level by this time, so that we can properly held our first-ever triple match fundraiser and due showcase the incredible science that has been to the generosity of many new and longtime done in our own backyard, on this spectacular friends, we surpassed our goal, raising $78,000 mountain above Los Angeles. towards new public restrooms near the telescope domes. My deepest thanks to all who contributed, As 2018 draws to a close, please consider joining especially trustee Mike Horner, who agreed to us with a membership to get the new program off match all the money raised. We also received a to a great start. Sign up for an individual or family generous donation from trustee Michael Thacher membership, or a higher level named after one of to begin the renovation of the Monastery, which our famous astronomers. Sign up is easy at our housed many of the most famous astronomers of website: mtwilson.edu/membership the 20th century. We are a 501(c) non-profit, so your membership is We had a full season of events, including concerts tax-deductible. Our largely volunteer organization and astronomy lectures combined with an receives no regular support form government or opportunity to look through the famous 100-inch institutions. telescope. We celebrated the 150th anniversary of our founder, pioneering astrophysicist George As always, end-of-year donations are also Ellery Hale. Although he was my grandfather, I welcome, greatly appreciated, and are quick and continue to learn about the breadth and depth of easy via our website or mail: his many achievements—and all the things he made possible (such as Harlow Shapley’s 1918 Mount Wilson Institute discovery of our position in the Milky Way Galaxy, P.O. Box 94146 see the feature story). These events brought many Pasadena, CA 91109 people to the mountain for the first time. Inevitably, visitors are awed by what was accomplished here End the year on a high note with an inaugural and many want to help preserve the Observatory membership to Mount Wilson Observatory! and expand its programs. Thanks and Best Wishes for the Holidays, With this in mind, we are launching our membership program for those who would like to join us with ongoing support. By doing so, you can help us rebuild this historic mountaintop, so that it Sam Hale may inspire well into the future.