Some facilities are on remote mountaintops, such as the University of Denver's Mt. Evans Meyer-Womble Observatory, billed as the "Highest Operating Observatory in the West," at 14,148 feet. (Currently, the observatory was not operational because it was still recovering from disastrous high winds that damaged the dome and the telescope during the 2011–2012 winter season.)
Certain observatories are dedicated to public education and information; cities, counties, school systems, or nonprofit organizations often operate these facilities. Here are some of the top sites:
- The Royal Observatory Greenwich, in London, England: One of the most famous observatories in the world, at one time the Royal Observatory was a professional research facility, then called the Royal Greenwich Observatory. The observatory is "home" of the prime meridian, from which longitude is measured around Earth. Equally important, it was the original source of Greenwich Mean Time, which set the standard for timekeeping worldwide.
- Lowell Observatory, on Mars Hill in Flagstaff, Arizona: Research observatories vary in the degree to which they accommodate visits from the public, but Lowell is especially welcoming. You can even look at planets or stars on some nights: The observatory advertises that you can "Peer through the telescope that Percival Lowell used to sketch Mars or visit the telescope that helped Clyde Tombaugh discover Pluto." (However, the latter telescope was removed from its dome in 2017 for about a year's worth of renovations.) Lowell has a fine visitor center with a theater and exhibit hall and offers frequent tours.
- The National Solar Observatory, at Sunspot, New Mexico: This observatory runs Sun-watching telescopes in Lincoln National Forest above the little town of Cloudcroft, which is high above the city of Alamogordo. You can check out its Sunspot Astronomy and Visitor Center (daytime visits only) and take a tour of the observatory as well.
- Mount Wilson Observatory, in the San Bernardino Mountains above Los Angeles, California: Mount Wilson, where the expansion of the universe and the magnetism of the Sun were discovered, is a landmark in the history of science. Albert Einstein was a special guest there, but you don't have to be a Big Brain to enjoy your visit. Self-guided tours are free; guided tours occur, for a fee, on Saturdays and Sundays. For a (high) price, you and your friends can even pool your money and book viewing time on the 100-inch telescope, which Edwin Hubble used to discover that the universe extends far beyond the Milky Way.
- The Griffith Observatory, in Los Angeles, California: This observatory is operated entirely for the public at Griffith Park in Los Angeles, offers planetarium shows and nighttime sky viewing, and is well worth visiting.
- Palomar Observatory, near San Diego, California: Here you can see the famous 200-inch telescope that, for decades, was the largest and best in the world. Now, with new instrumentation, the telescope is still a great contributor of astronomical knowledge. You have to guide yourself around the observatory grounds. Check the website just before you visit; the facility closes well before sunset and is often off limits on short notice due to road and weather conditions near the summit. The observatory has a small museum and gift shop.
- Kitt Peak National Observatory, on a Native American reservation (the Tohono O'odham Nation) in the Sonoran desert, 56 miles west of Tucson, Arizona: When I worked at Kitt Peak during the 1960s, tourists were permitted to visit only during the day. Even so, there was a lot to see, from the visitor center (an astronomical museum) to the many telescope domes. Things have changed now, so put KPNO high on your list when you visit the American Southwest. During the day, you can take part in a guided or self-guided tour. You can also experience nighttime observing with certain KPNO telescopes. You must make an appointment for observing in advance. For details, go to the website and click "Visiting Kitt Peak." Important: You will likely pass through a border control checkpoint on your way to Kitt Peak, and foreign visitors will need to show their passports.
- MMT Observatory, on Mount Hopkins in the Coronado National Forest, 37 miles south of Tucson, Arizona: Check in at the Fred Lawrence Whipple Visitor Center at the base of the mountain, where you can enjoy exhibits and sign up for tours of the observatory, with its 256-inch (6.5-meter) reflecting telescope, one of the largest in the continental United States. But before you go, check the MMT public tours website to find when the visitor center is open, when tours are offered, and what they cost.
- Mauna Kea Observatories, on the Big Island of Hawaii: The biggest "telescope farm" in the United States is home to 13 large telescopes operated by the United States and other nations. (The only comparable assemblage of big telescopes on Earth is the European Southern Observatory in Chile.)
Mauna Kea is well worth visiting, but you need to be in good health, due to the high altitude (13,796 feet), and follow the "Visiting the Summit" instructions at the website. There's also a visitor information station at 9,200 feet, where you should start your visit and where you can participate in the nightly stargazing program.
- The National Radio Astronomy Observatory's Very Large Array (VLA) in New Mexico: Drive across the Plains of San Agustin, near Socorro, to see the huge radio telescope array, a system of 27 dish-shape radio telescopes, each 82 feet in diameter. Jodie Foster filmed scenes for the movie Contact here. Check out the visitor center and gift shop, but if you want a tour, you have to come on the first Saturday of the month.. You pay a modest fee unless you're fortunate enough to attend one of the twice-yearly open houses.
- Green Bank Observatory: At Green Bank, West Virginia, nestled among mountains in the United States National Radio Quiet Zone, you can tour the 328-foot Robert C. Byrd Green Bank Telescope, which is the world's largest fully steerable dish antenna. The Green Bank Science Center offers interactive exhibits, and it's the starting point for public tours (a fee applies). After taking in the sights, stop by the Starlight Café to treat yourself to tasty refreshments.
- Jodrell Bank Observatory, near Goostrey, Cheshire, England: At this observatory, operated by the University of Manchester, you can see the historic 250-foot Lovell Telescope, a big dish once used to bounce radar signals off Soviet booster rockets and even off the Moon. The Jodrell Bank Discovery Centre offers a Space Pavilion, Planet Walk, Galaxy Maze, and a large clockwork orrery (mechanical model of the solar system, with moving planets). It's closed on some holidays, so check the website before you go.
- Parkes Radio Telescope, near Parkes, New South Wales, Australia: The radio telescope to visit when you're Down Under is the 210-foot, dish-shaped Parkes Radio Telescope. The telescope is known to astronomers for research findings, but it achieved its greatest public notice when it relayed radio transmissions to NASA from Apollo astronauts on their missions to the Moon. The Parkes Radio Telescope Visitors Discovery Centre has exhibits, a 3-D theater, and the aptly named Dish Café.