3 Bay Area hikes about space, science in Sonoma, Stanford and Mt. Diablo

Very few of us will ever actually do a spacewalk, but the Bay Area is full of terrestrial hikes that will take you to noteworthy landmarks in the history of air and space.

There’s The Dish, used to communicate with spacecraft such as the Voyager missions to the outer reaches of our solar system, and surrounded by a 3.5 mile recreational trail just west of Stanford University.

You can head for Sonoma’s Sugarloaf Ridge State Park to see the Robert Ferguson Observatory and take a PlanetWalk – a 4.5-mile trail through a scale model of the solar system.

And then there’s the Mount Diablo Beacon, illuminated by Charles Lindbergh in 1928 as a U.S. effort to guide the first commercial aviators at night, before radio navigation became commonplace. Atop the mountain’s lofty summit, where you can see 40 of California’s 58 counties on a clear day, you’ll feel like you could practically give the International Space Station a passing high-five.

The Mary Bowerman Trail, Mount Diablo

Your heart may race on the Mary Bowerman Trail, a 0.7 loop that encircles Mount Diablo, just below its 3,849-foot summit.

The pounding pulse doesn’t come from the hike itself — the trail is mostly level — but from the way the route hugs the mountain’s contours, with the sky all around and steep drops to one side. You feel so high up, taking in views that reach in all directions, encompassing the entire Bay Area and even the white peaks of the Sierra Nevada on very clear days. It’s easy to understand why some Native American groups believed the mountain to be the birthplace of the world.

The hike excites the imagination in other ways, too, when you consider the mountain’s association with Charles Lindbergh, the dawn of 20th-century aviation and Lindbergh’s role as a forefather of the modern space program.

During the walk, the mountain’s historic Summit Visitor Center looms above along with its old navigation beacon, which sits atop the center’s stone rotunda and which Lindbergh helped to light.

On an April night in 1928, people parked at vantage points across the East Bay hills to look toward Mount Diablo and see an early 20th century technological wonder. Less than a year after Lindbergh became the first pilot to fly solo across the Atlantic, he pressed a telegraph key in Denver, sending a signal to the mountain beacon, which at the time was located atop a 75-foot tower built by Standard Oil. It was part of the Transcontinental Airway beacon system launched by NASA’s predecessor, the National Advisory Committee for Aeronautics.

Lindbergh’s signal told the beacon to flash its 10 million candle power beam of light, the Oakland Tribune reported at the time. Every night for the next decade or so, the light guided early air mail and commercial pilots, needing help navigating over the “hump” of the Sierra Nevada and into airports in the San Francisco Bay Area at night.

In going a bit down the Lindbergh rabbit hole, it’s amazing to consider how his nonstop, 33.5-hour flight from New York to Paris generated as much global excitement as the Apollo 11 moon landing would decades later. Lindbergh became a controversial figure in the 1930s for his isolationism and views on race. But he also used his new influence to garner support for the work of pioneering scientist Robert H. Goddard, credited with building the world’s first liquid-fueled rocket. After NASA was founded in 1958, Lindbergh was idolized by the agency’s first astronauts.

Just before Neil Armstrong’s 1969 moon landing, Lindbergh wrote an essay for Life magazine about seeing Goddard’s dream become “a reality” while watching the 1968 launch of the Apollo 8 mission. He said his body “staggered” at the sight of the Saturn V rocket lifting off: “Here one saw our civilization flowering toward the stars. Here modern man had been rewarded for his confidence in science and technology. Soon he would be orbiting the moon.”

Maybe it’s a stretch, but it’s possible to feel a fraction of Lindbergh’s awe while you visit the summit of Mount Diablo — considering also that the aviator later became an ardent conservationist who would no doubt appreciate its spectacular natural scenery.

Both the summit museum and the Mary Bowerman Trail, named for the celebrated botanist and co-founder of Save Mount Diablo, are dedicated to the mountain’s cultural and natural history. The trail, the first portion of which is ADA accessible, begins in a grove of scrubby oaks, then follows a path around the mountain, featuring an observation deck with benches and a viewing area equipped with high-powered telescopes. There’s lots to see closer in, including Eagle Peak and the Devil’s Pulpit, a towering red monolith.

After the hike, visit the visitor center museum and take in 360-degree views from the rotunda. The beacon was famously turned off after the Dec. 7, 1941, attack on Pearl Harbor and not relit until Dec. 7, 1964, when Fleet Admiral Chester Nimitz, commander in chief of Pacific Forces during World War II, attended a ceremony to commemorate those who survived and died on that “day of infamy.” Since then, the beacon shines on Dec. 7 every year. During the first year of the COVID-19 pandemic, Save Mount Diablo arranged to have it lit on Sundays to “bring our communities together and to remind people to look up at the light and of the healing power of nature.”

Take a hike: You can opt for the very ambitious hike or bike ride up to the summit, or drive up via one of Mount Diablo State Park’s two main gates ($10 vehicle-entry fee) along North Gate Road in Walnut Creek and Mount Diablo Scenic Boulevard in Danville. The Mary Bowerman Trail begins just east of the lower summit picnic area and parking lot; www.parks.ca.gov

Grab a bite: Pick up artisanal sandwiches, salads and other provisions for a mountain-top picnic at Danville’s Domenico’s Delicatessen, where the roasted turkey sandwich ($11.50) with pesto mayo is served on focaccia. Best enjoyed with the deli’s fresh-baked chocolate chip cookies. Open from 9 a.m. to 5 p.m. daily at 628 Hartz Ave., Danville; www.domenicosdeli.com.

The Dish, Stanford

It’s one of the most prominent landmarks on the Peninsula and among the most popular and accessible hiking trails in the region. And while passersby may assume The Dish is an old Cold War relic, it’s very much still in operation. The facility is closed to the public, but you can marvel at it from the trail — and we’ve got the backstory for you.

Don’t call it the Stanford Dish. SRI International, the research institute, leases the land from the university, but any affiliation ends there. It’s simply The Dish — and SRI director of applied technology Jeff Casper and senior research engineer Stephen Muther recently unlocked the gates so we could see the historic radio telescope built in 1961 and learn more.

The 70-ton, 150-foot-wide radio telescope has served an array of purposes over the decades, but initially, it was one of two U.S. telescopes built to unveil information about the Soviet Union’s nuclear testing program. After the Soviet Union launched Sputnik 1 – the first artificial Earth satellite – in 1957, the U.S. became determined to intercept messages Soviets were transmitting to the satellite and detect radar signals they were bouncing off the moon.

When the nuclear test ban treaty was signed in 1963, Casper says, the new question became: “Well now, what do we use this for?” So the Dish took on a new purpose as the Space Race escalated. It supported the Pioneer missions and helped verify the existence of solar wind. It confirmed that while the Soviet Union could claim first arrival to Venus, its satellite lost connection before landing there. During the Apollo program, the Dish helped scientists translate transmissions to determine characteristics of the moon’s surface, Casper says. And it communicated with Voyager I and II on the long voyages past Jupiter, Saturn, Uranus and Neptune.

In recent years, the Dish played a pivotal role in ensuring the U.S. retained access to the L5 radio frequency. That may sound esoteric but, Casper says, it means new generations of smartphones, cars and airplanes will know where they are more accurately.

These days, Muther operates the Dish from a control center situated just below — it looks like a portable classroom. Using publicly accessible data from an app on his phone, he plugs in satellite coordinates, and the Dish rotates, spinning on a large circular track built from decommissioned World War II battleship parts, as it points to the satellite.

The most common request he gets for The Dish these days, he says, is from universities asking for help in contacting small cube satellites, launched by students and no longer responding home. The Dish helps amplify their radio transmissions, enabling them to reconnect.

When it’s not in use, you’ll probably see the Dish sitting in a “bird bath” position, which helps minimize wind impact. It’s also a popular hangout with the local woodpecker population; the Dish routinely collects acorn caches in its metal lattices.

Astonishingly, this isn’t the only longstanding scientific tool hidden among the Stanford hills. Around the corner – and largely hidden from view from the pedestrian trails – is the Wilcox Solar Observatory, a funky 1970s-era geometric tower and the home of a decades-long study now operated by Sadaf Kadir, a friendly, third-year physics grad student who lives onsite with her cat.

Each day, she climbs to the top of the tower, positions the observatory window to just the right angle and lets the sun shine down through mirrors to a spectograph machine that measures the sun’s shifting magnetic field. For years, measurements from the tower were reported directly to the U.S. Navy, she says. The observatory’s findings have also been used to track 11-year solar cycles.

“People assume they know a lot about the sun,” Kadir adds. “But there are a lot of open questions about it.”

Take a hike: Open from sunrise to sunset daily, the paved hiking loop is 3.7 miles, starting from the Stanford Avenue entrance, and 5.3 miles from the Alpine Road entrance (1-7 Piers Lane, Portola Valley). A trip to The Dish is an exercise in hill climbing. Expect to break a sweat as you walk or jog and to have plenty of company on the trail. No pets allowed, but wildlife — squirrels, birds, the occasional coyote or tarantula — abounds. Even without the grandeur of The Dish, the views from the top are spectacular.

Grab a bite: Nearby Fambrini’s Cafe is known for its sandwiches, including The Wanted ($16), filled with avocado, vegan chicken, cheese, barbecue sauce and honey mustard. Open from 9:30 a.m. to 3 p.m. weekdays and 10:30 a.m. to 3 p.m. weekends at 2500 El Camino Real, Suite 105, in Palo Alto; fambriniscafe.com.

The PlanetWalk, Kenwood

The Robert Ferguson Observatory (RFO) in Sonoma County is truly a citizen’s observatory. Named for Bob Ferguson, an amateur Petaluma astronomer who built telescopes for children, it holds the largest publicly accessible telescope in Northern California. Volunteers painstakingly ground its mirror in a Santa Rosa garage over 10 years and chose a soup can for its light baffle.

The nonprofit that operates RFO, the Valley of the Moon Observatory Association, still awards telescopes to kids via its Striking Sparks program. It also holds star-watching parties at the observatory, the building bathed in red light to protect viewers’ night sight, and visitors can peer deep into the twinkling bowels of space. And there have been proposals  at the observatory. One man asked his beloved to look at an asterism (star grouping) in Ursa Minor called the Engagement Ring, saying, “Doesn’t that look like something?” By the time she turned back, he was down on one knee.

The observatory’s grounds in Sugarloaf Ridge State Park are home to a unique citizen-designed hike as well: the PlanetWalk. It’s a 4.5-mile journey that simulates the distances between our sun and the planets, with each step you take representing 1 million miles. You begin in the observatory parking lot at the Sun, where a sign informs that the “Solar System is much larger and emptier than most people realize.” That fact is borne out on the trail – Venus, Earth and Mars pass like a breeze, and by the time you get to Uranus, you might be out of breath and wondering where the frack the next planet is.

“I’m a teacher, and I get really excited about conveying things that are not easy to picture,” says Angelo Parisi, an RFO docent who designed the trail in the 1990s and is now a program director at Lake County’s Taylor Observatory.

“The sizes of the planets and the relative distances between them are numbers we’re not used to dealing with. But when you present somebody with a model like the PlanetWalk, you can understand it a lot. From Pluto, you can look all the way back to the Sun – look back down the canyon and see the barn next to the observatory and get a real sense of how far you’ve come.”

(Pluto hadn’t yet been demoted to dwarf planet when the trail was mapped.)

The hike takes you through a flat valley of brush and moss-furred trees with excellent views of the sun-kissed highlands. It then winds up steeper territory, with hawks circling and fir trees blackened by wildfire, ending near Brushy Peak (elevation 2,243 feet) after a steep scrabble over loose rocks. Interspersed throughout are signs marking the planets you pass – Parisi knew a guy in a metal shop who made them – with facts like “Cold and remote, Neptune is 30 times farther from the Sun than the Earth.”

For the average hiker, getting to the outer limits of the solar system might be demanding. But there’s a way to cheat.