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Pearl Street Planet Walk
Boulder, Colorado
Welcome to the Pearl Street Planet Walk Digital Guide!
Explore each stop as you move from the planets (and Sun) outward, and watch how every few steps in town represents millions of miles in space. Scroll down to the planet you’re visiting for quick facts, bonus stops, and other local highlights. The inner planets are an easy walk west along Pearl Street, while the outer planets are to the east (“the other side of the Sun”)—best reached by bike or car. Join a stargazing event at AstroTours.org to see these actual planets in a big telescope. Enjoy your cosmic stroll!
Google maps:
Walking West (Sun, Mercury, Venus, Earth, Mars, Saturn, {Jupiter} Uranus) HERE
Driving East (Jupiter, Neptune Pluto) HERE
Sun: Mountain Sun Brewing (0 mi)
​Diameter (real): ~865,000 miles
Diameter (this scale): ~68 mm (about 2.7 inches — think a small grapefruit)
Type: G-type main-sequence star (a “yellow dwarf”)
Fun Fact: It’s the powerhouse of our Solar System, providing the light and energy that sustains life on Earth.
Why Here? It’s got “Sun” in the name, plus they’re big on sustainability—just like our actual Sun powers life on Earth! Mountain Sun uses solar panels and local ingredients (like the blackberries in their Blackberry Wheat Ale). Think of that golden ale as liquid sunshine, straight from solar energy to your glass!
Mercury: PosterScene (~0.02 mi from Sun)
Diameter (real): ~3,032 miles
Diameter (this scale): ~0.24 mm (like a tiny poppy seed)
Moons: None
Orbital Period: 88 Earth days
Day Length: 59 Earth days
Fun Fact: Mercury endures extreme temperature swings—scorching on the side facing the Sun and freezing on the dark side.
Why Here? Mercury is a rock that’s blazing hot on one side and freezing cold on the other. PosterScene is all about hot and cool band posters, reflecting that dual nature. Swing by for a look at rare vintage concert art, just steps away from Mountain Sun.
Venus: Stio (~0.04 mi from Sun)
(Bonus Stop: Parking Garage View)
Diameter (real): ~7,520 miles
Diameter (this scale): ~0.59 mm
Moons: None
Orbital Period: 225 Earth days
Day Length: 243 Earth days (it spins backwards!)
Fun Fact: Venus is the hottest planet, thanks to a runaway greenhouse effect in its dense “coat” of an atmosphere.
Why Here? Venus has towering mountains and a thick, heat-trapping “coat” of atmosphere. Stio is all about mountain-inspired apparel that keeps you cozy, too—just on a more comfortable scale than Venus’s 900°F environment! Browse their sustainable, Bluesign®-approved clothing while imagining your own mountain adventures.
Bonus stop: if you want to cross the street there’s a parking garage and you can easily get to the top with the elevator (or stairs if you want to get your steps in) . The top of this parking garage is one of the best views in town. Boulder put in a ban on buildings taller than 55 feet (about 4 stories) in 1971 to preserve the beauty of the mountain views. This parking structure is just under that limit and most of the buildings around it are under that limit too (anything taller was built before 1971) giving you an amazing view of Boulder and the surrounding area.
Earth: Liberty Puzzles Store (~0.05 mi from Sun)
Diameter (real): ~12,700 miles
Diameter (this scale): ~1 mm (a grain of sand)
Moons: 1 (the Moon would be ~0.25 mm and about 30 mm [1.25 inches] away from Earth on this scale)
Orbital Period: 365 days (1 year)
Day Length: 24 hours
Fun Fact: So far, Earth is the only place known to support life—a “mostly harmless” oasis in space.
Why Here? Earth is our home planet—colorful, vibrant, and full of life. Liberty Puzzles is similarly warm and welcoming, with its handcrafted wooden puzzles that connect generations. Drop in to see their whimsical designs, each puzzle piece a nod to how interconnected our world (and Universe!) really is.
(Optional detour: If you’re really feeling adventurous, you can extend your journey to the Liberty Puzzles Factory at 2 miles {biking/driving recommended} that’s Pluto on our scale. More on that below!)
Mars: Into The Wind Kite & Toy Store (~0.08 mi)
Diameter (real): ~6,779 miles
Diameter (this scale): ~0.53 mm
Moons: 2 (Phobos and Deimos)
Orbital Period: ~687 Earth days
Day Length: 24.6 hours (very similar to Earth)
Fun Fact: Known as the Red Planet, Mars has the largest volcano in the Solar System (Olympus Mons).
Why Here? NASA’s helicopter on Mars proved there’s just enough atmosphere to fly a drone—so imagine trying to fly a kite there! Into The Wind celebrates wind, flight, and fun, so it’s the perfect spot for our red planet. Pick up a kite and let Boulder’s breeze do the rest.
Asteroid Belt: Boulder County Courthouse (~0.11–0.16 mi)
Location: Between Mars and Jupiter (~2.2–3.3 AU from the Sun)
Fun Fact: It’s made of countless rocky leftovers from the Solar System’s formation. Some asteroids are hundreds of miles across; most are just specks.
Why Here? The Asteroid Belt is a zone of rocky remnants circling the Sun, and you’ll pass the Boulder County Courthouse (between 13th and 14th Streets) as you navigate “asteroids” of pedestrians and cars. The courthouse’s dramatic history (including a fire) parallels the Solar System’s own turbulent early days. Drop by the Visitor Center to gather more intel on Boulder’s “orbit!”
(bonus stop: Heady Bauer - it’s a really fun vintage shop just of pearl on 13th st, basically across the street from behind the visitor’s center that’s worth stopping by)
Jupiter (stand in): Crossing Broadway
Diameter (real): ~86,881 miles
Diameter (this scale): ~6.8 mm (a small marble)
Moons: 79+ (including the large Galilean moons)
Orbital Period: ~12 Earth years
Day Length: ~9.9 hours (the fastest rotation in the Solar System!)
Fun Fact: Largest planet—its strong gravity helps shield Earth by pulling in or deflecting asteroids and comets.
Why Here? Jupiter is the giant planet that shields Earth from many stray asteroids—just like the crosswalk signals protect pedestrians from oncoming traffic! We’ll symbolically place Jupiter just across Broadway, heading west, though if you want to really visit Jupiter’s stand-in, check out the Phil Lewis Art Gallery further off on the “other side of the Sun” by car/bike (see below).
Saturn: Trident Booksellers & Cafe (~0.48–0.51 mi)
Diameter (real): ~72,367 miles (not counting rings)
Diameter (this scale): ~5.7 mm (small grape)
Moons: 80+ known (plus stunning rings made of ice and rock)
Orbital Period: ~29 Earth years
Day Length: ~10.7 hours
Fun Fact: Named for the ancient god of time (Kronos); it’s a gas giant so light it could theoretically float in water (if you found a bathtub big enough!).
Why Here? Saturn, known to the ancient Greeks as Kronos, symbolizes time—so slow down at Trident with a coffee or tea and a new (or used) book. This halfway point lets you catch your breath, just like Saturn takes its time orbiting the Sun.
Uranus: The People's Crossing (Settlers Park) (~0.98–1.0 mi)
Diameter (real): ~31,518 miles
Diameter (this scale): ~2.5 mm
Moons: 27+
Orbital Period: ~84 Earth years
Day Length: ~17.2 hours
Fun Fact: Tilted on its side by about 98°, so its poles basically face the Sun, giving it very unusual seasons.
Why Here? Uranus is famously “tipped on its side,” encouraging us to see things from a fresh angle. At The People's crossing (formerly known as Settlers Park) , you can hike the Red Rocks Trail for a new perspective on Boulder, flipping your view of the city you just walked much like Uranus flips the usual planetary orientation.
Other side of the sun (Bike/Drive recommended)
As you can see at the people's crossing if you keep going straight you will end up off trail in the mountains (If you stay on the trail and go under the bridge that let’s you safely cross canyon ave you will find yourself on a creek path that can be a good stroll if you want to keep walking up the canyon or you can go with the flow of the river to take a different more scenic way back to the heart of boulder where you started). Because of this the rest of the planets (Jupiter, Neptune, and Pluto) we decided to put on the “other side of the sun” as a reminder that because all of these planets are going around the sun the distances from each other is constantly changing. We have only been going orbit to orbit for these planets, so the actual distances between them are never lined up like this.
Jupiter: Phil Lewis Art Gallery (~.28 mi from the sun)
Diameter (real): ~86,881 miles
Diameter (this scale): ~6.8 mm (a small marble)
Moons: 79+ (including the large Galilean moons)
Orbital Period: ~12 Earth years
Day Length: ~9.9 hours (the fastest rotation in the Solar System!)
Fun Fact: Largest planet—its strong gravity helps shield Earth by pulling in or deflecting asteroids and comets.
Why Here? Phil Lewis uses colourful wavy lines just like the colour bands of Jupiter. Also Jupiter is considered a solar system within the solar system as it has lots of moons that are all interesting planetarily. When you get sucked into Phil Lewis’s art you will be in a universe within our own universe.
Neptune: Junkyard Social Club (~1.50–1.60 mi)
Diameter (real): ~30,599 miles
Diameter (this scale): ~2.4 mm
Moons: 14+ (Triton is the largest)
Orbital Period: ~165 Earth years
Day Length: ~16 hours
Fun Fact: Farthest major planet from the Sun, with supersonic winds and a deep blue color caused by methane in its atmosphere.
Why Here? Neptune is mysterious, blue, and full of surprises—just like the playful, imaginative spirit at Junkyard Social Club! This artful indoor/outdoor space (with coffee, events, and kid-friendly activities) feels as eclectic as exploring the farthest reaches of our planetary neighborhood.
Pluto: Liberty Puzzles Factory (~2.0 mi)
Diameter (real): ~1,477 miles
Diameter (this scale): ~0.12 mm (barely bigger than a speck of dust)
Moons: 5 (Charon is almost half Pluto’s size)
Orbital Period: ~248 Earth years
Day Length: ~153 hours (about 6.4 Earth days)
Fun Fact: Though reclassified as a dwarf planet, Pluto has a complex geology—icy mountains, possible subsurface ocean, and even “cryovolcanoes.”
Why Here? Tiny, distant Pluto holds clues to our Solar System’s history—just as Liberty Puzzles’ collection of vintage wooden puzzles speaks to a time-honored tradition. If you’re up for the drive (or a good bike ride or a long walk!), head about 2 miles from our “Sun” to see lasers carving intricate wooden puzzles. This is where the journey really ends, at the far frontier of our Pearl Street Planet Walk scale!
Other Boulder Highlights
When you’re done exploring Pearl Street’s “solar system,” there’s still plenty to see around Boulder:
Boulder Dushanbe Teahouse: A hand-crafted Tajikistan treasure with delicious international teas and cuisine.
NCAR (National Center for Atmospheric Research): Fascinating exhibits and gorgeous trails; learn about our planet’s weather and climate.
Celestial Seasonings Tea Factory: Take a tour to see how famous teas are blended and sip free samples.
Sunrise Amphitheater: Catch breathtaking sunrises (or sunsets) from this iconic lookout on Flagstaff Mountain.
Boulder Falls: Drive up the canyon for a short walk to a lovely waterfall—perfect for a quick nature break.
Mork & Mindy House: Fans of the classic sitcom can snap a photo at this quirky TV landmark.
AstroTours.org: Want to see the real planets in a telescope? Visit AstroTours for stargazing events and an up-close look at celestial wonders.
