The Lowdown Guide — Flagstaff Dark Sky Stargazing Tour GPS Audio Tour Transcript --- STOP 1: Lowell Observatory — Where Pluto Was Discovered Welcome to your Flagstaff Dark Sky Stargazing Tour. You're standing at Lowell Observatory, perched on Mars Hill at 7,250 feet above sea level — and you're about to spend an evening under some of the darkest, most protected skies of any city in America. Flagstaff received its dark-sky designation in 2001 — the world's first. The awarding body is the organization now called DarkSky International, which at the time was named the International Dark-Sky Association; in its own words, "Flagstaff is the world's first International Dark Sky Place, receiving its designation in 2001." The city's lighting code names low-pressure sodium lamps and narrow-spectrum amber LEDs as the preferred light sources, requires fixtures to be shielded, and caps the total lumens a property may put out per acre. That work goes back to 1958, when Flagstaff enacted what DarkSky International calls "the world's first outdoor lighting ordinance." [SOURCE: https://darksky.org/places/flagstaff-arizona-dark-sky-community/] This observatory is the reason it all started. Percival Lowell — Boston Brahmin, mathematician, and committed believer in life on Mars — founded this institution in 1894. He chose Flagstaff for its altitude, dry climate, and the extraordinary transparency of the atmosphere above the Colorado Plateau. Lowell spent years mapping what he believed were irrigation canals on Mars. He was wrong about that. But he was right about something else: he predicted, from what he read as irregularities in the orbits of the outer planets, that a ninth planet existed beyond Neptune. Lowell Observatory built the instrument that would eventually find it — a 13-inch astrograph, built in 1928 and 1929 expressly to complete the search for what he called Planet X. Lowell died in 1916 without finding it. Fourteen years later, on February 18, 1930, observatory assistant Clyde Tombaugh — working at this very observatory, at the 13-inch Lawrence Lowell Astrograph in the dome just above you — was reviewing a set of glass photographic negatives of the same patch of sky, taken days apart, when he caught a tiny point of light that had moved between them. He had found Pluto. [SOURCE: https://lowell.edu/discover/history/clyde-tombaugh-and-the-discovery-of-pluto/] Tonight, that history matters to your stargazing. Lowell's legacy is the reason Flagstaff treats its skies as a public resource worth protecting. You'll hear the phrase limiting magnitude several times tonight — it means the faintest star your naked eye can pick out, and it's the standard shorthand for how dark a site is. On John Bortle's published scale, a rural-to-suburban transition sky tops out at magnitude 6.1 to 6.5 and a genuinely rural sky runs 6.6 to 7.0. Here on Mars Hill you are still inside the city, so set your expectations at the lower end of that range — and it will still beat almost any American suburb. Before we move on: if Lowell Observatory is offering evening programs tonight, strongly consider booking one. Lowell lists visiting hours running to 11:00 pm and notes that telescope viewing usually starts around sunset — but admission prices and program times change, so check lowell.edu/visit for tonight rather than trusting a number from a recording. Their 24-inch Clark Refractor, built in 1896 and still in active use, is one of the most extraordinary things you can look through in Arizona. One practical note before we begin: go ahead and turn off your phone's flashlight and switch to a red flashlight app if you have one. Your eyes need a good 20 to 30 minutes to dark-adapt — the pupil dilates and the rod cells in your retina shift to their low-light sensitivity mode. Any white light resets that process completely. Astronomers use red light because long-wavelength red photons don't trigger the same chemical reset. Protect your dark adaptation from this moment forward and you'll see ten times more tonight. [SOURCE: https://lowell.edu/visit/] We'll be driving north and east of town over the next several hours. Recommended apps for tonight: Stellarium (free, Android and iOS) or Sky Map. Set them to red-light mode. Now the part that matters more than any of the astronomy, because this is a night drive through rural northern Arizona at 7,000 feet and above. Elk. The Arizona Department of Transportation reports 1,830 vehicle collisions with animals statewide in 2022, causing four deaths and 280 injuries, and notes that an average bull elk weighs about 900 pounds and a cow around 500. ADOT and Arizona Game and Fish say: slow down, because lower speed buys reaction time; stay alert, especially at dusk and dawn; scan ahead for movement along the roadsides. If an animal steps out, normally do NOT swerve — stay in your lane and brake firmly. Cold. Even in July, nights up here fall into the 40s and 50s, and in winter into the teens and single digits; you will be standing still rather than generating heat, so bring more layers than you think you need, plus a hat and gloves. Roads. Coconino National Forest gates many forest roads through the winter — in their words, "to reduce the risk of stranded forest visitors" — so check the Forest Roads Status page before you commit to any dirt road tonight, and if you find a closed gate, that is your answer. Fuel up before you leave town, tell someone your route, carry water, and expect stretches with no cell service. Let's begin. [SOURCE: https://azdot.gov/adot-blog/driving-rural-areas-pay-attention-wildlife-near-highways] [SOURCE: https://www.fs.usda.gov/r03/coconino/conditions/forest-roads-status] --- STOP 2: Mars Hill Pull-Off — Astronomical Twilight & Dark Adaptation You're just below Lowell Observatory now, at a pull-off on the Mars Hill road heading back down toward town. Use a marked pull-off with room to get completely off the pavement — if there isn't one where you are, keep driving until there is, and never stop in a travel lane. What you want here is an open view of the western horizon, and about 30 to 45 minutes. The sun has set, but the sky isn't dark yet. What you're watching now is the transition through three distinct phases of twilight that astronomers actually have official names for. Civil twilight, the first phase, ends when the sun drops 6 degrees below the horizon — that's when you can no longer read outside without artificial light. Nautical twilight ends at 12 degrees below the horizon — historically when sailors could no longer distinguish the horizon from the sea. But the phase that matters for stargazing is the third one: astronomical twilight, which ends when the sun reaches 18 degrees below the horizon and the sky reaches its true nighttime darkness. [SOURCE: https://www.weather.gov/lmk/twilight-types] Flagstaff sits at about 35 degrees north latitude, so full astronomical darkness arrives somewhere between roughly one and two hours after sunset depending on the season — later in summer, sooner in winter. Don't plan off a number from a recording: the U.S. Naval Observatory publishes exact sunrise, sunset and twilight times for any date and location, and that is the figure to use. For calibration, USNO gives Flagstaff a June 21st sunset of 7:44 pm and a December 21st sunset of 5:18 pm — Mountain Standard Time, because Arizona does not observe daylight saving time. Until full darkness, there's still enough scattered sunlight in the upper atmosphere to wash out faint objects near the horizon. The planets and the brightest stars will appear first — you may already see Venus or Jupiter if they're above the horizon tonight. The Milky Way's core becomes visible only after full astronomical darkness. Now turn your back on the sunset and watch the EASTERN horizon — this is where an earlier version of this tour had it backwards, so listen closely. The dark blue-grey band climbing up from the eastern skyline is the shadow of the Earth itself, cast opposite the sun. The pink-to-rose band sitting directly on top of that dark band is the Belt of Venus, also called the antitwilight arch: sunlight reddened by a long path through the atmosphere and backscattered toward you. So the two are stacked — dark shadow below, pink Belt above — and the boundary between them is the top edge of Earth's shadow. Most people who photograph it never know which band is which. Now you do. [SOURCE: https://aa.usno.navy.mil/data/RS_OneDay] While you wait for true darkness, a brief word about the Bortle scale — you'll hear it several times tonight. John Bortle, an amateur astronomer, developed this 9-class scale in 2001 to standardize sky quality descriptions. Bortle 1 is the darkest sky on Earth, found only in remote deserts and high-altitude wilderness. Bortle 9 is the inner city, where only the moon, a handful of bright stars, and planets are visible. Most American suburbs sit at Bortle 7 or 8. One warning about Bortle numbers before you hear any more of them. You will find specific class ratings quoted for specific pullouts all over the internet, and almost none of them come from a published measurement — including for the stops on this tour. Treat any site-specific class you hear, from me or anyone else, as opinion. What IS documented is the scale itself. Bortle's Class 4, the rural-suburban transition, is where "the Milky Way well above the horizon is still impressive but lacks all but the most obvious structure," with a naked-eye limit of magnitude 6.1 to 6.5. Class 3, a rural sky, is where the Milky Way "still appears complex," globular clusters become distinct naked-eye objects, and the zodiacal light is "striking in spring and autumn" — naked-eye limit 6.6 to 7.0. And file this one away, because it gets claimed for places that don't earn it: the Milky Way casting obvious shadows on the ground is a Bortle Class 1 phenomenon, the darkest class on the scale. Do not expect it at any stop tonight. [SOURCE: https://skyandtelescope.org/astronomy-resources/light-pollution-and-astronomy-the-bortle-dark-sky-scale/] Keep your eyes on the west. In the next few minutes, the first stars will begin punching through. That's your signal to drive north. Stay in red-light mode. --- STOP 3: Buffalo Park — Naked-Eye Observing & the Milky Way Core You're at Buffalo Park, a broad city open space on McMillan Mesa on the north side of Flagstaff. USGS elevation data puts this spot at about 7,000 feet. You'll see the park's acreage quoted several different ways online; the City of Flagstaff is the authority on that — and on the gate hours, which is the practical point: this is a city park with a posted closing time. Read the sign at the entrance and don't stay past it. The city's light dome is toward town, but north and east you have a genuinely darker horizon — and that's where the good stuff lives tonight. This is an in-town site, so expect an in-town sky: a real light dome toward the city, thousands of naked-eye stars, and the Milky Way overhead as a distinct, cloud-like band rather than the textured river you'll see later tonight. No measured darkness rating has been published for this specific field, so don't trust one — including from me. If this is your first time out of a suburb, your reaction in the next few minutes is still going to surprise you. Let's orient. The Milky Way is the disk of our own galaxy seen edge-on from inside it. We live roughly 26,000 light-years from the galactic center, well out in the disk on the Orion Arm — a minor spiral arm between two major ones. When you look toward Sagittarius in the southern sky, you're looking toward the galactic core, where star density is highest and the Milky Way appears brightest and most textured. When you look toward Perseus and Cassiopeia in the north, you're looking outward toward the galaxy's edge. [SOURCE: https://science.nasa.gov/skywatching/] Depending on the season, different sections of the Milky Way dominate the sky. From June through September, the galactic core rises in the south — the richest, most photogenic portion, with dark dust lanes and nebulae visible to the naked eye. In winter, Orion rises in the east with its nebula (M42) visible as a fuzzy patch without any optical aid at this sky quality. Right now, find the three bright stars of the Summer Triangle — Vega, Deneb, and Altair — if they're up. Vega, the brightest of the three, is almost directly overhead from Flagstaff in midsummer. The Milky Way runs directly through the triangle, and from this park, you should be able to trace it as a continuous band from the southern horizon all the way to the north. [SOURCE: https://science.nasa.gov/skywatching/] Practical note for this stop: lie on your back on the grass. Seriously. Neck strain is one of the most overlooked challenges of amateur astronomy. A reclining camp chair or a blanket on the ground transforms naked-eye observing. Give yourself 10 full minutes of uninterrupted sky gazing — no phone, no white lights — and let your eyes finish dark-adapting. The sky will literally get darker as you watch. You may have read that the Milky Way casts a visible shadow here. It does not. On Bortle's scale, the Scorpius and Sagittarius regions of the Milky Way casting obvious diffuse shadows on the ground is a Class 1 sky — the darkest class there is, found in remote wilderness, not on the edge of a city. What you CAN do from this field is trace the band continuously across the sky and pick out its brighter and darker stretches. That's plenty for a ten-minute drive from downtown. Before we leave: if you want a structured guided night sky experience with a telescope, Lowell Observatory's on-campus programs include access to multiple telescopes and are led by trained astronomers. Book at lowell.edu/visit — evenings typically sell out on weekends during peak season. [SOURCE: https://lowell.edu/visit/] --- STOP 4: Schultz Pass Road (FR 420) — Above the Light Dome You're on Schultz Pass Road — Forest Road 420 — in the Coconino National Forest north of Flagstaff. The Forest Service gives the approach exactly: drive north from Flagstaff about two miles on U.S. Highway 180, and just beyond the Museum of Northern Arizona, turn EAST onto Schultz Pass Road. Note that this is a different road from Hart Prairie Road on the west flank of the Peaks; an earlier version of this tour ran the two together, and they are not the same place. On elevation, the Forest Service lists this site at 7,159 feet and USGS puts the terrain along this stretch nearer 7,500 — either way, well short of the 8,200 feet you may have heard, and still high enough to put part of the city's light dome below you. The openings along the road give you real horizon in several directions. Two hard practical facts about this road before you settle in. The Forest Service says FR 420 "is graveled but suitable for passenger cars in most weather" and that "it is closed in winter when snowfall warrants" — every winter, Coconino National Forest gates a long list of forest roads. Check the Forest Roads Status page for FR 420 under the Flagstaff Ranger District before you drive it, and if you meet a closed gate, turn around. The Forest Service also notes there's "a good chance you'll see some of the resident elk, mule deer or other animals" along this drive. After dark, on gravel, that is a hazard rather than a bonus — keep your speed down. [SOURCE: https://www.fs.usda.gov/r03/coconino/recreation/schultz-pass-road-scenic-drive] [SOURCE: https://www.fs.usda.gov/r03/coconino/conditions/forest-roads-status] This is a meaningful step up from the city parks below, though I won't hand you a Bortle class for it — no one has published a measurement for this stretch of road. What matters is that faint extended objects start rewarding careful naked-eye work here. The Andromeda Galaxy, M31, is the one to try: NASA puts it about 2.5 million light-years away at apparent magnitude 3.1 and notes it "can be seen with the naked eye, even in areas with moderate light pollution." Look for it in the constellation Andromeda — not Perseus, though Perseus is the neighbor most people star-hop from — as an elongated smudge on dark autumn nights. You'll also hear M31 called the farthest thing the naked eye can see. It's a nice line, but it isn't settled: M33 in Triangulum is farther and is a documented naked-eye target under good skies. [SOURCE: https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-31/] Look toward the northwest. You're in the direction of the Milky Way's outer arm — the sky here has lower star density than toward the galactic center in the south, but the dark dust clouds of the Cygnus Rift become more apparent. Those dark patches in the Milky Way aren't empty space — they're dense clouds of interstellar gas and dust absorbing the light of stars behind them. Some of the largest stellar nurseries in the galaxy are hidden inside them. The meadow environment here serves a dual purpose. The open, relatively flat terrain means you're not hemmed in by tree lines, so you can observe objects at low elevation — planets, comets, and faint naked-eye objects within 15-20 degrees of the horizon are accessible. Low-altitude objects suffer from more atmospheric extinction (the atmosphere is thicker at shallow angles), so a prairie site like this partly compensates by removing the tree-line obstruction. [SOURCE: https://science.nasa.gov/skywatching/] If you're here in late summer or early fall, watch the southeastern horizon carefully over the next hour. Sagittarius and Scorpius — the two constellations richest in deep-sky objects — arc low across the southern sky from Flagstaff's latitude. Messier 24, the Small Sagittarius Star Cloud, is a dense patch of Milky Way stars roughly 10,000 light-years away that appears as an intensely bright, milky oval to the naked eye. Don't confuse it with the Great Sagittarius Star Cloud nearby — they are two different patches, and the names get swapped constantly. No binoculars required — just patience and a low, dark southern horizon. [SOURCE: https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-24/] Listen as well as look. This is working national forest on the flank of the San Francisco Peaks, and it is genuinely alive after dark — the Forest Service notes resident elk and mule deer through here, and on summer nights you'll hear insect-hunting birds working the openings. Whatever you hear, keep your distance and don't go walking into the trees after it in the dark. If the seeing (atmospheric steadiness) is good tonight — you can judge this by how much the stars are twinkling near the horizon — then even small binoculars will open up a different universe at this site. The Pleiades cluster becomes dozens of stars instead of seven. Jupiter resolves its four bright Galilean moons. This is where moderate optical aid starts to pay off. Next, we head back out to US 180, around through town, and north on US 89 toward the volcanic landscape. Watch for elk the entire way. --- STOP 5: Sunset Crater Volcano National Monument — Milky Way Over Lava You've arrived at Sunset Crater Volcano National Monument. The Park Service directions are exact: take U.S. 89 north from Flagstaff for 12 miles, then turn right onto the Sunset Crater–Wupatki Loop Road and continue two miles to the visitor center — about a 30-minute drive from town. And here is a correction to something this tour used to tell people: the monument is NOT closed after dark. In the Park Service's own words, "the scenic drive and all trails are open year round, day and night, unless extreme snowfall or other weather events make them impassable." You are allowed to be here tonight. What you are not allowed to do is stop wherever you please. The Park Service is blunt: "Park roads are narrow and winding with soft shoulders. Stop only at designated pullouts, never in the road." Stay on designated trails as well — everything out here is protected by federal law, with substantial fines for disturbance. And heed their GPS warning: navigation apps regularly route visitors onto rough dirt roads out here, and unless you are in a high-clearance four-wheel-drive vehicle you should avoid any unfamiliar unpaved road. [SOURCE: https://www.nps.gov/sucr/planyourvisit/hours.htm] [SOURCE: https://www.nps.gov/sucr/planyourvisit/directions.htm] Sunset Crater is the youngest volcano in the San Francisco Volcanic Field. The Park Service dates the eruption to "around the year 1085" and says it "displaced area residents, buried homes, and radically altered the landscape below O'Leary Peak." Thirteen federally recognized Tribes are traditionally associated with these lands, and the descendants of the people who lived through that eruption are here today — the Park Service notes that stories of it survive to the present. You will also hear that the ash enriched the soil and drew a population boom to the Wupatki basin afterward. That is a long-standing archaeological interpretation rather than a settled fact, so hold it loosely; the Park Service's own archeology pages are where to follow it up. [SOURCE: https://www.nps.gov/sucr/learn/historyculture/index.htm] The cinder fields here create an almost lunar landscape — irregular black and dark red volcanic rock stretching to the horizon in every direction. At night, this matters astronomically. Dark terrain absorbs rather than reflects light, which means less skyglow bounces upward from the ground around you. The sky above a lava field is measurably darker than the sky above a white salt flat or a reflective city surface. I won't give you a decimal Bortle rating here, because there is no such thing — the Bortle scale runs in whole classes from 1 to 9, and no measured value has been published for this spot anyway. What you can confirm with your own eyes: the horizon is largely free of major obstructions, the San Francisco Peaks loom to the southwest, and that is also the direction of Flagstaff's light dome. North and east is your cleanest sky from here. [SOURCE: https://skyandtelescope.org/astronomy-resources/light-pollution-and-astronomy-the-bortle-dark-sky-scale/] This is an excellent stop for meteor observation. The flat, open terrain lets you watch large swaths of sky simultaneously, which is exactly what meteor watching requires. The two strongest annual showers are the Perseids in mid-August and the Geminids in mid-December. Peak nights shift from year to year, so get this year's dates and predicted rates from the American Meteor Society's shower calendar rather than from a fixed number in a recording. And understand what a published rate means: it is a zenithal hourly rate — the count one observer would get under a perfect sky with the radiant directly overhead. Your real-world count will be lower, sometimes much lower. The Perseids are the comfortable one; the Geminids are usually the richer shower but demand serious winter gear at this altitude. [SOURCE: https://www.amsmeteors.org/meteor-showers/meteor-shower-calendar/] If you have binoculars, turn them toward the Double Cluster in Perseus, visible to the naked eye as a fuzzy spot in the northeastern sky from October through February. In binoculars, it resolves into two distinct star clusters — NGC 869 and NGC 884 — each containing hundreds of stars, roughly 7,500 light-years away. Considered one of the finest binocular objects in the sky. At this stop, also watch the ground. Snakes are part of the wildlife out here, and Park Service guidance covers all of it in one line: never feed or approach any animal, "whether it's a cute squirrel or a colorful snake" — and if an animal changes its behavior because you're there, you are too close. Watch your footing as well; the Park Service warns that rocks out here are "sharp, brittle and unstable" and that cinders can be slippery, and falling on either is an unpleasant experience. Stay on designated surfaces, and put your red light on the ground before you put a hand anywhere in the dark. [SOURCE: https://www.nps.gov/wupa/planyourvisit/safety.htm] We continue north to Wupatki, where the skies get noticeably darker. --- STOP 6: Wupatki National Monument — Exceptionally Dark Skies, Ancient Ground You've driven about 33 miles from Flagstaff — 12 miles north on US 89, then 21 more from that junction to the Wupatki Visitor Center, which the Park Service calls a 45-to-60-minute drive — and the sky above you has shifted into a different category. The Park Service says it plainly: "Wupatki National Monument features exceptionally dark night skies and hosts numerous star parties each year." Read this next part before you get out of the car, because it decides where you can legally stand tonight. At Wupatki, "the park road is open 24/7, 365 days a year," but "trails and pueblos are open year-round, from sunrise to sunset." So you may drive this road after dark and observe from designated pullouts. You may NOT walk out to the pueblos at night — an earlier version of this tour implied you could, and that was wrong. The ruins close at sunset, everything here is protected by federal law with substantial fines for disturbance, and the Park Service asks visitors to stay on designated trails and to "stop only at designated pullouts, never in the road." Observe from the road corridor with the pueblos as a silhouette on the horizon, and come back in daylight to walk among them. [SOURCE: https://www.nps.gov/wupa/planyourvisit/hours.htm] [SOURCE: https://www.nps.gov/wupa/planyourvisit/safety.htm] [SOURCE: https://www.nps.gov/wupa/planyourvisit/directions.htm] Bortle's Class 3 — a rural sky — is defined by a naked-eye limiting magnitude of 6.6 to 7.0, by globular clusters such as M4, M5, M15 and M22 standing out as distinct naked-eye objects, and by a zodiacal light that is "striking in spring and autumn." That zodiacal light is a faint pyramid of glow rising from the western horizon along the ecliptic after evening twilight, and from the east before dawn — sunlight scattered off interplanetary dust. Whether tonight's sky here reaches that class depends on the moon, the season and the air, and I'm not going to assert a class for you. Go look, and judge it against the published scale yourself. What is fair to say is that a great many people have never seen the zodiacal light at all. [SOURCE: https://skyandtelescope.org/astronomy-resources/light-pollution-and-astronomy-the-bortle-dark-sky-scale/] Out there in the dark is Wupatki Pueblo, the monument's namesake, which the Park Service says "preserves 104 rooms, a ballcourt, and a natural blowhole feature." The builders were, in the Park Service's current wording, "the ancestors of contemporary Pueblo communities" — you will see the older label Sinagua used widely, but thirteen Tribes officially recognize this area as culturally significant today, and that is the framing the Park Service now uses. The timeline, from the Park Service: people have lived here for over 13,000 years, and "by the early 1100s there were around 2,000 people within 50 miles of Wupatki Pueblo," communicating, cooperating and trading "until the mid-1200s when an extended drought and strong cultural ideas in migration led people to move into other areas." You'll also hear confident claims about solstice and equinox alignments engineered into sites in this region. Archaeoastronomical work exists; how much of it is established is a question for the Park Service and the descendant communities, not for a tour recording. [SOURCE: https://www.nps.gov/wupa/index.htm] [SOURCE: https://www.nps.gov/wupa/learn/historyculture/people.htm] From the road here you have a nearly unbroken sky view: the terrain around Wupatki is high desert scrubland at roughly 4,850 feet by USGS elevation data — well below Flagstaff — so treeline obstruction is minimal and the horizon is nearly fully open in all directions. The lower elevation does add atmospheric path length for objects near the horizon. Rather than rank this against every other site in Arizona, take the Park Service's own assessment: exceptionally dark night skies, dark enough that they run star parties here. If you're visiting between April and October, find the galactic core in the southern sky — the thick, textured band of the Milky Way running from Sagittarius toward Scorpius. In binoculars, this region dissolves into layers: countless unresolved stars in the background, dark rifts from dust clouds in the midground, and resolved star clusters and nebulae in the foreground. The Lagoon Nebula (M8) is visible to the naked eye as a distinct misty patch next to a star cluster. The Omega Nebula (M17) is similar. Both are stellar nurseries a few thousand light-years away — published distances for the two differ, so treat "a few thousand light-years" as the honest figure rather than a single round number. [SOURCE: https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-8/] If you want a genuinely hard target, try Corona Australis, the Southern Crown — a small arc of faint stars below Sagittarius. From this latitude it never climbs far above the southern horizon, so it needs summer timing, a clean southern skyline and a dark night. Don't try to find it by counting stars off a recording; put it into your sky app, let the app point you, and see whether the horizon here gives it to you. Small victories matter in astronomy. The combination of this landscape and the sky above it is, for a lot of people, the whole reason to drive north of Flagstaff at night. Take your time with it — and take it from the road corridor and the designated pullouts, not from among the ruins. The drive back to Flagstaff is about 33 miles and takes the better part of an hour on a dark two-lane. There's no rush, and no reason to hurry it in the dark. One correction worth carrying home if you plan a future overnight here. A planet at opposition is not a pre-dawn object. Opposition means the planet sits opposite the sun as seen from Earth, so it rises around sunset, stands highest in the south near local midnight, and sets around sunrise — it is up all night, and the best view is near the middle of the night. If you want a room with a sky view, an unobstructed horizon and a high floor matter far more than which compass direction the window faces. --- STOP 7: Anderson Mesa — The Darkest Accessible Sky Near Flagstaff Anderson Mesa lies about 15 miles southeast of Flagstaff, and USGS elevation data puts the ground here right around 7,100 feet. This high, flat tableland is Lowell Observatory's dark-sky research site — home to the 42-inch Hall Telescope, which Lowell describes as "a workhorse telescope at Lowell's Anderson Mesa dark-sky site for more than half a century." LONEOS, the Lowell Observatory Near-Earth-Object Search, ran its automated Schmidt telescope here until 2008; across about ten years of operation it discovered 289 near-Earth asteroids and 42 comets from some 450,000 exposures. The mesa also hosts the Navy Precision Optical Interferometer. Get the name right, because the old one is still quoted everywhere: it began life as the Navy PROTOTYPE Optical Interferometer and that name is retired. It is operated by Lowell Observatory in partnership with the Naval Research Laboratory and the U.S. Naval Observatory — not by the Naval Observatory alone. And one more local claim worth correcting: the Naval Observatory Flagstaff Station is its own separate facility, not the installation on this mesa. That brings up the etiquette that matters most here. These are ACTIVE research instruments on observatory property. Do not drive in past the gates, and keep white light — headlights, phone screens, flashlights — pointed away from the domes. Park only on public road pullouts, well clear of the entrance. [SOURCE: https://lowell.edu/research/research-telescopes/anderson-mesa/] [SOURCE: https://asteroid.lowell.edu/loneos/] [SOURCE: https://epqs.nationalmap.gov/v1/json?x=-111.6647&y=35.2028&units=Feet&wkid=4326] Anderson Mesa has a well-earned local reputation as the darkest sky within an easy drive of Flagstaff, and the fact that professional astronomers sited a research observatory here is the strongest evidence you'll get for it. Beyond that I won't quote you a class rating or a limiting magnitude — no measured figure has been published for the public pullouts, and the numbers circulating online are estimates. Position matters more than any number anyway: get as far from the Flagstaff side as you can and put terrain between you and the city glow. People come up here hunting the gegenschein — a faint oval glow in the sky exactly opposite the sun, sunlight backscattered off interplanetary dust. Be realistic about your odds. On Bortle's scale, the gegenschein is listed under Class 1, the excellent dark-sky site, alongside a naked-eye limiting magnitude of 7.6 to 8.0. That is darker than anything on tonight's route. It was first described in the mid-1800s by the astronomer Theodor Brorsen — you'll see his nationality stated confidently and inconsistently in popular sources, so I'll leave that one to the historians rather than repeat a guess. The honest summary: most observers never see the gegenschein. Treat a sighting tonight as a long shot, not an expectation. [SOURCE: https://skyandtelescope.org/astronomy-resources/light-pollution-and-astronomy-the-bortle-dark-sky-scale/] The Anderson Mesa site also benefits from its terrain. The mesa is elevated above the surrounding valley floor, which means the coldest air — which produces the worst seeing conditions — drains away downslope rather than pooling around you. Thermal stability is a significant factor in image quality through telescopes, but it also affects the steadiness of stars to the naked eye. Stable air means stars twinkle less. That reduced scintillation makes faint objects easier to hold with averted vision — the technique of looking slightly to the side of a faint object so its light falls on the more sensitive rod cells rather than the cone-dense fovea at the center of your vision. For your final observing session tonight, consider a deliberate scan of the constellation Virgo if it's above the horizon. In a modest telescope, the Virgo Cluster begins to reveal itself as a scattered field of small, fuzzy ellipticals. Three things this tour used to get wrong here, now fixed. It is a galaxy CLUSTER, not a supercluster — the Virgo Supercluster is a far larger structure that contains it. NASA describes the Virgo cluster as containing "some 2,000 galaxies," not thirteen hundred. And its dominant member, M87, sits about 54 million light-years away, not sixty-five. M87 is the galaxy whose supermassive black hole became the first ever directly imaged, announced by the Event Horizon Telescope collaboration on April 10, 2019. [SOURCE: https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-87/] Before you pack up for the evening: look one final time at the full sky and try to let your brain absorb what you've been seeing tonight. That light entered your eyes after traveling for thousands, millions, and in some cases billions of years. The Andromeda Galaxy, visible to the naked eye as a faint smudge, emitted that light 2.5 million years ago — before Homo sapiens existed. The universe is almost incomprehensibly old and large, and you spent an evening looking directly at it from the place that wrote the world's first outdoor lighting ordinance in 1958 and became the world's first International Dark Sky Place in 2001. Flagstaff's commitment to dark sky preservation is a living experiment in whether a modern city and a wild night sky can coexist. So far, it's working. That's the real reason you came here. Thank you for touring with The Lowdown Guide. Now drive home carefully, and do it by the state's own guidance rather than by folklore. The Arizona Department of Transportation and Arizona Game and Fish say: slow down, because lower speed buys reaction time; stay alert, particularly at dusk and dawn; scan ahead and watch for movement along the roadsides; obey wildlife warning signs. If an animal steps out, normally do NOT swerve — stay in your lane and brake firmly. Only consider swerving for a very large animal when there is no oncoming traffic and the shoulder is safe on either side. And ignore the old advice about running low beams out here: with no oncoming traffic, high beams pick up eyeshine far sooner — just dip them the moment you see another vehicle. An average bull elk runs about 900 pounds. Give yourself the room. [SOURCE: https://azdot.gov/adot-blog/driving-rural-areas-pay-attention-wildlife-near-highways] --- Generated for WCAG 2.1 AA accessibility compliance.