BRUNEAU — Let your eyes adjust to the darkness. With the help of a few dim red lights, find the movable doorway of the Bruneau Dunes Observatory and step inside.
There, dots of faint red light on the floor and the round walls mimic stars and constellations — providing just enough illumination for you to find the line of dark figures waiting for their turns at the eyepiece of a 25-inch telescope.
Your reward: perhaps the cloud belts and the four Galilean moons of Jupiter. Or the Cassini division between Saturn’s two most prominent rings. Or the big spiral arms of the Whirlpool Galaxy, 35 million light-years away, appearing to gobble its companion galaxy.
It’s a great way to spend a summer night.
And it’s a singular experience in a southern Idaho state park. In fact, the 25-inch Newtonian reflector telescope at Bruneau Dunes State Park is Idaho’s largest public telescope, programmed with the ability to find and track tens of thousands of objects. And it’s in an ideal spot, where the sky is dark enough to see the Milky Way stretch from horizon to horizon.
When the telescope points at M13 — a globular cluster of about 300,000 stars in the constellation Hercules — it fills the whole eyepiece.
“This is as big as it gets looking for fun,” said telescope operator Kirk Long, who studies astrophysics at Boise State University and is an intern for astrophysicist Neil deGrasse Tyson’s “StarTalk” radio show.
And it’s fun that anyone can enjoy. On Friday and Saturday nights, Bruneau Dunes employees and volunteers point the big telescope and a collection of smaller ones at celestial targets such as star clusters, nebulae and supernova remnants.
At the height of summer, the observatory averages 100 to 150 visitors each night; last season’s record was 277. But when the crowd thins out later in the night, you won’t have to wait in line long to see the distinct red of Antares in the constellation Scorpius, or the striking color contrast of the Albireo double star — a brighter yellow star, itself a binary system, and its fainter blue companion.
“If you came back in a few months,” telescope operator Greg Harman said July 21, “we’d have a whole different set of objects to view.”
The observatory staff programs alarms to ensure visitors can look in the right direction at the right time to see brief, bright Iridium flares, made when communication satellite antennas reflect sunlight directly onto Earth’s surface.
Just another feature of the night sky that you might otherwise overlook.
Take time during your visit for a diversion that has nothing to do with stars, but everything to do with the dark: glowing scorpions.
Yes, the fluorescing chemicals in their skin make scorpions glow a vibrant blue-green at night when they’re caught in the beam of an ultraviolet light. If you get a good look, it’s a sight you won’t quickly forget.
In the warmest months, Bruneau Dunes takes advantage of this desert phenomenon. About midway through the telescope viewing session, an interpreter leads anyone who’s interested on a short walk near the observatory. He wields a big UV light and walks quickly, sweeping the beam across the ground to look for scorpions. When he finds one, he lets everyone file past for a look.
From the Magic Valley, drive west on Interstate 84 to the Hammett exit. From there, take Idaho 78 south then west to the park entrance, 14 miles from Hammett.
A daily $5 motor vehicle entry fee is required year-round at Bruneau Dunes — unless you have the $10 annual Idaho State Parks Passport.
In addition, the observatory viewing fee is $5 per person, $20 for a family, $3 for seniors 62 and older, free for children 5 and younger and $3 for any student 6-17 who’s on a school field trip. (You’ll get a glow-in-the-dark sticker to show you paid the fee; later in the night, you and other visitors will look something like a crowd of caffeinated fireflies.)
Think ahead, because the observatory accepts only cash or check; if you need to use a credit card, you can purchase tickets in advance during office hours at the park’s visitor center.
Bruneau Dunes Observatory is open to the public on Friday and Saturday evenings only, from late March through mid-October.
In July, observatory tours and solar viewing — through a specially adapted solar telescope — begin at 7:30 p.m.; in August through October they start at 6:30 p.m. Expect to see sunspots and solar textures, prominences and filaments.
Observatory presentations — a talk inside the Steele Reese Education Center, followed by telescope viewing — are approximately 9:30 p.m. to 12:30 a.m. in July; 9-11:30 p.m. in August; and 8:30-11:30 p.m. in September and October. Those start times vary somewhat because they depend on sunset, and the park sometimes closes the observatory early due to weather conditions or lack of attendance.
Three observatory employees take turns giving the night’s talk, and each has more than one script prepared.
“If you come back, you probably won’t hear the same things,” Long said.
Harman’s July 21 presentation was a collage of topics such as telescope types, light pollution, astronomy apps and constellations easy to see during Idaho’s summer.
How to prepare
If you’re heading to Bruneau Dunes for the stars, you’ll want clear skies. And a nifty website helps you plan ahead. You’ll find the astronomer’s forecast here: http://cleardarksky.com/c/BrnDnsSPObkey.html.
Hour by hour, it forecasts when it will be cloudy or clear for up to the next two days at Bruneau Dunes Observatory, along with transparency, “astronomical seeing,” darkness, wind, humidity and temperature data — and helpful explanations of it all.
If you like the forecast, pack your water bottle, snacks and bug repellent for your trip to the observatory. If you want to join the scorpion walk, bring sturdy shoes for hiking on uneven ground; you’ll be walking quickly in the dark.
If you bring a flashlight or headlamp, be certain it’s one with a red-light mode. After dark, the observatory uses only red lights to maintain visitors’ night vision.
Other conditions being equal, two weekends every month are the best for your observatory visit: the one closest to the new moon (such as Aug. 18-19) and the one closest to the third-quarter moon (such as Aug. 11-12), when it rises later.
Another special date: The Perseids, the most popular meteor shower of the year, will peak on Aug. 12.
No, you don’t necessarily have to drive home in the middle of the night. For Bruneau Dunes camping details and other park information: Parksandrecreation.idaho.gov/parks/bruneau-dunes or 208-366-7919.