The Dome is Done! Planetarium renovation moving ahead right on schedule

The Burke Baker Planetarium and Friedkin Theater renovation project reached a milestone this week, and we at the museum are brimming with anticipation!

Okay. That’s an understatement. When we first heard the news, we all ran around screaming, “The dome is finished! The dome is finished!” That’s what really happened.

The dome is indeed complete, and it was no basic DIY endeavor. The Houston Museum of Natural Science’s Astronomy department budgeted an hour for the installation of each of the 197 panels installed. The old screen was removed and replaced first with support structures and next with the new screen, piece by piece, snugly tucked into place.

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In a 360-degree shot, the new domed screen over the Friedkin Theater in the Burke Baker Planetarium looks like a giant cue-ball.

It’s a painstaking process, according to Planetarium Producer Adam Barnes, the man behind our 360-degree custom-made films. He’s working on a time-lapse photo record of the installation that should be available on social media in the next couple of weeks. Once the old screen was gutted and recycled, Barnes explained, project crews shot 16 anchor bolts into the primary structure of the dome, then got to work on its “rib cage,” the support structure that holds the curved screen. The lowest-hanging portion was built first, then raised into place using come-alongs and chained to the anchor bolts at about 20 degrees. The front of the support structure is about two feet off of the ground at the front of the theater and about 20 feet in the back, giving the new dome its aesthetically pleasing tilt. Once the bottom rung was installed, the crew worked in a upward to the center of the dome, installing one rung at a time until the last circular piece was set in place at the top.

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With the old screen recycled, the next step is unpacking the scaffolding!

“If you imagine a globe, and the lines of latitude and longitude it’s divided into, that’s what the support structure looks like,” Barnes said. “Each little square gets smaller and smaller and more curved until you get to the center, which is a circle.”

With the bones of the theater set, each white panel was raised and placed, carefully measured and marked for size, then taken back down for shaping. The panels ship separately, pre-painted to a specific color rated to 45 percent reflectivity, perforated to make installing the rivets easier, and oversized for the tightest fit possible. Once each panel was measured, it was clamped onto a curved workbench and whittled down into the perfect shape, then re-hung into its final position.

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One by one, the panels are installed with careful measuring and alignment.

“Then they go on to the next panel,” Barnes said. “Each rivet is placed into one of the perforations, so you can’t see how it’s mounted. It’s flush, and they put a little bit of paint over the tiny metal rivet so it blends in very nicely.”

One by one, the panels were installed around and all the way to the top of the dome in much the same fashion as the supports underneath them. The result is a smooth, seamless screen specially designed for domed projections. While most flat-screen theaters have a reflectivity of between 60 and 70 percent (a mirror would reflect 100 percent of light projected onto it), the dome theater’s lower rating actually allows the image to become sharper, though it may not bounce as much light back into the eyes of viewers.

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“For a dome, you’re shining projectors in front of you but also behind you,” Barnes said. “It’s like looking at an image on a nice, big TV projector screen in front of you and then opening the windows behind you so you can’t see the screen anymore. We call it cross-talk, when the light bouncing off the screen behind you ends up washing out the image in front of you.”

The interference of cross-talk is simply eliminated with a less-reflective screen, maximizing the power of each of the 50 million unique pixels pouring from the Evans & Sutherland Digistar 5 laser projection system. And with the tilt of the dome, guests receive a theater-like experience we’re sure they’ve never seen before.

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Mark on your calendars the grand opening of the newly renovated Burke Baker Planetarium and Friedkin Theater March 11. Don’t miss the show! Be the first to see the brightest planetarium in the world in action!

Author’s note: All photos by Adam Barnes.

Making the Stars: A Brief History of the Burke Baker Planetarium

In July of 1964, the Houston Museum of Natural Science opened its new museum in Hermann Park with modest exhibit space and the Burke Baker Planetarium. A state-of-the-art Spitz Space Transit Planetarium dominated the theater’s center with its flat floor and a few slide projectors. Two star balls connected by cages, swinging in a yoke, generated the moving stars and planets. All programs were live star tours.

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That year the Houston Independent School District began sending students to the Burke Baker Planetarium. In the last 50 years, over a million HISD children have explored the starry night in an experience reaching every HISD student at least once.

For an idea of what the planetarium experience was back in the 1970s, take a look at my first Burke Baker Planetarium brochure. The brochure was a 3-fold with the front and back cover shown below. The address was 5800 Caroline Street. When you called for reservations, you only used seven digits. The museum was free, but the planetarium cost $1 for adults and 50 cents for children. We did two or three shows a day plus morning school shows and thought we were busy. Now we do 13 to 16 shows each day. Notice the map. The passage between the planetarium and the tiny museum was a glassed-in breezeway.  

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Inside the brochure was a description of the planetarium experience. Burke Baker’s gift has now brought the astronomy experience to more than 7.5 million people, including all upper elementary students in the Houston Independent School District since 1965.  

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Below is the fold over section showing our new Margaret Root Brown Telescope, which is still behind my office on the third floor. We need an access across the roof to open it up to the public once again as well as realuminizing of the mirror. The telescope tracked the sun automatically and sent a live image to the planetarium and the Energy Hall in the lower level. We created five new shows each year, but they were much easier to produce than the two new shows we do now. 

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In 1988, the Burke Baker Planetarium was one of the first in the world to go digital. In a capital campaign that funded the Wortham Giant Screen Theatre, the planetarium’s Friedkin Theater became a space simulator with an Evans & Sutherland Digistar 1, the world’s first digital planetarium projection system.

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In 1998, a decade later, the Burke Baker Planetarium was first in the United States and second in the world to install a Digital Sky full-dome digital video projection system. This dynamic immersive environment was funded by a grant from NASA through Rice University. Now the planetarium could offer full-dome animations and movies with a new slightly tilted dome and seats. The planetarium’s Cosmic Mysteries and Powers of Time were among the first full dome digital films produced.

Eighteen years later, the Friedkin Theater of the Burke Baker Planetarium becomes the most advanced True 8K planetarium in the world. On March 11, HMNS will unveil an overhauled theater featuring an all-new, tilted, seamless projection dome and the main attraction, the Evans & Sutherland Digistar 5 digital projection system. This cutting-edge system brings the highest resolution, the brightest colors, and the most advanced spatial imaging technology on the market to the planetarium, restoring its status as best in the world.

Editor’s note: Keep your eyes peeled for more details about the Planetarium renovation on social media, Facebook, Instagram, Twitter, and right here on our BEYONDbones blog. Throughout the month of February and early March, we’ll be posting the latest information about the project until the grand opening March 11. 

The stars at night are big and bright, deep in . . . New Zealand?

Editor’s note: This blog is one of a series of travelogues by HMNS VP of Astronomy Carolyn Sumners, sent from the two-week solar eclipse viewing trip she led to the South Pacific. Astrophotography by Gary Young.

The stars of the southern hemisphere are fantastic, with the brilliant Milky Way stretching from near the hunter, Orion, in the North to Crux, the Southern Cross, in the South.

This predawn image is a time exposure with a Canon Mark II camera and a fisheye lens, taken from our hotel lawn in Queenstown, New Zealand, looking out over Lake Wakatipu. Even with some glare from the hotel and from Queenstown to the East, the predawn sky is remarkably dark. This exposure approximates what we could see as we faced south.

Examining the stars from southern Australia with Dr. Carolyn SumnersNew Zealand has a total population less than 5 million, which guarantees much less light pollution, even close to a city. Also, the southern Milky Way is much richer and more easily seen than the Milky Way near the North Star.  In New Zealand, we trade views of the Big and Little Bears for the Southern Cross and the nebulae around it. This image is a close-up of the southern Milky Way in the early evening as we started stargazing. Notice the dark areas in the Milky Way. The Inca saw animals in these dark dust clouds.

Examining the stars from southern Australia with Dr. Carolyn SumnersWhile observing through two telescopes, we placed our third telescope, a Takahashi FS60Q, on a small portable Sky Patrol equatorial mount that would track the stars — adjusting for the Earth’s rotation. We were able to do time exposures of up to a minute without guidance and we captured incredible views of the Orion Nebula, the Omega Centauri globular cluster, the Large and Small Magellanic Clouds and the Carina Nebula.

Examining the stars from southern Australia with Dr. Carolyn Sumners
Large and Small Magellanic Clouds

Through a telescope we saw the shapes of these clouds and clusters, but not the rich colors and textures captured in these images. The Orion Nebula is a stellar birth cloud with new stars still forming from the gas and dust. The Carina region has young stars and the dying supergiant Eta Carinae.

Examining the stars from southern Australia with Dr. Carolyn Sumners
Eta Carinae nebula

Omega Centauri is the brightest globular cluster in Earth skies with 5 million stars. The Large and Small Magellanic Clouds are satellite galaxies of our Milky Way galaxy. We can see the Orion Nebula easily from Houston. The other magnificent objects are best seen from below Earth’s equator.

Examining the stars from southern Australia with Dr. Carolyn Sumners
Orion Nebula

It’s a wonderful sky down under.

The Celestial Sea

As you look up into a November sky right at nightfall, you may notice fewer bright stars than at other times of year. No, it’s not just the glare from Houston hiding most of the stars from view–there really are fewer bright stars in the November evening sky than in, say, February or August. To understand why, you need to understand the shape of our galaxy itself.

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Creative Commons License photo credit: visualpanic

Our galaxy, the Milky Way, is a barred spiral galaxy.

Evidence indicates that the Milky Way, like many large galaxies, has a massive black hole at its center. A radio source designated Sagittarius A* could be the black hole itself. (The asterisk is part of the name, which is “Sagittarius-A-star”). Surrounding this black hole is a central bulge where older (and thus redder) stars predominate.  The Bulge of our galaxy is not fully spherical but instead forms a bar a few thousand light years long.  Branching out from this bulge are spiral arms which contain younger (bluer) stars and dust clouds out of which brand new stars form.  Our solar system is about 26,000 light-years from the center to the edge, on the inside edge of the Orion Arm.  The Orion Arm, in turn, is but a spur of the much longer Perseus Arm.  The Milky Way is quite flat–over 100,000 light years wide but only 1,000 light years thick.

The flatness of the galaxy means that most of its stars are near a certain plane in space.  Of course, the galaxy is much thicker than our solar system, so we see our stellar neighbors suurounding us on all sides.  The rest of the galaxy, extending off into the distance, appears to us as a hazy blur in the background, with individual stars (those fairly close to us) in the foreground.  That hazy blur looked like spilled milk to the ancient Greeks, thus the name ‘Milky Way.’  We see more stars near that plane than far from it.

What does this have to do with the dimness of a late November sky at dusk?

Imagine observing our flat galaxy from our vantage point on Earth. When we face into the galactic plane, we see more bright stars, because there are more stars in that direction.  When we face above or below that plane, we see fewer bright stars.

Face west at dusk in late November and early December, and you’ll notice an enormous triangle of three bright stars, all bright enough to appear even in skies lit by Houston.  These stars from the Summer Triangle, so called because it is up all night long from June through mid-August.  This Triangle is also directly in the plane of the Milky Way.  The constellation Sagittarius, which marks the center of the Galaxy, sets just after the Sun this time of year.  Therefore, if you trace a path approximately from the  point of sunset through the Summer Triangle, over to five stars in an ‘m’ shape in the North (that would be Cassiopeia, the Queen), and then over to the northeastern horizon.  This is the plane of the Milky Way across late autumn skies at dusk .

Turn to the south, and you face below the galactic plane (as we’ve arbitrarily defined ‘above’ and ‘below’).  Here is a vast region of sky almost void of bright stars.  One exception is Fomalhaut, low in the southeast at dusk tonight.  Also, Houstonians with a very clear southern horizon can see Achernar very, very low in the south on December evenings.  But that’s about it.  There are many fewer bright stars in this direction than towards the Summer Triangle.  By the way, the brilliant object in the east at dusk tonight, and high in the southeast as dusk in December, is Jupiter. It doesn’t count as a bright star for this sector of the sky.

The Celestial Sea

When ancient Mesopotamians looked up into the dim skies you see at dusk tonight, they imagined the Persian Gulf south of them extended up into the sky, forming a ‘Celestial Sea’.  They therefore placed many water-themed constellations in this part of the sky.  Zodiacal constellations here include Pisces, the Fish, and Aquarius, the Water-Carrier.  Even Capricornus, the Goat, has the tail of a fish because he originally represented Ea, the ancient Babylonian god of the waters.  Under Pisces is the sea monster Cetus, while Piscis Austrinus, the Southern Fish, drinks the water that Aquarius pours.  Eridanus, the River, rises in the southeast, flowing from Orion’s foot into this vast ‘sea.’

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Creative Commons License photo credit: paul (dex)

Contrast this vast, dim region with the much brighter swath of stars that rises in the east later this evening (9-10 pm in late November, earlier in December).  This region of sky includes the brilliant pattern Orion, the Hunter, as well as Sirius, the brightest star we ever see at night.    When these stars rise, we are beginning to face back into the plane of our galaxy, this time looking into our own arm of galaxy at the stars right ‘behind’ the Sun.  (This is why our arm of the Milky Way is called the Orion Arm.)  Winter evening skies are much brighter than those of late autumn.