Seeing Stars with James Wooten: Last Chance for Winter Constellations in April

Starmap April

Jupiter is now high in the east-southeast at dusk. It outshines all stars we ever see at night, so you can’t miss it. 

Mercury is visible just after sunset this month. Face west at twilight, and look low in the sky over the point where the sun sets. Mercury isn’t as brilliant as Venus or Jupiter, but it easily outshines the stars near it in the sky, so it’s not too hard to find. 

Mars is in the south-southwest at dawn. Noticeably reddish in tint, Mars continues to brighten each day until its opposition in May. It has now surpassed nearby Saturn in brightness.

Saturn is in the south-southwest at dawn, above the distinctive pattern of Scorpius, the scorpion. Mars remains close to Saturn this month.

Venus is becoming lost in the sun’s glare. Already, it doesn’t rise until deep into morning twilight, and Venus continues to approach the sun all month.

April is the last month to see the set of brilliant winter stars which now fill the western evening sky. Dazzling Orion is in the southwest at dusk. His three-starred belt is halfway between reddish Betelgeuse and bluish Rigel. Orion’s belt points rightward to Aldebaran in Taurus the Bull. To Orion’s upper left are the twin stars Castor and Pollux, marking the heads of Gemini, the Twins. You can find Sirius, the brightest star we ever see at night, by drawing a line from Orion’s belt towards the left. Forming a triangle with Sirius and Betelgeuse is Procyon, the Little Dog Star. 

Joining the winter stars are stars of spring rising in the east. Look for Leo, the Lion at dusk. Ursa Major, the Great Bear, which includes the Big Dipper, is high above the North Star on spring evenings. Extend the Big Dipper’s handle to ‘Arc to Arcturus’ and then ‘speed on to Spica’. There are fewer bright stars in this direction because of where the plane of our galaxy is in the sky. The area of sky between Gemini and Taurus and over Orion’s head is the galactic anticenter, which means that we face directly away from the galactic center when we look in this direction. Those bright winter stars setting in the west are the stars in our galactic arm, right behind the sun. On the other hand, if you look at the sky between Ursa Major, Leo, Virgo, and Bootes, you’re looking straight up out of the galactic plane, towards the galactic pole. There are fewer stars in this direction.

Moon Phases

Moon Phases in April 2016:

New: April 7, 6:24 a.m.

First Quarter: April 13, 10:59 p.m.

Full: April 22, 12:24 a.m.

Last Quarter: April 29 10:29 p.m.

On most clear Saturday nights at the George Observatory, you can hear me do live star tours on the observation deck with a green laser pointer. If you’re there, listen for my announcement. 

Clear Skies!

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. 

Science Starts with density and distance

A rousing game of “Will it Float?” occasionally played on The Late Show with David Letterman was really just an impressively popular density guessing game. In our recently added Science Start Outreach Program, Discovering Density, we play a similar game, predicting and testing to see what happens when you toss things into a tank of water. The Science Start program is for grades K-2 and travels to schools, daycares, scout groups, and more to educate students with hands-on learning experiences. 

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Sahil tests the hypothesis that a tiny metal car is denser than water and will sink.

The most fun results are the ones that surprise the young students, like a whiffle ball that will not sink even though it is full of holes, a Lego brick (you’ll have to test that one out for yourself), or liquids that can float on or sink through other liquids in a density column.

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Carolyn points out to a class at Passmore Elementary that an object that is floating must be touching the surface of the water in a presentation of the new Discovering Density program.

Making the distinction that density isn’t just about weight or mass or size but instead the comparison between the two can be a tricky concept at first. Similarly, very small and very large numbers, distances, and time scales can be difficult to grasp, so to make it a little easier, you could try holding a planet like Jupiter or maybe Neptune, if you prefer, as we model the vast distances of our solar system and think about scale in Space: Going the Distance.

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Carolyn points out the different types of liquids forming four distinct layers in the density column that she made during the presentation. The density column was given to the group’s teacher after the show so that students could watch it change over time.

Volunteers spread out with their planets to see the relative spaces between their orbits and explore what a model is, why it’s helpful, and what about the model isn’t quite as it is in real life. For our model to be to scale for both the sizes of the planets and for the distances between them is tricky—in a classroom-sized solar system, it’s going to be almost impossible to see most of the planets from most seats, and even the sun seems petite!

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Carolyn holds up a three-foot board that models the planet Jupiter. If Jupiter was just three feet across, the Sun would have to have a diameter of 23 feet!

Book Science Start for your school or scout group today by contacting Greta Brannan at (713) 639-4758 or outreach@hmns.org. For more information on HMNS outreach programs, click here.