About Carolyn S

Carolyn is VP of astronomy for the Museum; she develops Planetarium shows for the Museum that tour all over the world, developed the very first Challenger Learning Center and runs the Museum’s George Observatory in Brazos Bend State Park. In her spare time, she does research in the field of archaeoastronomy, which attempts to replicate the night sky at critical moments in history.

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

Published by Carolyn S on December 6, 2012 at 11:53 am in Astronomy

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.

New 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.

While 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.

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.

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.

Orion Nebula

It’s a wonderful sky down under.

Start a new holiday tradition throwing ornaments! All about boomerangs, with recent expert Carolyn Sumners

Published by Carolyn S on December 5, 2012 at 4:24 pm in Astronomy

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 Australia.

Australian Boomerangs

When in Australia, it’s important to master throwing a boomerang, or at least give it an honest try. Everyone on our eclipse tour group attempted a boomerang throw with some success, depending on the amount of spin and the angle of release. Here I am trying to master the technique with an expert teacher:

In case you find yourself with access to a real boomerang, here’s the secret to a successful throw:

1. The Spin
Hold the boomerang with the painted side toward you. When you release the boomerang, give it as much spin as possible. Hook your index finger around the tip. Holding the boomerang firmly, let it tilt back against your wrist. When releasing the boomerang, give it a quick throw — keeping your hand closed so the boomerang rolls around your index finger and is aimed slightly upward.

2. The Angle of Release
Face about 45 degrees to the right of any oncoming breeze (left if you are throwing left-handed with a left-handed boomerang). Lean the boomerang over about 30 degrees and throw at this angle. (Do not release the boomerang horizontally. Such a throw can damage the boomerang.)

For a real wooden two-bladed boomerang, you need a large open area for throwing. You will improve by increasing the spin of the boomerang and getting the best angle relative to the wind. Catch a returning boomerang by bringing your open hands together on either side of the spinning boomerang.

Real boomerangs come in various shapes with two, three, or four blades. Boomerangs are often used to knock birds out of trees and will not usually come back after impacting with another object.

Space-Saving Boomerangs

If you want a boomerang that returns in a very small space and cannot hurt anyone, use the attached pattern for a 4-bladed boomerang. Draw the boomerang pattern on card stock and cut it out. Curve the blades inward, shaping the boomerang as a plate or shallow bowl.

Hold the boomerang vertically with the tip of one blade between your index finger and thumb. Tilt the boomerang back until it touches your wrist. The inward curve of the blades should face the center of your body. In my photo (taken in New Zealand, where we finally practiced our boomerang throwing), you can see the proper position for a left-handed thrower. The right-handed throw is the same, with the boomerang blades still curving inward.
Flip the boomerang straightforward with as much vertical spin as you can. When thrown with enough spin, this boomerang will always turn from vertical to horizontal and come back to you. Usually this will happen within 10 feet of you.

This boomerang can also be decorated and hung on a tree for the holidays!

Boomerangs in Outer Space

Being the astronomers that we are, we wondered if this boomerang would come back in outer space. We discovered that our reliable 4-bladed lightweight boomerang did depend on gravity to turn it from vertical to horizontal. This boomerang did not return on the International Space Station. However, a 3-bladed boomerang made of heavier material with tilted blades did return in the ISS. Watch this video to see space boomerangs in action. (Note: you must scroll to the second page of the link to find the boomerang video.)

Make boomerangs for the whole family and start a new holiday tradition from down under.

Killer crocs and cute koalas: Going to extremes with Australian wildlife

Published by Carolyn S on November 17, 2012 at 11:30 am in Zoology

Australian wildlife is full of surprises. I first discovered that crocodiles look a lot like alligators, but with a very different attitude toward humans. A trip to the museum’s George Observatory in Brazos Bend State Park often features an encounter with an alligator sunning on your path or floating like a log at the water’s edge in Creekfield Lake. You’re warned to keep dogs on leashes and leave the gator alone, but no fences restrain you or the gator.

Australian crocodiles are more aggressive, and unfortunately recognize humans as food. Fencing confines all the crocodiles at Hartley’s Crocodile Adventure near Cairns, Australia. And a boat ride in crocodile-infested waters requires all hands inside the boat with Plexiglas windows on all sides.

An alligator show often features the handler taping the gator’s mouth shut and actually sitting on the patient gator. In contrast, a crocodile show is billed as a “Crocodile Attack Show.” It usually features only one crocodile that must be distracted when the keeper dashes across an open area to the protected spot for the feeding. There’s nothing leisurely about a crocodile jumping for food or initiating a death roll when the food is attached to a rope that the keeper does not release.

After grabbing the bait, we watched a croc rolling under the water, a technique designed to disorient and drown its prey. This “death roll” allows a croc to feast on large animals at its own pace. As the late Steve Irwin said, “The crocodile death roll is potentially the most powerful killing mechanism on Earth.”

Koalas are as cute as crocs are deadly. Koalas are marsupials native to coastal regions of Australia. Like all marsupial babies, baby koalas are called “joeys.” At birth, a koala joey is the size of a jellybean! It has no hair, no ears, and is blind. Joeys crawl into their mother’s pouch immediately after birth and stay there for about six months. At Hartley’s Crocodile Adventure, we petted the soft fur of a female koala and watched an 11-month-old Joey still clinging to its mother’s back. Back in Houston, our only marsupial is the lowly opossum, which just doesn’t compare.

Reporting from Down Under: It’s a solar eclipse shark attack in Australia

Published by Carolyn S on November 15, 2012 at 2:27 pm in Astronomy

I had never realized before that a photograph of a partial solar eclipse behind lots of colorful clouds at sunrise looks so much like a shark attack. Especially if you’re watching it over the Pacific Ocean with about 40,000 other people in Cairns, Australia.

See the fin?

In my nine eclipse expeditions, I have never seen these unique atmospheric conditions before. Traditional knowledge suggests it’s best if your solar eclipse view is cloudless, with the sun’s corona surrounding the moon’s black disk at totality. But if clouds spoil that view, I discovered that dramatic images can hide in the cloud decks, especially if the clouds are thick enough to filter the sun’s light (effective neutral density of four or greater) and allow a camera to capture images without a solar filter. (Safety note: We kept solar filters ready at a moment’s notice if conditions improved. We also viewed only through the LED display of the digital camera, not through the viewfinder.)

The museum’s solar eclipse travelers had a front row seat from the balcony of their rooms on the 11th floor of our Australia hotel. Boats had anchored in the harbor below us, and eclipse watchers camped on the boardwalk by the water. The event became a dynamic interplay of clouds and the partially eclipsed sun. Sunrise began with decks of clouds drifting between the sun and us. We aimed cameras mounted on telescopes to the place where we knew the sun would appear when the clouds parted.

The view from out hotel balcony at 6 a.m., when the sun was just clearing the peninsula’s tallest peaks. The Takahashi FCT-76 is on the left and the FS-60 is on the right, riding on a Sky Patrol equatorial mount.

Rays of sunlight through cloud decks also showed the sun’s location. As the beams moved across the land, we knew it would soon be our turn to see through a tiny thinning of the clouds just before totality. As totality approached, the sky gradually darkened and the temperature dropped. The city lights below us had just turned off at sunrise and now flickered back to life. Flash bulbs blinked over the city as photographers hoped in vain to light a path through the clouds. For the two minutes of totality, the rays of sunlight vanished, the clouds became black shadows and a sunrise glow illuminated the horizon. Then daylight returned, and we looked to see if our cameras had captured anything our eyes had missed. That’s when we discovered the shark fin shapes of the partially eclipsed sun appearing to sail behind a fantastic display of pale hued clouds. Did we have the best view of totality? Maybe not. But in the interplay of thick colorful cloud decks, we were treated to a very rare unfiltered solar eclipse at sunrise.

Photographs tell the story better:

Here I’m focusing the Celestron 5 telescope. Next to me is the Takahashi FCT-76 and the Takahashi FS-60 is closest to the camera.

At about 6:20 a.m., the partially eclipsed sun peeks through the clouds. Photography through a Celestron 5 with focal reducer (focal length 800mm).

The shark’s fin is the sun’s disk, partially covered by the moon and by several banks of Earth clouds. Photography through a Celestron 5 with focal reducer (focal length 800mm).

At about 6:25 a.m., totality is just over 10 minutes away. The colors become more dramatic as the sunlight level drops. Photography through a Celestron 5 with focal reducer (focal length 800mm).

The camera cuts off most of this shark fin, but notice the sunrise colors lingering in the clouds. Photography through a Takahashi FCT-76.

At about 6:30 a.m., the clouds and colors become dramatic as totality nears.
Photography through the Takahashi FS-60 at 600 mm focal length.

Four and a half minutes later, as totality approaches, the clouds darken, with only the closest illuminated by the last rays of the sun’s photosphere and perhaps the first faint glows of the corona. Photography through the Takahashi FS-60 at 600 mm focal length

At 6:38 a.m., totality began and the clouds obscured the fainter corona. The sky became as dark as a full moon night with sunrise colors streamed across the horizon.