Fall 2010

A close-up of Astronaut John Grunsfeld shows the reflection of Astronaut Andrew Feustel and the Hubble Space Telescope during a servicing mission in May 2009.
Photo: Courtesy of NASA

Hubble Vision

This fall, Science Center visitors can float alongside astronauts and explore the farthest reaches of the universe in Hubble, an IMAX adventure that celebrates 20 years of the Hubble Space Telescope—and 20 years of mind-boggling discoveries.

By Jennifer Bails

 

In July 1994, 21 fragments of the doomed comet Shoemaker-Levy 9 careened into Jupiter, sending towering mushroom-shaped fireballs of hot gas into the Jovian sky. It was as if an atomic bomb had exploded two dozen times in a single week, unleashing enough energy to obliterate the Earth’s surface. And it was the Hubble Space Telescope that provided a ringside seat to this once-in-a-millennium cosmic event as it unfolded some 400 million miles away.

“To see that collision happen—being there for the first time when an actual comet crashed into a planet in our solar system—was just awesome, truly a historic moment that has always stuck with me,” recalls Dan Malerbo, education coordinator at Carnegie Science Center’s Buhl Digital Planetarium.

For the past two decades, Malerbo has incorporated images of never-before-seen celestial events like this into the Science Center’s marquee astronomy programs, workshops, and classes for students, teachers, and the generally curious—all thanks to the nonstop work of the Hubble Space Telescope. In June, for example, budding stargazers in the Science Center’s weeklong “Awesome Astronomy” summer camp learned how to classify galaxies by shape using images from Hubble.


Hubble, pictured above, captured this extraordinary image this past February. Dubbed “Mystic Mountain” by astronomers, it shows chaotic activity atop a three-light-year-tall pillar of gas and dust that’s being eaten away by the brilliant light from nearby stars.  Photos: Courtesy of NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team

Hubble is one of NASA’s most successful and longest-lasting scientific endeavors, including the five astronaut missions to repair and upgrade the observatory, making the telescope 100 times more powerful than when it was launched in 1990.

“Hubble has really set the high-water mark for our exploration of the universe,” Malerbo explains. “I’ve been an astronomy educator for 22 years, but every time I see a new image from Hubble, I still feel awe.”

The statistics are mind-boggling. In its 20-year life span, Hubble has traveled roughly 2.8 billion miles, hurtling around Earth more than 110,000 times at speeds of 17,500 miles an hour. Not bad for an instrument the size of a large tractor-trailer. Along the way, it has captured some 570,000 images of nearly 30,000 celestial objects in breathtaking detail. The world has watched as image after image revealed another part of the cosmos that would otherwise be invisible to our eyes. And for about as long as Hubble has occupied its lofty perch 370 miles above Earth, Carnegie Science Center has been a key venue  for the public to join in the exploration of the universe made possible by this technological wonder of the modern world.
 
The relationship began shortly after the Shoemaker-Levy 9 impact, when the Science Center’s planetarium production team created Through the Eyes of Hubble. Translated into more than a dozen languages and distributed to planetariums worldwide, the show chronicled the first year of Hubble’s discoveries after the initial repair mission to the telescope. Ever since, Malerbo and his Science Center colleagues have relied on the beauty and mystery of Hubble images—such as the spectacular images of the Pillars of Creation that reveal newborn stars hatching from pockets of interstellar gas in the Eagle nebula 7,000 light-years away—to bring astronomy to life for visitors.

“I can mention that stars are born in clouds of dust and gas, but when you see an image, it really evokes thoughts of how this process occurs,” Malerbo says. “You can see it and relate to it.”

To the edge of space and back

The 43-minute IMAX film Hubble, playing now at the Science Center’s Rangos Omnimax Theater, is narrated by actor Leonardo DiCaprio. It recounts the extra-ordinary life and legacy of the telescope, featuring gripping footage from the fifth and final spacewalking repair mission in May 2009. To accompany it, the Science Center will premiere a montage of Hubble’s iconic images in its Buhl Digital Planetarium.

“At first glance, these images appear to be the product of an artist who has a very large and different imagination,” says show producer Frank Mancuso. “But they are inspiring because they are completely natural, yet it takes human know-how and our special technology to capture them.”

Hubble sees farther and sharper than any telescope in history by solving the centuries-old quandary of atmospheric distortion, which had prevented astronomers from attaining a clear view of the heavens since the age of Galileo.

Shifting air pockets in our planet’s atmosphere blur visible light, distorting the views from even the largest, most optically advanced ground-based telescopes (the reason why stars appear to twinkle). The atmosphere also partially blocks or absorbs other wavelengths of electromagnetic
radiation, such as ultraviolet, gamma, and X-rays, so they are difficult or impossible to view from Earth. The solution: Place a telescope beyond Earth’s fuzzy atmosphere.

That bright idea was first conceived in 1923, when famed German rocket scientist Hermann Oberth speculated about propelling telescopes into orbit. In 1946, Princeton astrophysicist Lyman Spitzer wrote about the scientific benefits of a space telescope, and then worked tirelessly for decades to garner support for the initiative. In 1977, Congress finally approved funding for the  so-called “Large Space Telescope” project, later named in tribute to American astronomer Edwin Hubble, who is renowned for observing that the universe is constantly expanding and for discovering galaxies beyond the Milky Way.

By 1985, the Hubble Space Telescope was ready for space, but the tragic Challenger explosion delayed its deployment until April 24, 1990, when the space shuttle Discovery lifted off with the observatory secured in its bay.

“I can sit at my computer and browse for hours looking at every little patch of sky, and at all the wealth of things that no one had ever seen before Hubble.”

- Jeffrey A. Newman, assistant professor  of physics and astronomy at the University of Pittsburgh

Almost immediately after Hubble’s launch, the now-infamous flaw in the shape of the telescope’s primary mirror was detected. The tiny aberration—just 1/50th the thickness of a sheet of paper—had huge implications. Images appeared blurry because some of the light from the objects studied by the telescope was being scattered.

Three years later, a heroic servicing  mission repaired the optical glitch on the    telescope, which at last began capturing picture-perfect images as promised.

“When Hubble was fixed, it suddenly opened up a new eye on the universe,” says Jeffrey A. Newman, an assistant professor of physics and astronomy at the University of Pittsburgh. “You could look at objects like quasars that, until then, appeared as points of light just like the stars. Hubble was able to show us that they are really black holes in the hearts of galaxies. Without Hubble, we would have to try to guess what these things look like.”


In 1994, fragments from Comet Shoemaker-Levy 9 struck Jupiter (the evidence from Hubble seen below) and were eventually swallowed into the vast Jovian atmosphere. In the image at right, Hubble shows oddball-shaped galaxies engaged in  boxing matches with galactic neighbors, chronicling a period when the universe was younger and more chaotic.  photoS: Courtesy of NASA and ESA

Still more to learn

The Hubble Space Telescope has become one of the most trailblazing and prolific scientific instruments ever built. More than 8,700 scientific articles have been published based on Hubble data. And, according to Newman and countless other scientists the world over, that data has revolutionized our understanding of the universe and our place within it.

By witnessing bursts of light from faraway exploding stars, Hubble helped astronomers discover dark energy, showing that the mysterious energy is shoving galaxies away from each other at ever-increasing speeds. This makes the universe expand at an accelerating pace.

Before Hubble was launched, astronomers had for years tried unsuccessfully to pin down the precise age of the universe. But thanks to the telescope’s keen view, they have been able to measure the brightness of dozens of pulsating stars called Cepheid variables, and through this analysis calculate that the universe is about 13.75 billion years old.

Hubble observations have also been used to locate planets outside our solar system and make the first three-dimensional map of dark matter, which forms the underlying structure of the universe and comprises most of its mass.

“Really, there is no field of astronomy that hasn’t been touched by Hubble,” says Newman, whose own work focuses on the evolution of galaxies and the universe.

The Pitt researcher recently was named a member of an international team of astrophysicists that will have access to Hubble for 902 orbits around the Earth—the longest time the telescope has ever been dedicated to a single project. The scientists will use Hubble to capture images of more than 50,000 distant galaxies in five swaths of deep space to answer long-standing questions about how galaxies began forming 13 billion years ago and how they’ve evolved.  

“There have already been large allocations of time on other telescopes to study these fields, and the Hubble imaging will be the capstone of this research,” Newman says. “It’s always tremendously exciting when you get new Hubble data. I can sit at my computer and browse for hours looking at every little patch of sky, and at all the wealth of things that no one had ever seen before Hubble.”

Newman explains how astronomers hypothesize that galaxies change size and shape when they use up the gas available to form stars. An alternative theory is that, perhaps in certain galaxies with a lot of matter, the temperature is too hot to produce stars. Or maybe energy from black holes blows out gas from galaxies so stars can no longer form.

“We have a lot of suspects for what is causing these transformations, but we just don’t know who the culprit is,” he says. “Hubble will be an essential tool for helping us study how galaxies change over time.”

Understanding those processes could help us trace the past of the Milky Way, Newman says, and make predictions about our own cosmic fate. “The ultimate questions are where did the Earth come from and where did we come from, and the context for that is our galaxy.”

What’s next

NASA is set to fly its last space shuttle mission next February, closing the historic program after more than a quarter-century. With no additional servicing trips to Hubble, the telescope’s components will degrade and its orbit will decay over the next several years. The space agency is now planning a robotic mission to guide its remains safely through the atmosphere into the ocean. But its legacy is sure to live on indefinitely, as astronomers will be studying Hubble data for decades to come in their ongoing quest to understand the cosmos.

The same is true at Carnegie Science Center, where guest speakers will be invited this fall to discuss Hubble, and family science nights are in the works with a focus on the telescope and its remarkable achievements. Every day, the latest Hubble images are broadcast on four large-screen monitors outside the Buhl Planetarium. The multi-media exhibit ViewSpace also shows movies, animation, and breaking news from Hubble and other NASA observatories. Programming is updated regularly through an online feed from the Space Telescope Science Institute in Baltimore, which is Hubble’s science operations center. Using the DigitalSky computer-graphics system at Buhl—available in less than 20 percent of planetariums worldwide—the very latest images from Hubble can also be incorporated on-the-spot into planetarium shows.

Of course, visitors to the Science Center can also count on staying tuned to the latest information about the next science mission on NASA’s horizon—the James Webb Space Telescope. Named for NASA’s second administrator, the large, infrared successor to Hubble will be launched by the Ariane 5 rocket in 2014, with the aim of observing the formation of the very first stars and galaxies in the universe.

The Webb Telescope is NASA’s next-generation orbiting observatory and planned successor to Hubble.

Each time you see a star or galaxy, the light producing that image has been traveling for thousands, millions, or even billions of years to reach you, depending on the object’s distance, so you see the object the way it appeared that many years ago. That’s how we can look deep into space, far back in time. Since the universe is expanding, the farther we look, the faster objects are moving away from us. This shifts their light into the infrared portion of the spectrum, which Webb is being designed to capture, unlike Hubble, which explores the universe at wavelengths ranging from ultraviolet through visible light and into the near infrared. Webb also has a much bigger mirror than Hubble, enabling it to gaze further back in time at light from the early universe. And while Hubble is in very close orbit around the Earth, the new telescope will sit nearly a million miles away, far beyond the reach of any manned spacecraft, where temperatures are cold enough for infrared vision.

“We keep our fingers on the pulse of what is happening with the James Webb Space Telescope and other events at NASA because our goal is to communicate with the public and inspire them,” Malerbo says. “If someone comes in and they see a Hubble show, we hope that we motivate them to dig deeper and increase their knowledge about the universe—and maybe even become space scientists or astronauts.”

Mancuso recounts the story of a woman who approached him after a planetarium show that explained how stars are actually different colors —a phenomenon clearly visible to Hubble, and in some cases, to the naked eye.

“She was almost in tears because, when she was young, she kept telling adults that she could see different colors in the stars, and they kept telling her she was wrong,” Mancuso says. “You hope that kind of light bulb goes off and that we are a part of it.”

Hubble’s Top 10 Major Scientific Discoveries

  1. Its ability to detect stellar explosions called supernovae contributed to the discovery that the universe is expanding at an accelerating rate, indicating the existence of mysterious “dark energy” in space that works opposite gravity.
  2. Observations of Cepheid variable stars in nearby galaxies were used to establish the expansion rate of the universe with great accuracy and calculate that the universe is about 13.75 billion years old.
  3. Hubble provides the deepest view yet into the distant past of the universe, helping us to understand how galaxies evolve and grow.
  4. By peering into nearby regions of star birth in the Milky Way, Hubble revealed flattened disks of gas and dust that are the likely birthplaces of new planets.
  5. When sun-like stars end their lives, they eject spectacular interstellar clouds called nebulae. Hubble revealed the amazing details of this process of stellar death.
  6. Deep images that show individual stars in  other nearby galaxies reveal the history of star formation.
  7. Hubble made detailed measurements of a Jupiter-sized planet orbiting a star other than the sun, including the first detection of the atmosphere of an extrasolar planet.
  8. The dramatic collision of the comet Shoemaker-Levy 9 with Jupiter provided a cautionary tale of the potential danger posed by cometary impacts with Earth.
  9. Hubble observations have revealed that giant black holes, with masses up to billions of times the mass of the sun, inhabit the centers of most galaxies.
  10. Hubble showed that gamma-ray bursts—short, intense flashes of gamma rays believed to occur when a star collapses to a black hole—are the most powerful explosions in the universe other than the Big Bang.
Source: Space Telescope Science Institute,
HubbleSite.org


 
Also in this issue:

Rock Stars  ·  Ordinary Madness  ·  A Nut on the Plane: Marilyn in Midflight  ·  Director's Note  ·  NewsWorthy  ·  Face Time: Mike Hennessy  ·  Science & Nature: Winging It  ·  Artistic License: Opening the Book on André Kertész  ·  Field Trip: Warhol in Coffee Country  ·  The Big Picture