PR With Universal Appeal

The postcards from the farthest reaches of the universe stream back to planet Earth each week from the Hubble Space Telescope -- rainbow-hued clouds of nebula gas, sparkling lilac dust on the arms of pastel galaxies, blazing red stellar outbursts.

The Hubble images are the sharpest and most detailed of the cosmos ever seen; snapshots of cataclysmic events occurring billions of light-years away in a dance of color and light that seem almost too good to be true.

They are.

The planets, nebulae and galaxies really are out there but their breathtaking colors are, in most cases, exaggerated. They are the product of a team of NASA astronomers, computer artists and public-relations folk who touch up and color Hubble’s photographs, massaging each one until it is, in the words of one scientist, “just right.”

It’s a merger of science, art -- and marketing.

Zoltan Levay, one of Hubble’s first photographic artists, describes the production of the colorful Hubble images as a “reconstruction process.” Hubble sends its snapshots back to Earth in grainy black and white, and then Levay and other artists at the Space Telescope Science Institute clean up the images and digitally colorize them.

Sometimes, the colors are close to reality, but often, artistic liberties are taken. And whenever there exists the option to choose a color that generates an image of mind-boggling beauty over one that yields more mundane results, the scientists are unabashed about saying that the more aesthetically pleasing option always wins.

“It’s hard to tell the story if you don’t have a stunning image to back it up,” said Ray Villard, the public-relations director for the $1.5-billion telescope. “You can go out of your way to be incredibly accurate, but if people come away and haven’t learned anything, then what was the point?”

The point, according to some people, is that by enhancing the hues of the universe, Levay and Hubble’s other photographic artists have inadvertently created a public misperception that the heavens are bursting with color -- an exciting, enticing, action-packed, Technicolor cosmos worth spending billions of dollars to see more of.

Any photographer at a newspaper, including this one, would be fired for using digital technology to substantially alter a picture. And any scientist doctoring research data would be cast into scientific oblivion.

Hubble’s artists aren’t the only group colorizing the universe. Ground-based observatories and other space telescopes, such as the Chandra X-ray Observatory, also enhance their images, but Hubble is by far the most powerful force in creating the public vision of the universe.

Levay argues that the motive is not to deceive but rather to illuminate a universe that is muted in gray scale and hidden in light invisible to human eyes.

And while the colors may not be entirely true, Hubble supporters say it’s a small concession to keep the dream of space alive

“Big science,” said Caltech astronomer Shri Kulkarni, “requires big publicity.”

It may seem odd that the awesomely infinite universe needs to be touched up, but it does.

The plain truth is that although Mother Nature dots outer space with stunning subject matter, she has a clever way of hiding it. Myriad cosmic wonders lurk to either side of the visible spectrum’s thin sliver. Pulsars, for example, beam their powerful signals in radio energy, while the dust-choked galactic core of the Milky Way is revealed almost exclusively in the infrared.

The universe is also a pretty dim place, making nebulae, galaxies and distant moons appear grayish to the naked eye -- even through powerful telescopes. “If you hopped in a starship and traveled to these objects, they’d still look gray,” Villard said. “These are things that we can never see with the limitations of the retina.”

NASA set out to reveal the hidden universe by arming the bus-sized Hubble Space Telescope with an array of infrared, ultraviolet and visible light detectors. The telescope was launched in 1990 and placed into an orbit 380 miles above the Earth, where it is not affected by the light-distorting atmosphere.

Hubble’s 8-foot mirror allows it to peer nearly all the way across the 13.7-billion-year-old universe and see distant objects as they existed less than a billion years after the Big Bang. The collision of galaxies hundreds of millions of light-years away appears so clearly that astronomers can see the long arms of glowing dust being yanked in a monumental tug of war.

The bounty of images from the visible and invisible universe posed a dilemma for NASA’s scientists: How do they show their discoveries to the taxpayers who foot the $250-million annual bill for the telescope?

“It’s like translating poetry from another language,” said Keith Noll, an astronomer at the Space Telescope Science Institute in Baltimore. “Hubble speaks 50 different languages, and we only speak one, the language of our eyes.”

Levay is Hubble’s translator.

The boyishly inquisitive 50-year-old amateur photographer began his NASA career in 1978 as a data analyst at the Goddard Space Flight Center in Maryland.

After five years at Goddard, he moved on to NASA’s fledgling Space Telescope Science Institute, an astrophysics center created to manage Hubble’s scientific research. He was later drafted to help “paint” the Hubble images for public release because of his combination of computer and photography skills.

Displayed on his computer monitor in Baltimore is a black and white image of the Trifid Nebula -- a dusty cloud of gas 5,200 light-years away that contains the remains of countless stellar explosions. Like a tree in a snowstorm, the image is lost behind a flurry of white streaks and bright spots.

This raw image from Hubble has been attacked by cosmic rays, tiny energetic particles that randomly strike the cameras from all directions, saturating the detectors and leaving bright white trails in their wake.

A click of the mouse brings up a slightly better picture. A computer program removes the “snow” by comparing two images of the nebula and erasing any elements that are not in both.

The new image lacks the grainy appearance, but its gray haziness masks the secrets locked away in Trifid’s clouds.

Levay pulls up three “cleaned” images of the nebula taken through Hubble’s different camera filters. These photographs, taken in black and white, were captured almost a year ago by astronomers who were not interested in taking a pretty picture of the Trifid, but in learning more about the energetic gas within its dusty clouds.

Because gases radiate different colors of light when energized, astronomers use Hubble’s toolbox of colored glass filters to dissect the heavens. For example, hydrogen -- the universe’s most abundant element -- glows at the red end of the spectrum of light visible to the human eye, while doubly ionized oxygen (oxygen with two electrons missing) makes its presence known in teal. So astronomers use a red filter to study hydrogen and a blue-green one for oxygen.

The three filters Levay selects for the Trifid’s representative image are hydrogen, doubly ionized oxygen and singly ionized sulfur (sulfur with one electron missing). He then assigns them each a color -- red, green or blue. When mixed, these optically pure colors yield several million different hues, from the deepest violet to the palest pink.

Levay assigns red to hydrogen because it is the more abundant of the three gases. The oxygen image he “paints” blue.

So far, he has been fairly true to the natural colors, but now Levay is faced with a problem: Doubly ionized sulfur glows a deeper red than hydrogen, but the only color left in his palette is green. It’s not an entirely accurate combination, but it’s the most natural one that Levay can construct with only three optically pure colors.

When the green sulfur and blue oxygen layers come together, the fuzzy gray nebula becomes an unsettling shade of turquoise. One last click of the mouse adds the final scarlet hydrogen gradation, and the nebula is revealed as a turbulent stellar birthing ground, billowing with enough hydrogen fuel to keep its newborn stars sparkling for billions of years.

Levay has just translated the cosmos.

The final decision -- which way is up -- is definitely more art than science because there is no “up” in space: Hubble’s photographic artists orient the images according to their own feelings about what is most pleasing to the eye.

Sometimes, the orientation is immediately agreed upon, but often Hubble’s imaging team will spend hours debating the most appealing, and in some people’s opinion, the most marketable look.

“It is definitely marketing,” said William E. Burrows, the author of “This New Ocean: The Story of the First Space Age.” “But it is no less justified than the military putting on air shows to get young people to enlist. Everybody is selling something -- NASA is selling space and this is one way to do it.”

NASA has many reasons to “sell space,” not the least being to help justify the agency’s annual budget of $15 billion.

“NASA has been at the forefront of marketing their world, and there is nothing wrong with marketing a good idea,” said Felice Frankel, an MIT science photographer. “Somebody there knew how powerful images can be to get people on the side of research. NASA has found this language that makes astronomy accessible, and it has worked because they continue to get major, major funding.”

But how far should NASA go in its effort to make the public aware of the scientific mysteries that Hubble is uncovering?

If a picture is scientific in origin, most people assume that it must be accurate, Frankel said. Although NASA is not hiding the imaging process (it is detailed under “gallery” at www.hubblesite.org), she said that the space agency, along with the magazines and newspapers that reproduce the images, are not doing enough to tell the public about the colors.

“All of those images should be captioned and say ... that the colors were generated digitally,” Frankel said.

At National Geographic magazine, Hubble shots have been published in the past carrying an explanation that the colors were digitally enhanced. But Bill Douthitt, an editor at the magazine, said future articles probably wouldn’t carry that information because the magazine had previously described the coloring process. Instead, they can dedicate more space to science, he said. (The Los Angeles Times also does not note the colorizing of Hubble images.)

The Hubble scientists often wrestle with the confusion that may arise when they create a “natural” or “representative” image. They don’t want to mislead the public, but, Villard said, they also don’t want outer space to look “boring.”

“I would draw the line where the color really could lead to some serious scientific misperception,” Villard said.

Levay likens the process to nature photography, in which images are often adjusted to make subjects look more ideal. In the Kaufman Focus Guides, a series of books used by bird watchers to help them identify their targets, photographer Ken Kaufman modifies his images to enhance identifying marks.

“Different field marks [of the bird] may not be showing up as prominently as he would like, so he’ll touch them up so that they are visible,” said Lisa A. White, an associate director at Houghton Mifflin, the publisher of the guide books. “He’s aiming for an ideal version of the bird.”

Levay is aiming for a more illuminating view of the universe.

In the Trifid Nebula picture, it would have been more accurate to use two shades of red for hydrogen and sulfur. But then, the star-forming region that he knew was there would not have been revealed.

Legions of Hubble fans would probably agree with his decision.

Mike West, a telescope dealer for Oceanside Photo and Telescope near San Diego, said he often gets customers who buy telescopes expecting to peer into the sky and see the striking colors and details that Hubble images depict.

When all they see is the plain old universe, some return, complaining their telescopes are broken.

“All the time we deal with that,” West said. “If they are expecting to see stuff like what the Hubble sees, they will come back.”