Sometimes astronomy is unreal. Really. Those spectacular pictures from the Hubble Space Telescope of exploding stars and nebulous gas clouds and stars emerging from dusty cocoons are all―to one extent or another―computer-enhanced. The images are processed, spruced up, airbrushed, and painted like so many Hollywood stars.
People sometimes look through ordinary backyard telescopes and feel betrayed. They don't see enormous green and, purple glowing clouds of gas. Saturn looks mostly black and white. But is it deception, really?
Curiously, when Galileo first looked through his crude telescope and saw mountains on the moon and moons around Jupiter, people thought he was seeing an optical illusion. His telescope, they said, was creating distortions. Anything you couldn't see with your naked eye, in other words, wasn't really real.
Today, we worry about the reality of the things we see through lenses. In fact, many of us walk around with lenses floating on our eyeballs or perched on our noses, the better to see the world. Moreover, we know that the images we see in our mind's eye are exhaustively processed by our brains. The brain rights the upside down images on our retinas, fills in blind spots, erases unnecessary “noise” such as blood vessels and floating bits of fluff from our field of vision. The brain adjusts for motion, “corrects” colors, and puts things in their proper perspective.
In their own way, that's just what the Hubble scientists do. The astronomers have to clean up “noise” in the images, such us cosmic ray tracks, and clear up distortions. What's more, the Hubble, images come down in black and white. They're processed through different filters sensitive to different colors. The astronomers put them back together. That's also more or less the way the human eye works―color-sensitive cells process images, which the brain reassembles.
So it would be difficult to argue that the Hubble images are somehow dishonest. After all, there's no such thing as an unprocessed, unfiltered image. For that matter, there's no such thing as an unprocessed sense perception, be it sight, sound, touch, taste, or smell. The truth of the matter is hard to explain: Yes, the Hubble images are processed, filtered, reassembled, artificially colored, and generally jazzed up. But they are no more jazzed up than the images we see with our own eyes.