The Online Photographer: Ten Iconic Photographs: No. 1

[Note: Writer and editor Mike J. is doing well, making a slow recovery from a cornea transplant. For your amusement and edification in the meantime, brief discussions of ten remarkable photographs, counting down from number 10.]

The Hubble Ultra Deep Field Photograph

"This picture is the reason the Hubble Space Telescope was built. It has been compared in significance to the Dead Sea Scrolls and the discovery of the structure of DNA. It is the deepest and farthest back in time that humans have ever been able to see, almost back to the beginning of time."

—University of Texas Astronomer Andy Howell,
about the original 1995 Deep Field Photograph

This is not the prettiest picture ever made, but it is certainly one of the most amazing. It is a picture of a tiny, nondescript patch of sky with "nothing in it," in the constellation Fornax, below Orion. To put its angle of view in perspective, science writer Chet Raymo explains, take two pins or sewing needles and, at arm's length, cross them. The small square where the two pins overlap is approximately the visual area represented by the Hubble Ultra Deep Field photograph.

So why is this a great photograph? Well, for one thing, it shows something that is only visible to human beings through photography. It is a million-second exposure created from two separate images, each made with hundreds of exposures, taken by Hubble's Advanced Camera for Surveys (ACS), installed in the 2002 servicing mission, and the Near Infrared Camera and Multi-object Spectrometer (NICMOS), which sees even farther than the ACS.

It uses the world's most expensive lens.

The world's most expensive camera: the Hubble Space Telescope

It is the ultimate in difficulty of access; unlike most photographs, it is not something that was ever witnessed directly by a human being. It essentially exists for us only as a photograph. Certainly, none of us will ever visit the place from which it was made.

The picture contains some 10,000 galaxies, and shows us as far back in time as we have ever seen: a redshift of approximately 7–12 (about 400–800 million years) from the Big Bang.

Each of these galaxies, of course, comprises millions of individual stars. The objects it shows are between 2.5 and 10.5 billion light years away. To put us in context—an absurd concept, since that simply can't be done—consider that Voyager 1 has been traveling at approximately 55,000 miles per hour since 1977 and just recently left the earth's solar system. Assuming it could keep going that long, it would require another 400,000+ years before reaching a second solar system. Just try to extrapolate that kind of scope and scale out to encompass 10,000 galaxies in a patch of sky that can be covered by two crossed needles held at arm's length. The human imagination is far too paltry a thing.

William A. Anders, Earthrise, Apollo 8 mission, Christmas Eve 1968

There are other photographs from space that perhaps move us emotionally to a greater degree; the sentimental favorite is no doubt one of the many "Earthrise" photographs taken from the orbit of, or the surface of, the moon. No wonder, as it shows a portrait of our own little neighborhood: Earth, our only home, almost unbearably lovely. Personally, I consider it a great privilege and great good luck to have lived in an era when I could see such a picture.

But for pure awe, it is dwarfed by the magnificent HUDF. No single tool in human history has revealed as much to us about the Universe as the Hubble Space Telescope. One can argue that it is the ultimate camera, and this astounding photograph its banner achievement. It encapsulates, in photography's specifying, limiting fashion, the mysteries of the Universe.

Hubble Deep Field multi-variate display at the Advanced
Supercomputing Project at NASA Ames, 1995.