Spitzer enabled us to look clear across the Milky Way for the first time. You can surf through this composite, infrared mosaic by visiting the GLIMPSE/MIPSGAL Image Viewer.

Photo courtesy NASA/JPL-Caltech/Univ. of Wisconsin

Astrophotography in Orbit

Now that we've explored the down-to-earth perspective, let's examine the functions of astrophotography in orbit. Probably the most familiar photographs taken in space have come from the Hubble Space Telescope. However, the Spitzer Space Telescope, the newest and final telescope of NASA's Great Observatories program, has been stealing the show lately.

Originally called the Space Infrared Telescope Facility, Spitzer launched from Cape Canaveral in August 2003. In June 2008, Spitzer's masterpiece was unveiled. The telescope collected more than 800,000 photographs in several varying infrared wavelengths which were composited and stitched together to create a gorgeous, false-color map of the galaxy [source: Clavin].

Spitzer's imaging abilities see clear to the other side of the Milky Way by accessing the infrared portion of the electromagnetic spectrum. Infrared frequencies lie between those of microwaves and visible wavelengths (what we perceive as light) on the spectrum. These images must be false-color because people can't see anything at infrared wavelengths. You can learn more about light and its frequencies by reading How Light Works. Hubble was used to observe ultraviolet, visible and near-infrared wavelengths, but only with Spitzer have we been able to jump through the cosmic dust and clutter to see distant reaches of the galaxy with such amazing clarity.

And with that sight comes amazing revelations. Researchers can now sift through a wealth of details concerning the layout and composition of the galaxy. For instance, early study of the Spitzer images is giving researchers a clearer idea of the Milky Way's shape. These pictures suggest that the Milky Way is a barred-spiral galaxy, leading scientists to believe it has only two major spiral arms, which extend from each end of the long central bar. This is an evolution from early theories about the Milky Way. For many decades, we pictured it as a four-armed, spiral galaxy with a central galactic bulge. More recently, astronomers theorized our galaxy was a barred-spiral galaxy, but one that still boasted four major arms.

The other NASA observatories orbiting the planet have also played their parts in expanding our knowledge of the universe. Perched high above the corrupting interference of the atmosphere, they transmit images received prior to atmospheric disturbance. For example, Hubble's phenomenally high-powered imagery of the cosmos has increased our understanding of both near- and deep-space objects. The Chandra X-Ray Observatory has been busy gathering information on cosmic phenomena such as supernovas and black holes, and will continue to do so until at least the year 2009. The Compton Gamma Ray Observatory, in operation from 1991 to 1999, cast its lens toward solar flares, quasars and various cosmic interactions.

Now that you know about the world of astrophotography, will space become your muse? Learn more about astrophotography and space by visiting the links on the next page.