This is a tri-color deep sky image taken of the Eagle Nebula by the Hubble Space Telescope. While the picture itself is amazing, as is the story behind what is in it, what is really cool is how this picture was made. When Hubble takes deep sky images, such as the one above, it is actually taking multiple images using different filters for different wavelengths of light. So all of the different images the telescope takes look slightly different. Since these filtered images are actually black and white, Photoshop or a similar photo editing program is used to create the amazing, colorful images we see of deep space objects.
First, a program called FITS Liberator is used to fine tune the raw, black and white, Hubble image and adjust brightness, etc. In this case, I used three raw images, which were then opened in Photoshop as three different layers of the same image. Once in Photoshop, color (RGB, as the human eye sees color) is added to the images according to their respective wavelengths, meaning the image of the longest wavelength is red, and the shortest blue. Once the images are layered and colors fine- tuned, the three raw images become a colorful finished product. This really is quite and easy process, although I’m sure practice wouldn’t hurt, and anyone can do it!
The “Pillars of Life” are part of the Eagle Nebula in the Milky Way Galaxy. The light shining out of this nebula is caused by ultraviolet radiation, the result of new star formation in the vicinity. Before I mentioned each raw image showing different wavelengths of light, and in the colored images, each color represents the different substances present in the nebula. The sections of the nebula shown in green represent hydrogen atoms, the red is sulfur ions, and the blue is doubly-ionized oxygen. Although some of these colors do not represent the true emitted light from certain substances, it creates an image in which the substances are more easily told apart, as well as enhances the overall detail. The above image shows darker colors surrounding the pillars, indicating the presence of hydrogen and oxygen, while the pillars themselves are largely lighter, reddish hues, indicating sulfur. This nebula is an area of very active star production. The “Pillars” are clouds of gas and dust that essentially act as incubators for new stars. The denser knobs are called EGGs (Evaporating Gaseous Globules), and star formation is occurring in many of these. I find it interesting that even on such an astronomical scale, we still equate the progression of stars to the life we know and the occurrence of evolution and life here on Earth.
NASA, ESA, STScl, J. Hester, and P. Scowen. “Embryonic Stars Emerge from Interstellar “Eggs”” HubbleSite. STScl, NASA, 2 Nov. 1995. Web. 11 Sept. 2013.
“Eagle Nebula.” Wikipedia. Wikimedia Foundation, 09 Sept. 2013. Web. 11 Sept. 2013.
Raw images from: http://www.spacetelescope.org/projects/fits_liberator/datasets/