August 24, 2013
Most of us have probably seen those beautiful pictures of galaxies and nebulas that seem to frequently show up on websites. Maybe I’m just noticing them more since I’m interested in them. And until I became interested in them I never thought much about how the pictures were taken. The hubble telescope, as well as other research telescopes, get those pictures from special instruments that can detect a wide range of wavelengths….sorta detecting like our eyes but the detectors on the telescopes can receive other wavelengths that we can’t see. You know the antenna on cars? Or in your cell phones? Or satellite dishes? They detect wavelengths we can’t see. The hubble telescope detects all kinds of signals (wavelengths) from ultraviolets to infrareds and beyond. Our bodies do detect ultraviolet and infrared but not our eyes so we do have some special detectors. Our skin can darken from ultraviolet rays and we can detect heat as an example of infrared. But we don’t see those, we only feel them or notice the results later.
Here’s an example of infrared detection here on earth. The colors you see in the picture are industry standard representations that show cool as blue colors and red as warm in these infrared detectors. I previously wrote a post about hot and cool colors which differ from how they are used below.
And here’s an example of an ultraviolet detector for the sun (glasses with photochromic coatings like Transition lenses also work by UV activating):
The hubble telescope detectors are quite a bit more advanced obviously. These telescopes don’t take pictures like our cameras. How then can we explain all the colors in the hubble pictures that we see if they aren’t colors that our eyes can’t detect? What the scientists get from many of these telescopes is a bunch of monochromatic (more than 50 shades of gray too) black and white boring pictures and data (boring to you and me). There’s a lot of artistic license that goes into making these pictures as beautiful as they are and makes them definitely more exciting to look at. That is the purpose too. Astronomers enhance the telescope data to visually represent different gases that are in the nebula or different energies that are detected in galaxies. How these colors are chosen is also somewhat artistic as well. Enhancing depth using contrasting shades helps the overall effect.
If you want to read a little more about how these colorful pictures are created I’ve got some links below! Oh, pictures of Mars more closely represent what we might actually see with our own eyes compared to those galaxy and nebula pictures.
and this one about early artistic methods: http://io9.com/