Red, White, and Blue in Space Photography

The image above might look like something many Americans will see at a 4th of July fireworks display. They depict a single galaxy, named the Southern Pinwheel Galaxy, or Messier 83, processed in red, white, and blue. What is the significance of these colors?
In the case of the American flag, the colors were originally not assigned any meaning at all and perhaps were chosen simply to mimic the colors of the British flag. It was only later, when the country adopted an official U.S. seal, that the colors were assigned meaning. “White signifies purity and innocence. Red, hardiness and valour, and Blue… signifies vigilance, perseverance & justice,” declared Charles Thomson, Secretary of the Continental Congress in 1782.

Those who process astronomical images, which are almost always black and white in their raw form, also face the decision of assigning meaning to colors. Sometimes, images are processed with an eye for artistry and aesthetic appeal, as in many of the beautiful, rainbow-tinged images from the Hubble Space Telescope.
More often, color is used to reveal a particular feature of an astronomical object, as the Hubble Telescope’s site explains. Depending on the instruments used to capture the images, an image might be composed of visible light, as human eyes can see, or any variety of the wavelengths of light which are invisible to us, such as infrared or x-rays. Standard practice is to assign colors based on “chromatic order,” mea...

Source: TIME.com: Top Science and Health Stories - July 1, 2016 Category: Consumer Health News Authors: Marisa Gertz Tags: Uncategorized 4th of July Galaxies independence day NASA Science space space photography Source Type: news