Did you know that most of the images of space you see are photoshopped?
The most important thing to remember, first off, is that these images are not fake, but edited and enhanced for a number of reasons. These reasons are scientific, not just cosmetic, according to astrophysicist Paul Sutter.
One reason is that these images come to us in greyscale, rather than colour. This happens because these images are taken to collect information. Since coloured cameras are of lower resolution than black and white cameras, it makes sense to take these pictures in black and white.
Of course, monochromatic photos aren’t as visually appealing as coloured ones. It’s also more difficult to grasp information in a black and white photograph. So scientists composite multiple filter photos into one image to approximate the real colour.
Frequently, colourisation is also used for categorisation. Colourising photos can help scientists understand more about the elemental makeup of the universe. Different elements give off different wavelengths of light. So it’s helpful to colour-code different elements so everyone can recognise them just by looking at the photo.
Colours are therefore also used to highlight where certain elements are in a galaxy, a nebula or a star.