Behold: the Andromeda galaxy, NGC 224 aka Messier 31 – our closest galactic neighbour, before and after image ‘cleanup’. To wit:
The picture is a stack of 223 images, each a 300 second exposure, taken from a garden observatory in Portugal over the past year. Obvious image deficiencies include bright parallel airplane trails, long and continuous satellite trails, short cosmic ray streaks, and bad pixels. These imperfections were actually not removed with Photoshop specifically, but rather greatly reduced with a series of computer software packages that included Astro Pixel Processor, DeepSkyStacker, and PixInsight. All of this work was done not to deceive you with a digital fantasy that has little to do with the real likeness of the Andromeda galaxy (M31), but to minimise Earthly artefacts that have nothing to do with the distant galaxy and so better recreate what M31 really does look like.
(Image: Kees Scherer)