This figure shows an actual image of a sunset on Earth compared to artistic representations for the best candidates of potential habitable worlds so far. The image corrects for the size, colors, and brightness of the star and sky as seen from an Earth-like world located in the orbits of these worlds. The size of and colors of the star of Kepler-22 b look similar to Earth because it orbits a Sun-like star. The sunsets of Gliese 667Cc and 581d look much redder because they orbit a red dwarf star, with the sky of Gliese 581d much darker due to its greater distance. The star of HD 85512b is the brightest of all cases although the star of Gliese 667Cc is the biggest.
Image Credit: Prof. Abel Mendez Torres, PHL @ UPR Arecibo