Extrasolar planet Upsilon Andromedae d lies in the habitable zone and if sufficiently large moons of Upsilon Andromedae d exist, they may be able to support liquid water, as the image shows. On the horizon of this hypothetical moon can be seen Upsilon Andromedae d, possibly a class II planet (Sudarsky classification): since it is too warm to form ammonia clouds this ones are made up of water vapor, white in colour instead of the caracteristic yellow-reddish clouds of Jupiter and Saturn. Image Credit: Lucianomendez