Colourful Mars, March 5, 2008. Mars is usually referred to as the red planet. But it is at best a terra cotta red, really more of an orange. While I was taking this photograph of Mars among the stars of Gemini the Twins a thin sheet of high altitude cloud moved in causing a diffuse glow around the planet and the brighter stars. Sometimes astro photographers use a mist filter on their cameras to simulate this effect because it emphasizes the colours in the night sky. Particularly hot stars look bluish, while slightly cooler ones look white. Mid-temperature stars like the Sun have a yellowish colour.
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