TES Team/MGS/JPL/NASA
In 2001, Mars’ opposition and closest approach to Earth occurred soon after it reached perihelion, or closest approach to the Sun. This turn near our parent star kicked up giant dust clouds that covered the Red Planet, frustrating telescope observers who hoped to catch a glimpse of shiny polar caps and study Mars’ bright and dark features.
To create the image above, the orbiting Mars Global Surveyor spacecraft measured both the temperature and amount of atmospheric dust with its Thermal Emission Spectrometer. Blue represents a clearer atmosphere, and red a dust-filled martian sky.
