Home   OPOD   What's New   Rays & Shadows     Crepuscular rays     Anti-crepuscular     Cloud shadows     Mountain Shadow     Earth's Shadow     Blue Sky     Sunsets     Sunset Mirages     Green Flash     Moonrise/set     Opposition effect        Mechanism        Earth images        Mars   Water Droplets   Rainbows   Ice Halos   High Atmosphere   Links & Resources   Search - Index                              123456789012345678		Martian Opposition Effect
		Images NASA/JPL       As the Mars Exploration Rover 'Opportunity' descended towards Meridiani Planum on Jan 24, 2004 its parachute cast a shadow on the arid Martian surface. The large image (PIA05146) was taken from an altitude of only 1400m and shows an area about 1.2km (3/4 mile) across. The parachute shadow is the dark circle to the left of the bright rimmed crater at far right. The moving shadow is marked in two of the inset pictures. Surrounding the shadow is a bright area - an opposition effect caused by shadow hiding by Martian soil grains and backscattering effects. This image is possibly the first showing an "Atmospheric Optics" effect on another planet. It was spotted by Hugo Landheer (site) of the Netherlands.