Smithsonian Report, 1939. — Jones 



Plate 3 



1. Photographs of Mars in Ultraviolet Light. Showing Atmosphere 

 (left). and in infrared light, showing surface (right). 



Opposite halves are juxtaposed below, to show larger size of ultraviolet image, due to the considerable depth 



of atmosphere. 



^^^ IhS i^^^ 



2. PHOTOGRAPHS OF MARS IN ULTRAVIOLET. GREEN. YELLOW (ABOVE), RED, 

 INFRARED. AND VIOLET (BELOW). 



The surface details become progressively clearer with increase in wave length of light. The rotation of the 

 planet (the direction of the axis indicated in the first image) causes the dark markings to move across the 

 disk. The cloud, shown faintly near the center of the disk in the first image, is beginning to form near 

 noon; in the last image it is well shown near the limit, havng become strong by late afternoon. 



