The results of these experiments supported the hypothesis that cosmic rays and other high-energy particles bombarding the primitive atmosphere could have been responsible for the origin of life on Earth. The experimental devices were constructed and donated by Cyril Ponnamperuma and the Laboratory of Chemical Evolution, University of Maryland. Photomosaic Globe of Mars [Illustration: 16. Photomosaic globe of Mars made of more than 1500 computer-corrected pictures taken by _Mariner 9_ in 1971 and 1972. The residual North Pole ice cap is at the top.] This 1.2-meter (4-foot) diameter globe of Mars was assembled from photographs taken by _Mariner 9_, an unmanned spacecraft that orbited the planet from November 14, 1971, until October 27, 1972. This globe is the first such photomosaic ever made of a planet. Launched on May 30, 1971, _Mariner 9_ succeeded in photographing the entire surface of the planet. In its 349 days of orbit around Mars, _Mariner 9_ circled the planet 698 times and took more than 7300 photographs. In its highly elliptical orbit, _Mariner 9_ obtained a sequence of overlapping wide-angle photographs. These were processed by a computer to remove the known variations in _Mariner 9_ camera response and geometric distortions, as well as to enhance surface detail. The mosaic made from the processed photographs is a pictorial presentation of the Martian surface which shows ridges and craters in the dark regions and on the bright polar caps with equal clarity. Surface features are in correct relationship and perspective, with only a minimum of shading difference between individual photographs. In assembling the photomosaic, each picture was taped in place on the globe. Then, the match of adjacent pictures was assessed to determine where to trim the edges so that sharp features would not be intersected. The edges of each print were feathered so that when the prints were glued into place, the lines between pieces were almost indistinguishable. The complete globe received a thin protective coating. This globe and copies of it enable scientists to study the geology and morphology of Mars from a perspective never before possible. The photomosaic globe was designed and assembled at the Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California. The Mars Globe is on loan from the National Aeronautics and Space Administration. Mariner 10 [Illustration: 17. _Mariner 10_ returned data and photographs from the vicinities of Venus and Mercury.] [Illustration: 18. This computer-enhanced image of Mercury’s surface was returned by _Mariner 10_ from 200,000 kilometers (124,000 miles) and 6 hours away from closest approach to Mercury on March 29, 1974.]