PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011

PHOTO CAPTION                                             P-14580
                                          Mariner 10-31 (Mercury)
                                                    April 4, 1974

This photomosaic of Mercury was constructed of 18 photos taken at
42-second intervals by Mariner 10 six hours after the spacecraft
flew past the planet on March 29, 1974.  The north pole is at the
top and the equator extends from left to right about two-third
down from the top.  A large, circular basin, about 1,300
kilometers (800 miles) in diameter, is emerging from the day-
night terminator at left center.  Bright rayed craters are
prominent in this view of Mercury.  One such ray seems to join in
both east-west and north-south directions.  Taken from a distance
of about 210,000 kilometers (130,000 miles), the pictures were
computer-enhanced at the Jet Propulsion Laboratory.
                              #####