Large format vintage chromogenic print on resin coated Kodak paper, “This paper manufactured by Kodak” watermarks on the verso and NASA JPL caption affixed.

Important photographic evidence of extraterrestrial volcanic activity.

Io is the most volcanically active body in our solar system. Volcanoes on the surface were first discovered by Voyager 1 in March 1979. Taken four months later, in July, these images from Voyager 2 not only confirm the presence of volcanoes but also demonstrate visible changes to the surface in the gap between the two probe’s encounters with the satellite. This proof of frequent volcanic activity on Io led to considerable excitement in the academic community and encouraged further study of this geographically fascinating body.

[NASA caption on reverse] Voyager 2 took this picture of Io on the evening of July 9, 1979, from a range of 1.2 million kilometres. On the limb of Io are two blue volcanic eruption plumes about 100 kilometres high. These two plumes were first seen by Voyager 1 in March 1979, and are designated Plume 5 (upper) and Plume 6 (lower). They have apparently been erupting for a period of at least 4 months and probably longer. A total of six plumes have been seen by Voyager 2, all of which were first seen by Voyager 1. The largest plume viewed by Voyager 1 (Plume 1) is no longer erupting. Plume 4 was not viewed on the edge of the moon’s disc by Voyager 2 and therefore it is not known whether or not it is still erupting. This picture is one of a series taken to monitor the eruptions over a 6 hour period.
11 x 14in. (27.9 x 35.6cm.)

From the personal collection of Dr. Bruce A. Goldberg, an astronomer active with the Jet Propulsion Laboratory (JPL) at Caltech and later the USAF Phillips Laboratory, c. 1970s-1990s.