Several criteria may define an exceptional piece, among which rarity is the most decisive. Vintage large-format photographs from the early days of space exploration — particularly those from the Apollo missions (and especially, of course, the very first photographs taken on the lunar surface during the historic first Moon Walk carried out on July 20, 1969, by Neil Armstrong and Buzz Aldrin) — rank among the rarest examples. They generally exist in 11 x 14 inch formats, or even more exceptionally in 16 x 20 inch formats, and bear on the reverse the famous ‘A KODAK PAPER’ marking, the first paper used for the large-scale distribution of NASA photographs from the early 1960s until the beginning of the 1970s.
Also belonging to the category of rarities are photographs considered historically important, and therefore rare because they are intensely sought after and seldom offered on the market due to their sometimes unique nature — such as the first medium-format photographs transmitted by the Voyager space probes (revealing Saturn and Jupiter at the dawn of the 1980s) or by Viking 1 and Viking 2 (the first photographs ever taken from the surface of the planet Mars).
Finally, this realm of rare works also includes the most iconic images — or simply the most beautiful — created by mankind and its space probes throughout the still relatively recent adventure of exploring our Solar System, as well as the more distant observation of our galaxy and deep space.