Once of the more enduring, albeit least contentious debates in the hobby, has been over the issue dates of two blue backed sets, Space Cards and Target: Moon, the latter of which was also reissued in slightly altered format in 1967 with salmon backs and a whole lot of skip numbering. You will recall these are alleged to be identical sets when referring to the blue backed Target: Moon cards, with just the name of said set altered on the reverse, but it ain't so.
Here is an obverse of card #34 in all three sets, Moon Explorers:
The Space Cards reverse looks like this:
Meanwhile, Target: Moon #34 had a back that, in addition to the set name change, also had a title change but only on the reverse, the only card I can find like this across all three sets, excepting some contractions of longer titles:
In case you were wondering, Space Cards #33 refers to Card #34 as Lunar Expedition, so that was clearly what Topps wanted to call it. But the front on Target: Moon is still entitled Moon Explorers! It's the same with the salmon back cards reissued in 1967 although card #33 was not released in that configuration and we can't see what it was calling card #34 in the preview line. Here it is:
The front still says Moon Explorers, which is now in error twice, over a span of several years.
I promised a couple of posts ago to show why Target Moon came out after Space Cards, which was the actual point of this post, so take a look at this Space Cards wrapper:
It looks a little weird because there is another wrapper under it but ignore that. Instead, compare it to this Target: Moon wrapper proof (which is the same as the issued version except for the printer's lines):
Notice anything different besides the set name? The Bazooka ad has changed slightly and it gives us a huge clue as to which came first. Here is a closeup of the Bazooka piece in the ad:
I really fuzzed it up when expanding but you can see the upper left corner reads "The Atom", reflecting Topps' Atom Bubble Gum ad campaign of eleven years duration. Now look at the Bazooka piece from the Target: Moon wrapper:
It says Topps. "The Atom" was dropped in mid 1958 and replaced by "Topps", probably due to the very real threat of nuclear war with Russia at the time. We know Space Cards came out in 1957 and now we know Target: Moon came out after the middle of 1958. Target: Moon by the way, is card # 7 in all three sets. My guess as to the issue date of the Target: Moon the set is about 1962 but that is a story for another day (since it's in an article I have in a recent issue of The Wrapper).
The salmon backed Target: Moon cards were not sold with gum by the way and that too is a story for another day!