The Pioneer 10 Spacecraft launched in 1972 was the first object ever built that could achieve escape-velocity to exit the Solar System.
A ‘Pioneer Plaque’ was installed on it that included examples of what the designers felt were representative of the ‘Human’ and of ‘Planet Earth’.
It had Digital-Codes, equations from Chemical interactions and Astrophysical elements. And it had an [almost naked] figure of a Man and a Woman.
A stretched hand in greetings to all out there. But it is unlikely that the designers actually thought that any of this would be understood by an alien intelligence. For this whole notion of ‘Understanding’ and ‘Communication’ as we understand it and communicate it is a very human idea.
Or as Ludwig Wittgenstein summarily put it: ‘Die Grenzen meiner Sprache bedeuten die Grenzen meiner Welt’ [The limits of my language stand for the limits of my world.]
We have no reason to believe [perhaps they do] that aliens exist as anything we can understand or communicate with, whether these images and words have any meaning at all in this context.
Perhaps the Aliens are blips of erratic light that laugh a great deal more than we humans do [‘light’ and ‘laugh’ still being very human points of recognition].
But you don’t need to go to outer-space to appreciate this point. Travel, right here on this our splendid earth with its 6900 distinct languages will open you up.
But the biggest controversy over this plaque arose because the human figures were drawn near-naked. The blips of light might get aroused and that would not be a good thing [they were redrawn]. Only in America!