Amadeo astronauta. written and illustrated by Juan Ferrándiz. Barcelona : Edigraf. 16 p. ; 25 cm. 1963
I think it was first published in 1958 by Vilcar. So this is probably the 3rd edition.
A Spanish children's book from Madrid. It seems to have been reprinted several times. While fictional, the "astrofuturistic" or "retrofuturism" painted illustrations are something to see. It is the same old story of an Uncle who builds a rocket.
For the full text in Spanish see here: http://electrogermen.blogspot.com/2010/12/amadeo-astronauta.html
I tried to use Google Translate to get the text on this first page (but didn't have the patience to do them all).
But the story seems pretty clear from the illustrations.
They have been watching us and are worried about our atomic tests.
We are the only planet not part of our Solar System's "Congress"
You can not help but love the modernist architecture of their homes.