Deluxe Golden Book: The World of Science...1965.
I must have read the Astronomy chapter hundreds of times: "If the earth were the size of a quarter dollar (my mum told me that was about the same size as a shilling...decimal currency had not yet arrived ) the Sun would be a 9 foot ball, 1000 feet away.....
This helped me understand how mind-bogglingly big space really is.
I suspect Douglas Adams read the same book.
Bugger...feeling a little ancient