Question: In 19th century texts on astronomy, the planets are often represented by [symbols](http://en.wikipedia.org/wiki/Astronomical_symbols): ☿ for Mercury, ♀ for Venus, etc..

Did NASA ever use these symbols, or were they already obsolete by then? If they did use them, I'd expect it to be very early on.

Answer: 
They have absolutely used these, in various mission badges:

This was the logo for the Mercury project:

![](https://history.nasa.gov/project_mercury.jpg)

Here's a patch from the Viking program:

[![](https://i.stack.imgur.com/fi1mO.jpg)](https://i.stack.imgur.com/fi1mO.jpg)  

(source: [colostate.edu](http://rammb.cira.colostate.edu/dev/hillger/Viking_mission-patch.jpg)) 

And one from Mariner 2, to Venus:

[![](https://www.spacecollection.info/patches/mariner_2_patch.jpg)](https://www.spacecollection.info/patches/mariner_2_patch.jpg)

None of these are for any sort of technical reason; I'm sure the symbols aren't used for anything important, but as a little bit of astronomical history, they're not completely forgotten, either.
Mariner Jupiter Saturn, later named Project Voyager, initially had the Jupiter and Saturn symbols on the project logo.![enter image description here](https://i.stack.imgur.com/adimi.jpg)