ok , now we want to start the main point , but before that , let's talk about the history of sketching. we can see sketches of the moon, Mars or Saturn from scientists like Galileo, Lowell, Huygens, Cassini. Most of these scientists weren’t artists, and their sketches often weren’t pretty as you can see below (I mean their work are not artistic masterpiece) , but they are really valuable! and the early astronomers traded their sketches, and compared what they saw while they tried to understand it
and the other point is: these astronomers did their sketches just by pencil and paper and we can do it like that ,too (although we have sybersketching (by tablet or sth) , but I mean we don't need special equipment for drawing and it also can be easier from photography
these are galileo's sketches from the moon and jupiter with its moons (with this sketches he find out that they turn around jupiter and not earth)i