Put this together over the holiday weekend. A twitter bot which represents the position of Jupiter's 4 largest moons in ASCII form
https://twitter.com/JupiterMoonPos
Originally created as an easy to access way to identify the moons during public observing sessions for my local astronomy club, the Perl code behind it is based on algorithms by Jean Meeus in his book “Astronomical Algorithms”.
As a happy accident, when you hold down the 'J' or 'K' keys, you get an animation of the moons orbiting.
I grabbed https://twitter.com/SaturnMoonPos and will do that next.