This is a photo I took 13 years ago of Jupiter and 4 of its moons (top). As a reference the image below is the simulated position at that same time.
#Jupiter #Astronomy #Astrophotography #Space
QT: https://jeffreyfreeman.me/photography/jupiter-moons/
@freemo Incredible how sailors used the moons to find longitude with such primitive kit, ain't it.
@freemo Once they had clocks that kept the time at home, they could tell their longitude at midday.