[ETL]

Here is a page that shows the positions of the largest 4 moons of Jupiter at any time. It’s very cool to watch through a telescope since the moons travel so fast you can often see them orbiting if one passes another or occults or eclipses.

You never actually 'see' them moving. It can take many minutes to detect the slightest change in position.

[zeebee]

Au contraire, you can see them moving.

When one is in front moving to the east and another is behind moving to the west and they cross, you can easily watch the distance change.

Some of the moons orbit in less than 2 days (unlike ours which takes a month).