The Galilean satellites of Jupiter

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h m s

(as in inverting telescope)

(as in diagonal prism/mirror)

(not inverted or flipped)


Hourly animation can be done by selecting the arrow for incrementing hours and then pressing the Enter key or even holding it down so it repeats.

The calculation scheme is from Jean Meeus: "Astronomical Algorithms", 2nd edition (corrected August 2009), Willmann-Bell Inc. The lower accuracy scheme of the two given in chapter 44 is used. This is accurate enough to show the layout on a given date but not accurate enough to show whether the satellites occult or eclipse each other.

Additional material for Handbook 2014

By autumn 2014 the equatorial plane of Jupiter becomes sufficiently aligned with the Earth that mutual occultations and eclipses between the Galilean satellites start to become visible:

Additional material for Handbook 2015

The Galilean satellites continue to be visible until the end of July: