Home > Ephemeris Program, Jupiter > 01/09/2014 – Ephemeris – More on Jupiter’s Galilean moons.

01/09/2014 – Ephemeris – More on Jupiter’s Galilean moons.

January 9, 2014

Ephemeris for Thursday, January 9th.  The sun will rise at 8:18.  It’ll be up for 9 hours and 3 minutes, setting at 5:21.   The moon, 2 days past first quarter, will set at 3:20 tomorrow morning.

The planet Jupiter has, as of the latest count, 67 satellites or moons.  However only four can be seen in small to medium-sized telescopes.  Astronomers use the term moon and satellite interchangeably, though only moons orbit planets.  A satellite is a more generic term and is a smaller body that orbits another larger body.  Though we don’t usually call an artificial satellite orbiting the Earth a moon.  Anyway, the four bright moons of Jupiter are called the Galilean moons, because Galileo discovered then in early 1610.  Their names from Jupiter on out are Io, Europa, Ganymede and Callisto.  They orbit over Jupiter’s equator.  Since the planet has a very small axial tilt the moons seem to move back and forth from one side to the other of Jupiter in a nearly straight line.

Times are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.


Jupiter and moons

Jupiter and its four Galilean moons. The planet has to be over exposed to pick up the moons. But the eye can handle the brightness difference with no problem. This is one of my old pictures I do believe.

Jupiter eclipse

Jupiter with a solar eclipse in progress as Ganymede, lower left, casts its shadow on Jupiter on November 14, 2011 at about 10:15 p.m.. Credit: Scott Anttila.

The moon Io is off to the far left.  This eclipse can be simulated with Cartes du Ciel.


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