Call for observation: Jupiter's moons naked eye on January 5, 2014?

I just read this Call for Observation by distinguished planet observer Bernd Gährken: The opposition of Jupiter of January 5, 2014, is a rather unusual one, because seen from the distant planet, Earth will transit the sun's disk. Therefore, the phase angle will be extremely small and the opposition effect on it's moons will be unusually strong.

The jovian moons therefore should appear 30% brighter than usual. Adding to this, all moons will be lined up on the planet's western (preceding) side and Ganymede (III), the biggest and brightest of them, is at it's maximum elongation.

Simulation of the Jupiter system for Jan 5, 2014, 22:14 CET (21:14 UTC)
With the (our own) moon setting at 22:00 CET, chances are very good to see the jovian moons with the unaided eye. Position yourself in such a way that the bright planet is hidden by a building, roof, etc., and it should work! There won't be a better chance to do this in our lifetime!

Opposition is exactly at 21:11 UTC. Jupiter is 4.2 AU (630 million km) from Earth at opposition, -2.7mag bright, and appears 46.76" in diameter in a telescope. It is visible as a bright star all night in the constellation Gemini

I personally am interested in any (positive or negative) results, and Bernd is as well. You're invited to report them as a comment, if you like, or mail them to Bernd.

Update: I took this picture (0,5s @1600ASA, f/5,6, 200m telephoto lens) almost exactly at opposition. The moons (Io, Europa, Ganymede and Callisto, as well as 44Gem) are easy in binoculars (10x50), but I could not see any of them with unaided eyes. Maybe one needs better (darker) skies..?


  1. Jupiter observation. January 5, 2014, 11:25 PM CST (-6 h UT).

    Little Falls, MN USA. 45° 57' 55" N; 94° 22' 8" W.

    Current Weather Conditions:
    Fair -24°F.
    Humidity 55%
    Wind Speed NW 10 mph
    Dewpoint -35°F. (-37°C.)
    Wind Chill -46°F. (-43°C.)
    Visibility 10.00 mi

    Jupiter Observation:
    To the naked eye, 20/20 corrected eyeglasses vision, Jupiter appears as a bright orangish dot. There appears to be a smaller pin point of bluish light to the right at about 2 o'clock.

    Using a pair of Bushnell 7x50 Sportview binoculars, Jupiter is a very bright whitish-orange dot. There is a distinctively bluish pin point of light to the right of Jupiter at approx. 2 o'clock.


  2. Thanks JS for your report! So far, I collected 14 negative reports from Germany (including my own) and only one positive. Seems the task was much harder than I thought. It required really dark skies and good seeing. Maybe with time, more positive reports show up.