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January 11: Psyche moves north of Aldebaran
Io transits Jupiter, showing us how quickly our view can change — now that we are a few days past opposition, the moon and its shadow won’t quite overlap, but instead Io’s shadow will now trail it across the planet’s cloud tops. (If you remember pre-opposition transits, such as Europa’s last week, the shadow previously began to transit before the moon that cast it.)
The transit begins late this evening, when Jupiter is still rising in the eastern sky for much of the U.S. Around 10 P.M. EST, Io is closing in on the planet’s eastern limb, with Ganymede much farther east. Europa and Callisto lie west of the planet, with the former closest to the gas giant.
Io’s transit begins around 10:40 P.M. EST. Its shadow is following close behind, beginning its own transit just four minutes later. By 10:50 P.M. EST, both moon and shadow are visible against the cloud tops near the eastern limb. It takes them about an hour to reach the center of the disk. A little more than an hour later, Io’s transit ends minutes before midnight in the Central time zone, with its shadow disappearing just a few minutes after midnight in the same time zone.
Sunrise: 7:21 A.M.
Sunset: 4:56 P.M.
Moonrise: 2:08 A.M.
Moonset: 12:01 P.M.
Moon Phase: Waning crescent (27%)
*Times for sunrise, sunset, moonrise, and moonset are given in local time from 40° N 90° W. The Moon’s illumination is given at 10 P.M. local time from the same location.
