This month marks an excellent opportunity to explore the majesty of Jupiter. On December 7th, the fifth planet will be at opposition, its closest point to Earth, putting on a dazzling display for stargazers. Four bright moons – Ganymede, Callisto, Io, and Europa – will also be in action, creating breathtaking events such as transits, occultations, eclipses, and shadow transits.
One of the most spectacular events occurs when a moon passes behind Jupiter, temporarily disappearing from view. On December 8th, witness Io’s white dot vanish at 1:49 a.m. EST before reappearing at 4:01 a.m. EST. The Great Red Spot will be invisible during this event, allowing you to observe the vibrant cloud bands instead.
Another notable occurrence is an eclipse, where a moon passes into or out of Jupiter’s shadow. On February 1st, Io emerges from Jupiter’s shadow about half a planet-width away, creating a rare and awe-inspiring sight.
Shadow transits are particularly captivating, as they involve the shadow cast by a moon onto Jupiter’s clouds. Near opposition, this shadow appears close to the moon itself, making for an impressive observation.
For optimal viewing, a telescope is recommended due to the moons’ relatively small size. Binoculars with 7x magnification can also reveal some details. To enhance your observing experience, check out programs like Galileo’s TOES or visit shallowsky.com/jupiter for predictions and animations of these events.
Source: https://www.astronomy.com/observing/examining-galileos-toes