The planet Jupiter is disappearing from the evening sky. And tomorrow, it’ll briefly disappear from the daytime sky — but only along a narrow path across the southern hemisphere.

Jupiter is quite low in the west as night falls, so you need a clear horizon to spot it. It looks like a bright star shining through the twilight. It’s far below much brighter Venus, the “evening star.” Jupiter sets about the time the sky gets fully dark.

Jupiter is vanishing from the evening sky because of our changing perspective. It’s about to pass “behind” the Sun, so it’ll be hidden in the Sun’s glare. It’ll return to view — in the morning sky — in a couple of months.

For tomorrow’s daytime disappearance, Jupiter will be hidden by the Moon — an act called an occultation. It happens because both Jupiter and the Moon stay close to the ecliptic — the Sun’s path across the sky. They both stray from it a little bit, so most months the Moon passes right by Jupiter. When the alignment is just right, though, it passes in front of the giant planet, hiding it from view.

This occultation takes place during the daylight, so it’s visible only through a telescope — and only along a path through north and central South America and the southern Pacific Ocean.

Tomorrow evening, though, the Moon and Jupiter will stage a nice encounter. They’ll stand side by side in early evening — the crescent Moon and the “disappearing” planet Jupiter.
 

Script by Damond Benningfield

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