The King of the Planets Reigns Bright

Reflections of the Moon and Jupiter. Credit: John Chumack

Friday, October 28, is the date of opposition for the planet Jupiter. Opposition is a favorable observing time for planets because they are opposite the sun in our sky, rising as the sun sets and setting at sunrise, therefore being visible all night long. Jupiter will also be shining at its brightest during opposition, at magnitude -2.9.

Jupiter is found in the constellation Aries, close to the boundary of Pisces and Cetus. As the King of the Planets rises higher in the east, the notable Pleiades star cluster rises behind it in Taurus. Jupiter is easy to spot because it is so much brighter than any of the surrounding stars.

If you look at Jupiter through a telescope on Friday night, you will see the four largest moons scattered on either side of the planet. Ganymede, the largest satellite, is on the lower left, with Europa and Callisto extending outward to the upper right. Io is hiding behind Jupiter, but by late evening it will begin to appear from behind Jupiter’s limb on the same side as Ganymede.

Jupiter’s reign as the brightest visible planet currently in the night sky is chipped away little by little as Venus becomes more apparent. Venus is a bright magnitude -3.9, easily surpassing Jupiter and any other planet or star with its stunning light. But Venus is only just starting to peek out from the western horizon at sunset. On Saturday, October 29, while you may be shepherding your kids out trick-or-treating, see if you can spot Venus setting in the west while Jupiter rises in the east.

-- Kelly Kizer Whitt loves clean, clear, and dark skies. Kelly studied English and Astronomy at the University of Wisconsin-Madison and worked for Astronomy magazine. She writes the SkyGuide for AstronomyToday.com. You can follow her on Twitter attwitter.com/Astronomommy.