In the early hours of Saturday, June 17, 2023 an alignment of Saturn, Neptune, Jupiter, Uranus and Mercury will be visible in the eastern night sky.
All five planets will be spread out along the ecliptic—the plane of the solar system upon which all planets orbit closely to.
Be outside looking east at around 5:00 a.m. and you’ll see Jupiter shining brightly, with Saturn high in the southeast.
“While Jupiter and Saturn will be easy to spot by eye, Mercury will be more challenging as its proximity to the sun means that it is only just above the horizon and visible about an hour before sunrise—and the sky could be brightening then,” said Professor Don Pollacco, an exoplanet expert at the Department of Physics at the University of Warwick in the UK, in an email.
Mercury rising
You’ll also need a good view low to the eastern horizon to catch Mercury—trees or buildings could easily get in the way. A second or third floor is recommended, as is an east-facing coastal location.
The key is to find out the time Mercury will rise in your location—the final planet of the five to appear. That time—which you can find out using any stargazing app or by visiting Stellarium Web Online Star Map and pressing ‘Planets Tonight’—should signal the last phase of your observing.
Grab some binoculars
Before Mercury rises you will easily have found Jupiter and Saturn and can spend the time looking for Neptune and Uranus. “Neptune and Uranus need binoculars to be sure of seeing them, although some keen-sighted people can see Uranus unaided,” said Pollacco.
“Jupiter and Saturn will be bright objects that have a yellowy colour, Mercury often looks pink, and Uranus and Neptune pale white/green,” he added.
Planet-clusters
The five-planet line-up is the result of all the planets traveling around the solar system at different speeds, with causes apparent clusters of planets as seen from Earth.
“Planetary alignments have always occurred—they are times when the planets in the solar system are all roughly positioned in the same direction when viewed from Earth,” said Pollacco. “Given that we understand the orbits of the planets we can predict when these alignments will occur.”
While the planets may look relatively close together in the sky they are of course separated by many millions of miles.
Alignments coming up
From sunset on July 19, 2023 and for a few evenings afterwards it will be possible to watch the three other rocky planets—Mercury, Venus and Mars—in the western sky.
The next “golden conjunction” will take place on Sept. 8, 2040, when Mars, Mercury, Venus, Saturn and Jupiter will be visible in the same 10º area of the night sky right after sunset in the west.
Wishing you clear skies and wide eyes.
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