Rare planetary lineup on June mornings

June features an unusual planetary lineup with all 5 bright planets lying in order from the sun in the morning sky. Mercury hugs the morning horizon (starting around June 10), then brilliant Venus, followed by red Mars, bright Jupiter, and finally, Saturn. And don’t forget a 6th planet: the one you are standing on, Earth! You’ll be able to see all 5 planets with the unaided eye until Mercury slips away in the morning twilight in early July. Chart via John Jardine Goss.

If you’ve never seen all the bright planets at once, June is your perfect chance. The five brightest planets – Mercury, Venus, Mars, Jupiter and Saturn – are lined up before dawn. They stretch across the sky from the east-northeastern horizon to above the southern horizon. And if you have patience and binoculars, you can hunt down the two challenging planets – Uranus and Neptune – that are hiding among the classical planets.

Planetary lineup before dawn

Start looking in mid-June when Mercury makes an appearance above the eastern horizon. The innermost planet is heading toward greatest western elongation, when it’s farthest from the sun in the morning sky, on June 16.

This is the view from the Northern Hemisphere when Mercury reaches greatest western elongation – its greatest angular distance from the sun – on June 16. You can find it in the morning sky hugging the horizon to the lower left of the much brighter Venus. The beautiful Pleiades star cluster is also nearby. Chart via John Jardine Goss.

In the Southern Hemisphere, Mercury lies between bright Venus and the east-northeastern horizon before sunrise during the 2nd half of June. The bright reddish star shining between the 2 planets is Aldebaran in Taurus the Bull. The beautiful Pleiades star cluster is also nearby. Chart via John Jardine Goss.

The moon passes the lineup of planets

If you’re not familiar with which bright spot of light is which planet, the moon can be your tour guide. Follow it in June as it passes Saturn on the 18th, Jupiter on the 21st, Mars on the 22nd, Venus on the 26th and Mercury on the 27th. Notice also how the phase of the moon changes, narrowing as it moves toward new moon.

In the early morning hours of June 18, the waning gibbous moon lies near Saturn. The bright star close to them is Fomalhaut, a favorite in the fall evening sky. Chart via John Jardine Goss.

The last quarter moon glows close to Jupiter on the morning of June 21. Chart via John Jardine Goss.

On the morning of June 22, the waning crescent moon glows near red Mars in the morning sky.

The waning crescent moon, complete with earthshine, lies to the right of Venus on the morning of June 25. The delicate Pleiades twinkles above them. The following morning, the moon moves immediately to the left of Venus. Mercury is to their lower left, just above the horizon. Chart via John Jardine Goss.

By June 27, the thin waning crescent moon lies very close to the horizon and left of Mercury. Bright Venus shines to their upper right in the morning sky with the delicate Pleiades twinkling above them.

5 bright planets shifting apart

Notice how the planets shift from June 10, when Mercury first appears, to the end of the month. While they stay in order, the space between them expands. Mars and Jupiter were particularly close, coming off a conjunction at the end of May. They’ll continue to separate throughout June.

At the beginning of the event, the lineup of the five planets stretched 92 degrees across, taking up about half the sky. By June 30, the distance between first and last planets in the lineup, Mercury and Saturn, will have grown to 116 degrees. Most the planets will retain a similar brightness throughout June, but Mercury will slowly brighten each morning. Mercury grows brighter as it edges ever nearer to the sun, which is what will bring this lineup of 5 planets to an end. Eventually, Mercury will be too close to the sun to escape the dawn’s light.

Uranus and Neptune

If you want to spot Uranus and Neptune, you’re going to need a little help. A good star chart and a pair of binoculars should do the trick. Try Stellarium to find the locations of Uranus and Neptune on the nights you wish to observe.

Uranus, the brighter of the two, starts June closer to the horizon than Venus but ends the month higher in the sky than Venus. Your best bet to find Uranus is when it passes Venus around June 11. From the Northern Hemisphere, Uranus will be to the upper left of Venus, about three full-moon widths away. On June 12, Venus is about the same distance from Uranus but now almost directly below it.

Neptune doesn’t have anything as handy as a bright planet passing by to help you track it down. (That opportunity was on May 18 when Mars passed less than a half degree below Neptune.) Neptune is between Jupiter and Saturn, though much closer to Jupiter. It lies below the circlet of Pisces. You can find it on a star chart and then hop your way to it.

The path of the ecliptic

Now, if you know that the planets all trace the same path – called the ecliptic – because they’re all in the same plane of our solar system, you’ll know that the planets are all essentially “in a lineup” all the time. It’s just that most of the time the planets aren’t close enough together for you to easily distinguish that line. Oftentimes, some planets will be in the morning sky while others are in the evening sky, so not all planets are visible above the horizon at the same time.

Take advantage of this special opportunity in June to see them all lined up together across the morning sky.

Bottom line: You can spot a planetary lineup all through June. Look in the morning before sunrise for the five brightest planets stretching from the east-northeast toward the south.

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