June Planetary Parade

What a spring it has been for skywatchers! First, millions saw a rare total solar eclipse that crossed parts of North America, followed by an extremely rare G5 geomagnetic storm that produced aurorae as far south as Alabama, Texas, and California. Just over a week later, a super-rare green-blue meteor lit up the sky across Portugal and Spain. So, what’s next on the agenda? In the pre-dawn skies on June 3 and 4, six planets—and a waning Moon for good measure— will appear on one side of the Sun, forming a “planetary parade” across the sky before sunrise. It sounds intriguing, but will this planetary alignment be as sensational as the other must-see celestial events earlier this year? Let’s look closer and learn more.

What is a planetary parade?

A planetary parade occurs when our Solar System’s planets appear to line up at the same ascension level in the night sky, as seen from Earth. They don’t really create a perfect line in our Solar System; each planet’s orbital plane causes the illusion. Three-planet parades are quite common and occur about twice a year. The more planets in the parade, the rarer it is.

There are different types of planetary parades:

Classification of Planetary Parade	Number of Planets	How Rare?
Mini	3 planets	Twice a year
Small	4 planets	Once a year
Large	5 or 6 planets	Every 19 years
Great	9 objects (may include Pluto)	Once in about 170 years

 

What will you see (and not see)?

When envisioning a six-planet parade, you might picture a dazzling string of six naked-eye planets spanning the sky, complemented by a silvery Moon. But while this alignment is indeed rare and special, it will look very different to everyday observers.

Remember, the planets’ magnitudes all differ. The outer planets in the parade, Uranus and Neptune, are too dim to see with the naked eye and are only visible in a telescope while the sky is still dark. You might see them early during the parade in a very large telescope.

Meanwhile, the planets closest to the Sun—Jupiter and Mercury—could be easily lost in the pre-dawn sky glow since they will appear low to the horizon. (Please refrain from attempting to look for any object near the Sun, as permanent damage to your eyes may occur.)

That leaves only Mars and Saturn remaining, visible to the naked eye. So, if you are an earlier riser, you can expect to see a thin crescent Moon near reddish Mars in the eastern sky with Saturn further down the line. It will be a nice view, and you can look closer at many of the planets in your telescope. But the more thrilling part of viewing this spectacle is soaking in the knowledge that six planets are in rare alignment, even though you can’t see them all with your naked eye.

The planets will continue their gradual motion across the sky in the days and weeks after the six-planet alignment. On June 29, you’ll have an even better opportunity for a picturesque view! A 43% waning Moon will be positioned nicely between Mars and Saturn. Jupiter will have moved further away from the Sun, making it easier to spot as it joins Mars, Saturn, and the Moon in the morning twilight. So, while you may only see three objects (the Moon, Mars, and Saturn) on June 3 and 4, you’ll see four objects (with the addition of Jupiter) on June 29—all naked-eye visible!

While June’s planetary parade won’t be as spectacular as a total solar eclipse or the northern lights, it’s still a rare and interesting phenomenon to check off your astronomer’s bucket list. And it’s just a matter of time before another cosmic event graces our skies, like a planetary conjunction, a planetary opposition, a bright meteor shower, a naked-eye comet, or even a total lunar eclipse. Keep looking up, and clear skies!