A Planetary Parade Appears Over Colorado

Boulder residents may have a chance to witness a beautiful sky event this week. Several planets are appearing along the same arc of the sky shortly after sunset, creating what astronomers often call a “planetary parade.”

While the planets are still millions of miles apart in space, their positions along the solar system’s orbital plane make them appear lined up from Earth’s perspective. Events like this always attract attention because they allow people to spot multiple planets in the same part of the evening sky.

Skywatchers in Boulder may be able to catch the alignment tonight and over the next several evenings this week, weather permitting.

Best Time to Look

The best viewing window is about 30 to 60 minutes after sunset, when the sky is dark enough for planets to appear but before the lowest ones dip below the horizon.

Look toward the western sky, low near the horizon.

During this time, several planets may be visible to the naked eye, including:

• Venus – the brightest planet in the evening sky
• Jupiter – another bright object that stands out clearly
• Mercury – faint and close to the horizon shortly after sunset
• Saturn – dimmer but sometimes visible in clear conditions

Two additional planets are part of the broader alignment but usually require equipment to see:

• Uranus, which can sometimes be spotted with binoculars
• Neptune, which requires a telescope

Even spotting two or three planets in the same area of sky can make for a memorable moment.

Where to Watch in Boulder

The key to viewing the planetary parade is having a clear western horizon. Locations with wide open views will give you the best chance.

Great spots around Boulder include:

• Flagstaff Mountain overlooks
• The NCAR viewpoint
• South Boulder Open Space
• Chautauqua Park fields

These areas provide expansive views of the sky and less interference from buildings or trees.

Why Planet Alignments Happen

Planetary alignments occur because all of the planets orbit the sun along roughly the same flat plane, known as the ecliptic. From Earth, this makes the planets appear along a curved path across the sky.

When several planets happen to occupy nearby positions along this path at the same time, they appear to form a loose line or arc. While smaller groupings happen regularly, seeing multiple planets visible during the same evening window is always exciting for skywatchers.

Boulder’s Perfect Skywatching Setting

Boulder’s elevation, dry climate, and nearby open space areas make it an excellent place for observing the night sky. On clear evenings, the thin mountain air often produces crisp views of stars, planets, and constellations.

With the Flatirons silhouetted against the fading twilight, even a quick look up can turn into a memorable moment.

Don’t Miss the Show

If skies remain clear this week, step outside shortly after sunset and look toward the western sky. You may spot several planets shining along the same stretch of sky, creating a rare planetary parade visible from Boulder.

Sometimes the most spectacular shows in Boulder aren’t on the trails or in the mountains — they’re happening far above us.

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