What is a planetary alignment, and can you see it?

A planetary alignment, also called a planet parade, is when several planets are above the horizon at the same time, strung along one arc of sky. They don’t form a straight line in space, and you won’t see a dramatic row of discs. What you can see is a few bright points sharing the sky, often with the Moon nearby.

Why they line up at all

All the planets orbit the Sun in roughly the same flat plane. From Earth that plane appears as a band across the sky called the ecliptic, the same path the Sun and Moon follow. So planets always appear along that band, and “alignment” means several of them happen to be on our side of the sky together.

What to expect

• Brightness: Venus and Jupiter are unmistakable. Mars and Saturn are easy. Mercury is low and brief.
• Shape: an arc stretching across much of the sky, not a cluster.
• Faint ones: headlines often count Uranus and Neptune. You need binoculars or a telescope for those.
• Timing: often before dawn or soon after sunset, when some planets sit low.

How to check a date

1. Look up the event in a reliable calendar for your location.
2. Check what time each planet rises or sets where you are. Headlines are often written for one time zone.
3. Find a spot with a low, open horizon in the direction the planets are.

Sky Map (my app) has an astronomical calendar that includes planetary alignments alongside meteor showers and eclipses, and a planet visibility timeline for each night. In the live AR view the planets are labelled along the ecliptic.

Related: what planets are visible tonight, Mercury, Uranus and Neptune and the Sky Map guides.