Great Planet Parade: Will the rare seven-planet alignment be visible in SA? — What to know

Make a date with the night skies this Friday when all seven planets in our solar system will briefly align in what astronomers refer to as the “Great Planet Parade”.

During this rare celestial phenomenon that will only occur again in 15 years’ time in 2040, Saturn, Mercury, Neptune, Venus, Uranus, Jupiter and Mars will all appear simultaneously in the sky.

The planetary alignment already started taking shape in January, with this week marking the grand finale when Mercury, which orbits closest to the Sun, will join the “parade”.

Planet parade: What to know about February’s must-see astronomical event

The good news is that the magnificent cosmic spectacle will be visible across the globe, including in South Africa.

 According to the National Aeronautics and Space Administration (Nasa), four of the planets — Mercury, Venus, Jupiter, and Mars — will be visible to the naked eye with clear skies. Saturn will be harder to see because it will be low on the horizon.

 Space.com advises you will need a telescope to spot the other two planets — Uranus and Neptune.

Tips for best viewing experience

The display will only be visible for a few minutes just after sunset because the planets near the horizon — Saturn and Mercury — will be setting.

Once they drop below the horizon, they will no longer be visible, but the other planets will still linger in the night sky.

• The ideal time to witness the planetary alignment is about 45 minutes after sunset.
• For the best view, head to a location away from city lights with a clear view of the horizon.
• Look towards the southwest to get the best chance to see the parade.
• Make sure you’re looking at the planets and not the stars! It may be easy to distinguish Venus because it will be the brightest celestial object after the Moon in the sky. The other planets, however, are a little fainter. One of the differences is that planets, unlike stars, don’t twinkle. 

If you are curious about whether you will be able to see the planet parade this Friday from where you live, use the “Time Machine” feature in the free Star Walk 2 app to see how the planets will look from your location on the given date. 

Free app makes planet-spotting easy

1. Open Star Walk 2 and go to the Planets section from the Menu.
2. Tap “Planet Walk”.

• You’ll see a sky map with planets highlighted.
• Planet icons (along with the sun and moon) appear at the bottom. Tap one to see its location on the map.
• If a planet is below the horizon, its icon will look faded.

3. Point your device at the sky to match the image on your screen with the real sky.
4. Tap a planet’s icon and follow the white arrow to spot it in the sky.

What is a planetary alignment?

The planets in our solar system orbit the sun essentially along the same line across the sky in a plane called the ecliptic.

For that reason, planets in our Earthly sky always appear somewhere along a flat, disc-shaped plane, according to EarthSky, a website dedicated to cosmic news.

The ecliptic is also the reason that we on Earth sometimes observe planets appearing to approach closely to each other in the sky “while they careen around the cosmic racetrack,” according to Nasa.

“We see the racetrack of the planets from the perspective of one of the racers ourselves,” Preston Dyches, who hosts Nasa’s What’s Up, a monthly video series that describes what’s happening in the night sky, wrote for Nasa. “When viewed edge-on, this disc appears as a line.”

Whenever planets become visible, these events are often referred to as planetary alignments.

When will the next planetary alignment take place? 

Line-ups of four or five planets occur every few years, according to Nasa.

In late August 2025, four planets will be visible before sunrise, and in late October 2028, five planets will be visible at once before sunrise. Another five-planet alignment will occur in late February 2034, with the planets visible after sunset. 

“In summary, while they aren’t once-in-a-lifetime events, planetary parades afford an uncommon opportunity to look up and appreciate our place in our solar system, with diverse worlds arrayed across the sky before our very eyes,” Nasa says on its website. 

Outside of the planetary alignments, it’s possible to spot other planets individually. Mars, Jupiter and Saturn are frequently seen in the night sky, according to Nasa. 

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