Planetary Conjunctions: What Are They and When Is the Next One?

~4 min

In this article, you’ll learn when the planets will meet in the sky and how to quickly identify them using the free stargazing app Sky Tonight.


What is planetary conjunction?

In simple words, a planetary conjunction occurs when two or more planets appear close to each other in the sky. Such proximity of planets is an optical illusion — in reality, they are very far away from each other.

From an astronomical point of view, a conjunction happens when celestial objects share the same right ascension¹ or ecliptic longitude² in the sky.

¹Right ascension is the equivalent of longitude on the Earth’s surface projected onto the celestial sphere.

²Ecliptic is an imaginary line that marks the Sun’s apparent path across the sky during a year. Ecliptic longitude is measured along the ecliptic eastwards from the Sun’s position at the March equinox.

While the first definition is more common, it isn’t very precise. In fact, it describes a close approach (small angular separation) of space objects — an event that usually takes place near a conjunction. But don’t confuse these events! A close approach isn’t necessarily a conjunction.

Usually, the distance between objects during a conjunction varies from 0.5° to 9°. To get it better, imagine that 0.5° is the average width of a Full Moon disk. Sometimes planets come even closer — last time it happened with Jupiter and Saturn in 2020 when they appeared less than 0.1° apart. Such an event is called the Great Conjunction and provides a spectacular show for stargazers.

A conjunction can include other celestial objects besides planets — for example, moons, asteroids, or stars. In our article, we list the upcoming conjunctions of the Moon and planets, so you can learn which planet is close to the Moon tonight.

Planetary alignment

Some people confuse a planetary conjunction and a planetary alignment, sometimes referred to as a “planet parade.” A conjunction implies a shorter than usual distance between objects in the sky, while an alignment means that planets line up in a row in the same area of the sky, as seen from the Earth.

Locating planets with Sky Tonight

You can easily locate planets in the sky above you with the help of Sky Tonight. Just follow these steps:

  • Launch the app and type the name of the planet you're looking for in the search bar.
  • Tap the blue target button next to the relevant result, and the app will show you the planet's location on the sky map.
  • Tap the blue compass button to find the planet's actual position in the sky above you. A white arrow will appear on your screen, so you can follow it until you spot the planet. The app's image matches the real sky.

Upcoming conjunctions

May 31, 2024: Mercury-Uranus

On May 31, at 01:24 GMT (May 30, 9:24 p.m. ET), Mercury (mag -0.8) will pass 1°21' from Uranus (mag 5.8) in the constellation Taurus. The planets will be above the eastern horizon in the morning. This conjunction will be difficult to see from either hemisphere, as the planets will be obscured by sunlight. Also, Uranus isn't visible to the naked eye and requires optics.

June 4, 2024: Jupiter-Mercury

On June 4, at 10:04 GMT (06:04 a.m. ET), Jupiter (mag -2.0) will pass 7'04" from Mercury (mag -1.2) in the constellation Taurus. Unfortunately, the conjunction will be difficult to see from most locations because the planets will be too close to the Sun. You can try your luck and look for them low over the northeastern horizon in the morning. Use the Sky Tonight app to find the planets in the sky.

July 15, 2024: Mars-Uranus

On July 15 at 09:22 GMT (05:22 a.m. ET), Mars (mag 0.9) will pass very close (0°33') to Uranus (mag 5.8) in the constellation Taurus. From the Northern Hemisphere, the planets will be visible high above the eastern horizon in the morning, about an hour before sunrise. From the Southern Hemisphere, they will be a little lower, in the northeastern direction. You'll need at least a pair of binoculars to see Uranus.

August 7, 2024: Mercury-Venus

On August 7, at 17:23 GMT (1:23 p.m. ET), Mercury (mag 1.8) will pass 5°42' from Venus (mag -3.8). Venus will be in the constellation Leo, while Mercury will be on the border of Leo and the small constellation Sextans. Because the planets will be close to the Sun, they will be difficult to observe. You can try to see them in the evening, low in the west.

August 14, 2024: Mars-Jupiter

On August 14, at 14:45 GMT (10:45 a.m. ET), reddish Mars (mag 0.8) will pass just 0°18' from bright Jupiter (mag -2.2). This beautiful duo will be visible to the naked eye in the constellation Taurus. Considering the brightness of both planets, the distance between them, and their visibility, this conjunction can be considered the best of the year. From the Northern Hemisphere, Mars and Jupiter will be visible from about midnight until morning, rising high above the eastern horizon. In the Southern Hemisphere, the planets will rise in the northeast in the morning, a few hours before sunrise.

Now you know how and when to spot the planets close together. If you enjoyed this article, share it with your friends.

We wish you clear skies and happy observations!