Planetary Conjunctions: What Are They and When Is the Next One?
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.
Contents
- What is planetary conjunction?
- Planetary alignment
- Locating planets with Sky Tonight
- Upcoming conjunctions
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
January 19, 2025: Saturn-Venus
On January 19, at 01:26 GMT (January 18, 08:26 p.m. EST), Saturn (mag 1.1) will pass 2°12' from Venus (mag -4.6). Both planets will be bright enough to be seen with the naked eye. Look for them in the evening, about an hour after sunset. Venus and Saturn will be in the constellation Aquarius, above the western/southwestern horizon for the Northern Hemisphere and just above the western/northwestern horizon for the Southern Hemisphere.
February 1, 2025: Neptune-Venus
On February 1, at 16:33 GMT (11:33 a.m. EST), Neptune (mag 7.9) and Venus (mag -4.8) will be at a distance of -3°19' from each other in the constellation Pisces. A thin crescent Moon will join them and even pass between the planets at some locations. Look for them in the evening, when the sky gets dark. While Venus will be bright enough to be seen with the naked eye, faint Neptune will require a small telescope or at least binoculars. To locate Neptune near Venus in the sky, use the free astronomy app Sky Tonight.
February 25, 2025: Saturn-Mercury
On February 25, at 12:02 GMT (07:02 a.m. EST), Saturn (mag 1.1) will pass 1°27' from Mercury (mag -1.2). Technically, both planets are bright enough to be visible to the naked eye, but at this period, they will be too close to the Sun to be seen in its glare.
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!
