Rare “Conjunction” of the Moon and Three Planets

Star Walk
2 min readMar 8, 2021


The Moon, Mercury, Jupiter, and Saturn get close together

Very soon, you’ll have a chance to witness a beautiful alignment of the Moon, Mercury, Jupiter, and Saturn. In today’s article, we’ll tell you how to see this rare “quadruple conjunction”.

What is a conjunction?

In astronomy, a conjunction occurs when two сelestial bodies come close together in the sky, as seen from the Earth. In technical terms, for a conjunction to happen, the objects should share the same right ascension or ecliptic longitude.

Though it is terminologically incorrect, groupings of three and four celestial objects are often called “triple conjunctions” and “quadruple conjunctions”. For simplicity, we’ll also use the term “quadruple conjunction” in quotes.

How to see the “quadruple conjunction” in 2021?

From March 9 to March 11, the Moon, Mercury, Jupiter, and Saturn will gather in the constellation Capricornus. As a part of this massive grouping, three proper astronomical conjunctions will happen during these three days, so you will have a lot to observe.

First, a conjunction of the Moon and Saturn will occur on March 9, at 22:58 GMT. The 26-days-old Moon will pass 3°40' to the south of the ringed planet. The Moon will be shining at a magnitude of -10.4, and much dimmer Saturn will have a magnitude of 0.6.

Second, on March 10, the Moon will come close to Jupiter. The conjunction will take place at 15:37 GMT. The Moon will pass 4°02' to the south of Jupiter, shining at a magnitude of -9.9. The gas giant will have a magnitude of -2.0.

Finally, on March 11, at 01:02 GMT, a conjunction between the Moon and Mercury will happen. The Moon will pass 3°41' to the south of Mercury. The two space objects will have magnitudes of -9.6 and 0.0, respectively.

During all three conjunctions, the Moon and the planets will be easily visible to the naked eye on the sky’s dome. A pair of binoculars will allow you to see more details — for example, the four Galilean moons of Jupiter.

To spot the “quadruple conjunction” of the Moon and the planets in the sky, you can use our natural satellite as a guide. As soon as you find the Moon, look nearby to find Mercury, Jupiter, and Saturn. To identify all the three planets, use the Star Walk 2 app. Simply launch the app and point your device at the sky — you will see the name of any object your device is aimed at.

We wish you clear skies and happy observations!



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