Two planets in the same place in the sky, or nearly: they merge.
The strongest aspect and the least predictable, because the outcome depends on which planets are involved: Venus and Jupiter together give pleasant expansion, Mars and Saturn a dull tension. It is neither good nor bad in itself — it amplifies.
How to read a conjunction in your chart
In a conjunction, two functions of the personality work as one: you cannot switch on one without the other. With Mercury and Saturn together, for instance, thinking tends to be careful and structured, as if every idea had to pass an inspection before it is spoken.
Three questions help. Which planets are involved? Which sign does the conjunction fall in, since the sign sets their shared tone? Which house, meaning which area of life it plays out in? Then look at the orb: within a couple of degrees the merger is almost complete, while towards 8° the two planets keep more of their independence.
Rare conjunctions and monthly ones
Not every conjunction carries the same weight. The Sun and Moon meet every month, at the New Moon. People born around then have both lights, as tradition calls the Sun and Moon, in the same place, often read as a personality focused in a single direction. Jupiter and Saturn, by contrast, meet roughly every twenty years, and the slower outer planets even more rarely. A whole generation shares those conjunctions, so they are read more as a collective climate than as a personal trait.
When three or more planets gather in the same sign or house, astrologers call it a stellium: one area of the chart holding a great deal of its energy.
Frequently asked questions
Is a conjunction a good or bad aspect?
Neither. A conjunction joins and amplifies, and the result depends on the planets. The Moon with Neptune is traditionally read as sensitivity and imagination, but also as softer emotional boundaries. Even a demanding conjunction describes a concentrated resource, one you can learn to use over time.
What does it mean to have a planet conjunct the Sun?
That planet merges with your sense of identity and expresses itself through it: Mercury close to the Sun, for example, ties thinking tightly to self-image. An old tradition calls a planet too close to the Sun "combust", as if outshone by it. Mercury and Venus never stray far from the Sun, so they are often found in this position.
What does a transiting conjunction to a natal planet mean?
It is the most direct kind of transit: a planet in today's sky passes over a point in your chart and brings its themes to life. In astrology it is read as a time of beginnings or intensity. The best-known case is the Saturn return, around 29 or 30, when Saturn comes back to where it was at your birth and is traditionally seen as a time for taking stock.
See it in your own chart
Calculating your birth chart is free: wheel, planets, houses, aspects and a first reading. All you need is your date, time and place of birth.