Why do they break every rule you live by?

Are Capricorn and Aquarius compatible?

Capricorn and Aquarius are a semi-sextile: earth and air, cardinal and fixed, one sign apart on the zodiac wheel. It is not one of Ptolemy’s five classical aspects; astrologers call it a minor angle. But that compares two Suns and nothing else. Venus, Mars, the Moon and the descendant decide how it actually feels.

You're here because of someone.

The Sun signs say not quite. Two whole charts say far more.

Your card is worked out from the day, the minute and the place you were born, not from a sign you share with a twelfth of the planet.

Every Capricorn and every Aquarius reads this page. Only your card knows you.

Find out your true compatibility.

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Admit one Capricorn Earth · Cardinal Dec 22 – Jan 19

Admit one Aquarius Air · Fixed Jan 20 – Feb 18

⚺︎ Semi-sextile · 30°Earth + air · cardinal + fixedA minor aspect, added long after Ptolemy

What it is: synastry, the art of comparing two charts

Comparing two people's charts has a name: synastry. Astrologers lay one chart over the other and look at the angles between the two sets of planets, the same angles the old books use inside a single chart.

Sun-sign compatibility is the shortcut version. It compares only the two Suns, and the angle between them is the aspect: four signs apart is a trine, two apart a sextile, three apart a square, six apart an opposition. Ptolemy called the trine and the sextile harmonious, and the square and the opposition disharmonious. ¹

Elements describe temperament (fire, earth, air, water) and modes describe pace (cardinal starts, fixed holds, mutable adapts). A pair can share one, both or neither. Capricorn and Aquarius share neither.

Full synastry goes much further: whose Venus lands on whose Moon, where one person's planets fall in the other's houses, how the two descendants line up. Ptolemy himself compared the Sun and the Moon of both charts, not just the Suns. That is why the same Capricorn can get on beautifully with one Aquarius and not at all with another. ²

Why do Capricorn and Aquarius feel so close and so far apart?

The traditional portrait: the same for every Capricorn and every Aquarius.

Capricorn in love

Capricorn, traditionally, courts the way it builds a career: slowly, seriously and with a plan. The old books say a Goat shows love through reliability, the bills paid and the promise kept, and gets warmer with time, not cooler. Behind the dry humour is a lot of feeling. Don't expect it on the first date.

Aquarius in love

Aquarius, in the old portrait, falls in love with a mind. Friendship first, often for years, then something more, on its own terms. Traditionally an Aquarius needs space, honesty and a partner with ideas of their own, and has no patience for jealousy or rules made for the sake of it. Try to own one and it leaves the room, politely.

Together

Air and earth. Air redraws the map halfway there; earth packed the snacks last night. Tradition calls it the idea meeting the plan. Who's holding the map?

Cardinal meets fixed. One starts things. The other keeps them going, or keeps them exactly where they were.

Both belong to Saturn in the old books, and that's about the only thing they share. Capricorn keeps the rules; Aquarius wants to rewrite them. Tradition sees a respectful sort of friction between the boss and the inventor, each convinced the other one is nearly right.

Where it comes from: comparing charts, from Babylon to your phone

Era by era, with sources. More in the Reading Room.

Ancientc. 450 BCEThe Babylonian zodiac settles into twelve equal zones, the frame later comparisons of signs are built on. ³
Ancient410 BCEThe earliest known horoscopes, from Babylon and Nippur, date to this year. ³
Classical2nd century CEPtolemy's Tetrabiblos names the aspects between signs and calls the trine and sextile harmonious, the square and opposition disharmonious. ^4,1
Classical2nd century CEPtolemy's chapter on the planets' houses gives both Capricorn and Aquarius to Saturn, whose two signs he places opposite the Sun’s and Moon’s signs. ¹
Classical2nd century CEPtolemy calls signs one apart disjunct, or alien: they share none of his aspects. Neighbours, he says, are turned away from one another. ¹
Classical2nd century CEIn his chapter on marriage, Ptolemy compares two charts: the Sun and Moon of one against the Sun and Moon of the other, reading trines and sextiles between them as concord and squares and oppositions as friction. ²
Classical2nd century CEHis chapter on friends and enemies does the same with the Sun, the Moon, the rising degree and the Lot of Fortune of both people. ²
Medieval12th centuryAbu Ma'shar's introduction to astrology circulates in Latin; the University of Edinburgh holds a 12th-century copy. ⁵
1800s1890Alan Leo's Astrologer's Magazine offers its annual subscribers a free horoscope by post. ⁶
1930s1937R. H. Naylor's newspaper horoscope, begun in 1930, is organised by the twelve sun signs. ⁷
1970s1978Linda Goodman's Love Signs is published by Harper & Row. ⁸
1980s–90s1980–1999Chart services run by computer arrive: Astrodienst in Zürich sells birth charts from 1980 and goes online in 1996. ⁹
Today202430% of US adults consult astrology, tarot or a fortune teller at least yearly, mostly for fun, according to Pew Research Center. ¹⁰

Worked out, not guessed

Capricorn is sign 10 of 12 and Aquarius is sign 11: one sign apart, 30°. Semi-sextiles always share nothing the old system counts: element, mode and polarity all differ. Of the 78 possible sun-sign pairings, 12 are semi-sextiles.
Venus never gets more than about 47° from the Sun, so a Capricorn's Venus is in one of five signs (Scorpio, Sagittarius, Capricorn, Aquarius or Pisces) and an Aquarius's in one of five (Sagittarius, Capricorn, Aquarius, Pisces or Aries). Which one is a matter of the year and the day.

Why do you respect them and still clash?

The Sun can’t answer that. These four can, and your card reads every one of them.

Venus · how you love

How do you love, and how do they want to be loved?

That's Venus. It never strays far from the Sun, so a Capricorn's Venus can only sit in Scorpio, Sagittarius, Capricorn, Aquarius or Pisces, and an Aquarius's Venus can only sit in Sagittarius, Capricorn, Aquarius, Pisces or Aries. Two people with the same sun sign can want completely different evenings.

Your card reads your Venus.
Mars · what you want

Why does every rule become a fight?

That's Mars: desire, temper, the way you chase what you're after. It can sit in any of the twelve signs, so two Aquarius born a season apart can want, and fight about, completely different things.

Your card reads your Mars.
The Moon · what you need

Why do they feel like home one day and a stranger the next?

That's the Moon: what you need when the door's shut and the day's gone wrong. It changes sign every two and a half days. If their Moon falls in your sign… well.

Your card reads your Moon.
The descendant · who you’re drawn to

Why do you keep falling for the same type?

That's your descendant, the edge of the seventh house: the sign setting in the west at your birth minute. Tradition reads it as the partner you keep noticing. It needs your birth time and place.

Your card reads your rising sign and your descendant.