Aries Moon and Pisces Moon compatibility is a meeting of next-door signs. Pisces is the last sign of the zodiac. Aries is the first. The Moon walks out of one and into the other about once a month. Yet the oldest rule book on the signs says these neighbors cannot see each other.
That rule comes from Ptolemy. In his reading by whole signs, signs that sit side by side are turned away. The later word is aversion. Read by degrees, though, the same two signs mirror each other across the first day of spring. So this pair has two answers in the old books, and both are worth knowing.
Below, we set out both readings, the rank each Moon holds, and the numbers we measured over eight centuries of real Moon positions. Astrology is not a science. Treat this page as a way to talk about two styles of feeling, not as a forecast.
Six facts about this pair
| Question | Answer. |
|---|---|
| How far apart are the signs? | One sign, or 30 degrees, with no classic aspect. |
| What did Ptolemy say, by whole signs? | Signs one apart are turned away from each other. |
| What changes when you read by degrees? | Aries and Pisces become mirror signs. |
| How many couples sit on mirror degrees? | About 1 in 15 within 1 degree, and 19 percent within 3 degrees. |
| How strong is the Moon in each sign? | It holds no main rank in either one. |
| How common is the pair? | About 1 couple in 72, like every mixed Moon pair. |
The Moon sign, briefly
Your Moon sign is the slice of sky the Moon was in when you were born. There are twelve slices of 30 degrees. The Moon goes round all twelve in about 27.3 days. So it stays about two and a quarter days in each sign.
Astrologers read the Moon as your private self. It is the mood under the words: how you calm down, what you need when you are low, how you look after the people you love. Moon sign compatibility compares two of those private selves. The full method for all 78 pairs is in our guide to moon sign compatibility.
A word of caution
No study has shown that Moon signs predict how a couple will fare. The largest test on record looked at Sun signs. David Voas studied 10.3 million married couples in the 2001 census of England and Wales. He found no effect of the signs on who married whom. A slight excess of same-sign couples came from mistakes in typing the forms.
Moon signs have never been tested on that scale. So we give no score and no verdict. We use the old rules as a shared language, and we say where each rule comes from.
Neighbors with no classic aspect
An aspect is a set angle between two points in the sky. Claudius Ptolemy, writing in Alexandria around 150 AD, counts four of them in the Tetrabiblos. They are the opposition, the trine, the square and the sextile. Signs one apart, at 30 degrees, are not on his list.
Modern astrologers gave that 30 degree angle a name: the semi-sextile, or half a sextile. Most treat it as a mild link. It is a later idea, not an old one.
The two signs share no type in the old scheme either. Aries is fire and Pisces is water. Aries is cardinal, meaning it opens a season. Pisces is mutable, meaning it closes one. Aries is a masculine sign and Pisces a feminine one, old labels for signs that take turns around the wheel. We sorted all 78 Moon pairs by angle, element and mode. Aries and Pisces is the only pair that joins fire and water across one sign, from cardinal to mutable.
Reading one: turned away
In book one, chapter 16, Ptolemy names the signs that have no tie at all. He calls them disjunct, or alien. They have no aspect. They are not linked by the length of the day, nor by the time they take to rise. He says they are one or five signs apart. Signs one apart, he writes, are turned away from each other.
By whole signs, Aries and Pisces fit that rule. Ptolemy’s list of linked pairs in chapter 14 runs Taurus with Pisces, Gemini with Aquarius, and so on. Aries is left out. His translator, Frank Robbins, points this out in a note. So in the whole-sign reading, an Aries Moon and a Pisces Moon are averted. They share a border but face in different ways.
As a symbol, aversion is not hostility. It is a blind spot. Each Moon works in a way the other does not see at first. The Aries Moon acts on a feeling. The Pisces Moon soaks it up. Aries can miss how much Pisces has taken in. Pisces can miss that Aries has already moved on and means no harm.
Reading two: mirror signs
Ptolemy’s rule in chapter 14 speaks of parts of the zodiac the same distance from the first day of spring. Read by degrees, that rule does join Aries and Pisces. Take 10 degrees of Aries. It sits 10 degrees after the spring point. Take 20 degrees of Pisces. It sits 10 degrees before. Those two points rise in the same time and sit the same distance from the sky’s equator.
William Lilly, in Christian Astrology of 1647, calls such a mirror point a contra-antiscion. Our page on Pisces and Aries compatibility for Sun signs covers this reading in depth. It also timed how fast the two signs rise over four US cities. We do not repeat that work here. We add the Moon version of the count.
How many Moon couples sit on mirror degrees?
Two Moons form a mirror pair when their degrees add up to 30. For example, 12 degrees of Aries mirrors 18 degrees of Pisces. We asked what share of Aries and Pisces Moon couples come close to that.
The Moon’s place within a sign is spread almost evenly over time, and the two partners are independent. So the share has a plain form. We checked it against the true spread of Moon degrees from 1600 to 2400, and the two agree.
| How close to a mirror | Share of Aries and Pisces Moon couples | Put simply. |
|---|---|---|
| Within 1 degree | 6.56 percent | About 1 couple in 15. |
| Within 3 degrees | 19 percent | About 1 couple in 5. |
So most couples in this pair do not sit on mirror degrees. For the one in fifteen who do, the degree reading has something real to point at. The whole-sign reading, by contrast, applies to every couple.
Which reading should you use?
Both are in the old books, and we do not pick one. The whole-sign reading is simple and applies to all. It says: neighbors, turned away. The degree reading is more precise but needs birth times, since the Moon moves about 13 degrees a day. It says: mirror points, for the few who have them.
Lilly adds a twist. He says a contra-antiscion has the nature of a square or an opposition. So even the tie that joins these signs carries some tension in his reading. Both readings agree on one thing. This is not an easy, open link like a trine.
Where each Moon stands
The old books rank each planet in each sign. The four main ranks are home, exaltation, exile and fall. For the Moon, Lilly gives home in Cancer, exaltation in Taurus, exile in Capricorn and fall in Scorpio.
Neither Aries nor Pisces is on that list. So both Moons are peregrine, an old word for a wanderer. A wanderer is not helped or held back by its sign. It acts on its own terms.
The two Moons still differ in mood. The Aries Moon is quick, frank and short-lived in its anger. You can read more on our Moon in Aries page. The Pisces Moon is open, absorbent and slow to draw lines. Our Moon in Pisces page timed each of its passages.
What the old symbols suggest
- Aries leads with action. Pisces leads with feeling.
- Aries forgets a fight fast. Pisces keeps the mood of it for longer.
- Pisces can show Aries what lies under the anger.
- Aries can show Pisces that a need can be said out loud.
- The blind spot runs both ways. Each one has to ask, not guess.
The seam of the zodiac
This pair has one practical quirk. The Moon moves from Pisces into Aries once every 27.3 days or so. On that day, a person born in the morning and one born at night can land on either side of the seam.
A free tool with no birth time uses noon. On a day when the Moon changes sign, the noon guess can put the wrong sign on the chart. We counted every sign change of the Moon from 1600 to 2400. On 43.92 percent of days, the Moon starts in one sign and ends in the next. The noon guess gives the wrong Moon sign for about 11 percent of births, or 1 in 9.
For a couple, the Moon pair is wrong in about 21 percent of cases, or 1 in 5. Here that has a twist. A wrong Pisces Moon is always really an Aries or an Aquarius Moon, one of its two neighbors. So a couple read as Aries and Pisces could in truth be two Aries Moons or two Pisces Moons, among other pairs. Only about 31 percent of couples have both Moon signs fixed by the date alone. Check both birth times first.
New Moon and Full Moon births
Some people are born with the Moon in the Sun’s own sign, close to a New Moon. Others are born with the Moon across from the Sun, close to a Full Moon. The shares shift a little by Moon sign. The cause is the Sun’s pace, which is slowest in early July.
| Moon sign | Near a New Moon | Near a Full Moon. |
|---|---|---|
| Aries Moon | 8.21 percent | 8.18 percent. |
| Pisces Moon | 8.07 percent | 8.32 percent. |
For the couple, about 15.6 percent include at least one partner born near a New Moon. About 15.8 percent include one born near a Full Moon. Our page on moon phase compatibility covers what astrologers make of this.
How common is the pair?
Over the years 1600 to 2400, each Moon sign holds between 8.33 and 8.34 percent of the time. The gaps between signs are smaller than the gap between our two methods. They mean nothing.
So any mixed Moon pair, such as Aries and Pisces, comes up for about 1 couple in 72. A same-sign pair comes up for about 1 couple in 144. You can compare with our pages on two Pisces Moons and on Aquarius and Pisces Moons, the other neighbor of Pisces.
How we measured it
We used two separate methods. The first used the Astronomy Engine library. It found every sign change of the Moon, Sun and Venus from 1600 to 2400, to a tenth of a second, then added up the exact time in each sign. The second used the Swiss Ephemeris. It stepped through the same years once an hour, on a grid set half an hour apart from the first.
The two agree within 0.04 points on every Moon share. Days and noon charts use Greenwich time. The rules on signs come from Ptolemy’s Tetrabiblos, book one, in the Robbins translation, and from Lilly’s Christian Astrology.
Frequently asked questions
Are Aries Moon and Pisces Moon compatible?
The old books give two answers. By whole signs, Ptolemy calls neighbors turned away, with no tie. By degrees, the signs mirror each other. No study shows that Moon signs decide how a couple does.
What does aversion mean in astrology?
It is the state of two signs with no link at all in Ptolemy’s scheme. They are one or five signs apart. As a symbol, it is a blind spot, not a clash.
What are mirror degrees?
They are two points the same distance from the first day of spring, one on each side. Lilly calls them contra-antiscia. About 1 Aries and Pisces Moon couple in 15 sits within 1 degree of a mirror.
Is the Moon strong in Aries or Pisces?
Neither. The Moon holds no main rank in either sign. The old word is peregrine, meaning a wanderer.
Why should I check the birth time for this pair?
The Moon crosses from Pisces into Aries about once a month. On that day, the hour decides the sign. A noon guess gets about 1 chart in 9 wrong.