Natal charts
Venus and Mars in the 8th house: what they mean in a birth chart and in synastry
In Western astrology, Venus or Mars in the 8th house carries that planet's themes into intimacy, trust and everything two people come to share. Venus in the 8th is read as a longing to merge with a partner, down to joint money, while Mars in the 8th brings intensity and drive to closeness, along with quarrels that flare up and settle just as fast. Neither placement is rare: across 100,000 random birth times in London, Venus sits in the 8th house for 8.2% of people and Mars for 8.3%. Venus in the 8th also says something about the birth itself: it only happens to people born between late morning and shortly after sunset, and like any house placement it can only be found with an exact birth time. In synastry, the comparison of two charts, a partner's Venus falls in your 8th house in about one random couple in twelve. You can see your own Venus, Mars and 8th house in the sexual astrology chart calculator. You can also check your sexual compatibility by date of birth with a partner: the comparison sets each person's Venus against the other's Mars, element by element.
Venus in the 8th means a daytime birth
Houses are counted from the horizon of the birthplace, and the Sun passes through all twelve of them every day. Shortly after sunrise it stands in the 12th house, around noon it reaches the 10th, and through the afternoon it sinks through the 9th and 8th towards the western horizon, where the 7th house begins. Seen from Earth, Venus never strays more than 47 degrees from the Sun, so when Venus is in the 8th, the Sun has to be close by.
That is exactly what our London sample shows. For people with Venus in the 8th house, the Sun was above the horizon in 89.4% of cases and in the 7th, 8th or 9th house in 80.1%. The rest were split roughly equally between late morning and midday, with the Sun in the 11th or 10th house, and the time just after sunset, when it had sunk into the 6th. In the 12th house and in houses 1 to 5, which cover the evening, the night and the early morning, the Sun never appeared at all. So if you were born in the middle of the night and a chart program puts your Venus in the 8th house, check the data first: a.m. and p.m. or the time zone may have been mixed up.
Mars follows no such rule, since it can stand at any distance from the Sun. For people with Mars in the 8th, the Sun was above the horizon in about two cases out of three (64.9%), so night-born people can have Mars there too.
How often each placement occurs
We calculated houses in the Placidus system, the one most chart software uses, for 100,000 random birth times between 1950 and 2008 in three cities and counted where Venus and Mars fell.
| City | Venus in the 8th | Mars in the 8th | Both | At least one |
|---|---|---|---|---|
| London | 8.2% | 8.3% | 1.2% | 15.3% |
| New York | 8.2% | 8.4% | 1.2% | 15.4% |
| Sydney | 8.2% | 8.4% | 1.4% | 15.3% |
The city barely matters. About one person in six or seven has Venus or Mars in the 8th house, and one or two in a hundred have both. Every personal planet (the Sun, Moon, Mercury, Venus and Mars) lands in the 8th about as often, as we showed in what the 8th house means in astrology.
What the old texts said
The oldest descriptions have nothing to do with intimacy. Firmicus Maternus, who wrote his Mathesis in the fourth century, says that Venus in the eighth place, as houses were then called, "will give a wife late" in a daytime birth, and an unsuitable one at that, while in a night birth she brings wealth through the death of prominent women. Mars in the same place denies an inheritance or strips the person of property when the birth is by day, and by night makes people hot-headed, shrewd and drawn to danger; in Firmicus only a favourable angle (an aspect) from Jupiter or Venus softens it. Two centuries earlier Vettius Valens had written that benefic planets, Venus among them, are "ineffectual and weak" in this place, though he also noted that, counted from the 7th place of women, the 8th concerns livelihood, which is where today's idea of joint resources comes from.
Alan Leo, early in the twentieth century, still read both planets through money and death. In How to Judge a Nativity, Venus in the eighth "denotes a peaceful and easy death" and "promises financial gain by marriage or partnerships", while Mars there "causes much trouble in connection with finance after marriage, either the partner is extravagant or wastes money foolishly." Leo was also among the first to say the eighth house "indicates the sex tendencies", yet intimacy appeared in readings of Venus and Mars in the 8th only later, after the house had come to be associated with sex.
The connection between the eighth house and physical intimacy grew gradually from its traditional association with the sign of Scorpio. In his 1647 book Christian Astrology, the English astrologer William Lilly noted that the eighth house shared its meaning with Scorpio and governed the "privy-parts" of the body, although he still looked to the seventh house to judge matters of love. In the 1970s, the astrologer Zipporah Dobbyns articulated the Twelve-Letter Alphabet, a framework that completely equated the signs of the zodiac with the astrological houses. This modern doctrine took the anatomical connection recorded by older writers and expanded it into the psychological themes of deep trust, boundaries and vulnerability that are now read into Venus and Mars.
Your birth time and your house system
Houses move with the Ascendant, the sign rising in the east at the moment of birth, which turns through the whole zodiac in a day. We checked what happens when a birth time is only known within a margin. With a margin of 15 minutes either way, Venus leaves the 8th house at one edge of that window or the other for 26.6% of the people who have it there, and Mars for 24.9%. With a margin of an hour, the figures rise to 88.7% and 86.8%, which is nearly everyone.
The house system changes the answer as well. Under whole-sign houses, where the 8th house is simply the eighth sign counted from the rising sign, only 44.9% of Placidus "Venus in the 8th" charts keep Venus in the 8th, and only 40.6% keep Mars there; the rest move into a neighbouring house. It is worth knowing which system your software uses. Our calculator uses Placidus.
Your partner's Venus or Mars in your 8th house
In synastry, astrologers place one person's planets in the other person's houses. When a partner's Venus or Mars falls in your 8th house, modern synastry readings take it as a pull towards intimacy specifically: with this person you want to open up and trust, and sometimes to argue about control and boundaries.
To see how common that is, we paired 50,000 random charts from the same London sample. A partner's Venus landed in the other person's 8th house in 8.5% of couples, Mars in 8.6%, and one or the other in 15.7%. Counting both directions, 28.9% of couples had someone's Venus or Mars in the other's 8th house, more than one couple in four. Mutual Venus, with each partner's Venus in the other's 8th, turned up in 0.7% of couples. How the Venus of one person and the Mars of another meet in a chart comparison is covered in Venus–Mars synastry.
What the calculation cannot tell you
Given the date, time and place, house positions are exact to a fraction of a degree, and the calculator shows which house each planet occupies. What the tradition reads into Venus and Mars in the 8th house is beyond anything a calculation can test. In a double-blind test published in Nature in 1985, Shawn Carlson asked astrologers to match charts with personality profiles, and they did no better than chance. Geoffrey Dean and Ivan Kelly reviewed dozens of similar tests in 2003 and reached the same conclusion.