Charts and placements
Birth chart. A map of the sky for the minute and town you were born in. Also called a natal chart. It doesn’t change.
Sign. One of twelve 30 degree slices of the zodiac. Signs describe the style in which a planet works.
Placement. Where a given planet sits in your chart, as in “my Venus is in Leo.”
Sun sign. The sign the Sun was in when you were born, and the one you probably know already.
Moon sign. The sign the Moon was in. Read as your emotional habits and needs. See Moon signs.
Rising sign, or Ascendant. The sign on the eastern horizon at your birth. It needs a known birth time. See Rising signs.
Big 3. Your Sun, Moon and Rising taken together. See Sun, Moon and Rising.
Descendant. The point directly opposite the Ascendant, where the 7th house begins. The app doesn’t compare it.
Midheaven, or MC. The highest point of the zodiac in the sky at your birth, linked with career and public life. It appears in your chart, but the app leaves it out when comparing two people.
House. One of twelve areas of life, worked out from your birth time and place. See the 12 houses.
House system. The method used to divide the chart into houses. There are several. The app uses Placidus, a common one.
Chart ruler. The planet that rules your Rising sign. Some astrologers give it extra weight.
Planets and points
Planet. In astrology, this includes the Sun and Moon, for short. See planets and points.
Personal planets. The Sun, Moon, Mercury, Venus and Mars. They move fast enough to describe you, not your age group.
Social planets. Jupiter and Saturn, which spend a year or more in a sign.
Outer or generational planets. Uranus, Neptune and Pluto. They move so slowly that people born within a few years share them, and the app doesn’t compare them with each other.
Retrograde. When a planet appears to move backward from Earth’s point of view. See retrogrades in a birth chart.
Dominant planet. The strongest planet in a chart. In the app, it’s called your strongest force. See your dominant planet.
Aspects and comparing
Aspect. An angle between two planets. Inside one chart it describes you, and across two charts it describes something between you.
Conjunction. About 0 degrees. Two planets act together. The app counts it as neither harmonious nor challenging.
Sextile. About 60 degrees. A light, friendly link that rewards some effort. Harmonious.
Square. About 90 degrees. Two planets want different things at once. Challenging.
Trine. About 120 degrees. An easy flow, usually between signs of one element. Harmonious.
Opposition. About 180 degrees. Two planets face off across the chart. Neither harmonious nor challenging on its own.
Minor aspects. Smaller angles such as 30, 45, 135 and 150 degrees. The app’s score notices them, and its written descriptions cover the five major ones.
Orb. The gap between an aspect and its exact angle. An angle of 93 degrees is a square with a 3 degree orb. Tighter usually means stronger.
Parallel. When two planets are at the same distance above or below the celestial equator. It’s read something like a conjunction, and the score takes it into account.
Synastry. Comparing two people’s birth charts. See what synastry is.
Composite chart. A single chart built from the midpoints between two people’s planets. The app doesn’t use one.
Mutual reception. Two planets each in the other’s home sign. The app adds this to harmony when comparing charts.
Harmonious, Challenging, Dynamic. The labels the app gives each area of a report. See what they mean.
Transit. A planet in today’s sky making an aspect to a point in your chart. See what a transit is.
Signs and strength
Element. Fire, earth, air or water. Each covers three signs.
Modality. Cardinal, fixed or mutable, describing how a sign deals with change. Each covers four signs. See elements and modalities.
Rulership. The link between a planet and the sign or signs it’s most at home in. Venus rules Taurus and Libra.
Essential dignity. How well a sign suits a planet. See essential dignity.
Exaltation, detriment, fall. A sign where a planet does especially well, the sign opposite its home, and the sign opposite its exaltation.
Sun sign astrology. The kind in magazine columns, based on your Sun alone. Fun, and a very small slice of a chart.
Terms the app doesn’t use
You’ll see these elsewhere, so it’s useful to know what they are. MatchMachine doesn’t calculate or score any of them.
North and South Node. Two points where the Moon’s path crosses the Sun’s apparent path, often read as a direction of growth and a set of old habits.
Lilith. Usually the Black Moon, a calculated point on the Moon’s orbit rather than an object. It’s often linked with what a person refuses to tame or hide.
Part of Fortune. A point calculated from the Sun, Moon and Ascendant, traditionally linked with ease and wellbeing.
Chiron. A small body between Saturn and Uranus, often read as a tender spot that can teach you something.
Vertex. A calculated point, needing a birth time, that some astrologers link with significant meetings.
Sabian symbols. A set of images assigned to each degree of the zodiac.
Sidereal zodiac. A zodiac measured from the fixed stars, about 24 degrees off from the tropical zodiac used by the app and by most Western astrology. If a site gives you a different Sun sign, this may be why.