The Big 3 — Sun, Moon, Rising
Sun sign
Also called: Star sign, zodiac sign
In one line — The zodiac sign the Sun was in when you were born. The default answer to 'what's your sign?' and the most widely known but least specific layer of your chart.
Your Sun sign represents your core identity, ego, and the energy you grow into as you mature. It's what newspaper horoscopes are written for — which is also why those horoscopes feel generic: 1/12 of the population shares your Sun sign.
In a full reading, the Sun is one voice among many. People with the same Sun can have wildly different charts because the Moon, Rising, and house placements vary.
Example
Born June 15? You're Gemini Sun — quick-minded, curious, comfortable juggling multiple identities. But your Moon might be Capricorn (private, ambitious) and your Rising might be Pisces (dreamy in first impressions) — three quite different selves in one person.
Moon sign
In one line — The zodiac sign the Moon was in when you were born. Represents your emotional weather, instincts, and how you process feelings privately.
The Moon is the inner life. Your Sun is who you are; your Moon is who you are when no one's watching. It governs your default mood, what makes you feel safe, your relationship to food, sleep, and home.
Moon sign is often a stronger predictor of compatibility than Sun sign — two people can share a Sun sign but have incompatible emotional needs if their Moons clash. The Moon changes signs every 2.5 days, so you need accurate birth date (and ideally time) to nail it.
Example
Moon in Cancer needs deep emotional safety to feel okay. Moon in Aquarius needs space and intellectual freedom to feel okay. Both can be loving partners, but they soothe themselves in opposite ways.
Rising sign
Also called: Ascendant, ASC
In one line — The zodiac sign that was rising on the eastern horizon at the exact minute of your birth. The mask you wear in first impressions — and the entry point to the 12 houses.
Rising sign changes every 2 hours, so you need your exact birth time to know it. Without time, your Rising is unknowable.
It shapes how strangers perceive you on first contact — your body language, your style, your physical vibe. Often quite different from how you feel inside (your Moon) or who you really are at core (your Sun). Many people read their Rising sign's horoscope and think 'this is more accurate than my Sun' — that's why.
Rising also determines which signs rule which houses in your chart, so it's the foundation of everything spatial in astrology.
Example
Rising in Leo walks into a room and is somehow noticed before they say anything. Rising in Scorpio walks into a room and people sense intensity before they understand why. Rising in Virgo walks into a room and is the most composed-seeming person there, even if internally a mess.
Big 3
Also called: Big Three, Sun-Moon-Rising
In one line — Your Sun, Moon, and Rising signs taken together. The minimum viable summary of who you are astrologically.
Sun = core identity. Moon = inner life. Rising = first impression. Together they answer 'who am I, how do I feel, and how do others see me?'
The Big 3 is what TikTok astrology runs on — it's enough nuance to feel personal without requiring a full chart reading. But it still misses Venus (love style), Mars (drive), Mercury (communication), and where each planet falls in the 12 houses.
If you're new to astrology, learn your Big 3 first. If you've already memorized those, the next step is your Venus and Mars signs.
Houses
Houses
Also called: 12 houses, astrological houses
In one line — The twelve 'rooms' of a birth chart, each governing a domain of life — self, money, communication, home, romance, work, relationships, etc.
While zodiac signs describe energy types, houses describe life areas where that energy plays out. Planets placed in a house bring their qualities into that domain.
The 12 houses are: 1st (self & body), 2nd (money & values), 3rd (communication & siblings), 4th (home & roots), 5th (creativity & romance), 6th (daily work & health), 7th (partnerships), 8th (intimacy & shared resources), 9th (philosophy & travel), 10th (career & public), 11th (community & friends), 12th (subconscious & hidden).
House placement often matters more than sign for predicting where in your life a planet's energy actually shows up.
Example
Venus in Pisces in the 10th house: love expressed through art and creativity, but the romance plays out publicly — co-workers, public partnerships, fame-adjacent contexts. The same Venus in Pisces in the 4th house: love expressed privately, at home, with family — different life entirely.
Placidus vs Whole Sign houses
In one line — Two different ways to divide the chart into 12 houses. Placidus uses time-based division (more common in modern Western astrology); Whole Sign assigns one full zodiac sign to each house.
Placidus calculates house cusps based on time of day, so houses end up unequal sizes (and the system distorts severely at high latitudes near the poles). It's the most common modern Western system because it gives interesting results in temperate latitudes.
Whole Sign is the older Hellenistic system: your Rising sign becomes the 1st house in full, the next sign becomes the 2nd house in full, and so on. Cleaner, simpler, and what most ancient astrologers actually used.
Many modern astrologers use both — Placidus for the angular houses (1, 4, 7, 10) and Whole Sign for everything else. Tarot by Hand birth chart readings use Placidus by default.
Technical & schools
Tropical vs Sidereal astrology
In one line — Two different ways of mapping zodiac signs to sky positions. Tropical uses Earth's seasons (Western default). Sidereal uses fixed star constellations (Vedic / Indian astrology default).
Earth's axis wobbles slowly (precession of the equinoxes), causing the actual constellations to drift by about 1° every 72 years relative to the seasons. This means tropical and sidereal zodiacs are now offset by ~24°.
If you're a Tropical Gemini, you're probably a Sidereal Taurus. Both are 'right' — they're measuring different things. Tropical Western astrology says 'the energy of Gemini begins when spring is fully established, regardless of which stars are behind the Sun.' Sidereal says 'the Sun is literally in front of Taurus stars right now.'
Tarot by Hand uses Tropical (Western) astrology — the standard for Co-Star, The Pattern, Sanctuary, and most English-language astrology.
Retrograde
In one line — A planet appearing to move backward in the sky from Earth's perspective. Doesn't literally reverse — it's an optical illusion caused by orbital speeds.
Mercury retrograde is the famous one — about 3-4 times a year for 3 weeks each. Popular astrology associates it with communication breakdowns, tech glitches, and old contacts resurfacing. The advice 'don't sign contracts during Mercury retrograde' has no empirical basis but does seem to give people a useful pause for review.
Other retrogrades:
• Venus retrograde (40 days, every 18 months) — relationships and self-worth themes resurface.
• Mars retrograde (10-11 weeks, every 2 years) — frustration and stalled drive.
• Outer planets retrograde for months at a time and matter mostly for slow personal-development arcs.
We read retrogrades as invitations to review, not as warnings to halt life.
Advanced
Synastry
Also called: Compatibility astrology
In one line — The astrological comparison of two birth charts to assess relationship compatibility — how each person's planets fall in the other person's houses and form aspects to the other's planets.
Synastry doesn't predict whether a relationship will work. It maps the dynamic — where attraction lives (Venus / Mars contacts), where the emotional weather syncs (Sun / Moon), where friction is honest (Saturn squares, oppositions across the 7th house axis).
Favorable synastry doesn't mean easy relationship; difficult synastry doesn't mean doomed. Two people can have textbook compatibility and not work, or have intense friction and stay together for life because the work is generative.
Our Compatibility Reading ($14.99) is a long-form synastry interpretation across both Big 3, Venus / Mars, and the friction houses.
Example
Your Venus in Pisces opposite their Mars in Virgo across the 2nd/8th house axis: the magnetic-but-can't-quite-meet dance of two people who want each other through mirror images. Often very passionate, often very repetitive in the same fight.
Transit
In one line — The current real-time position of a planet in the sky, compared to where the planets were at your birth. Transits are how astrology talks about 'what's happening to me now.'
Your birth chart is fixed — it's the sky at one moment. Transits are the sky right now, moving against that fixed backdrop. When a transiting planet hits a planet in your natal chart, that's the activation.
Key life transits to know about:
• Saturn return (around age 29 and 58) — the structural reset, where Saturn returns to where it was at birth.
• Jupiter return (every 12 years) — expansion and opportunity cycle.
• Pluto squares Pluto (around age 40) — the famous midlife crisis transit.
Transits are what apps like Co-Star push as daily horoscopes — but they only matter if they hit a sensitive point in your natal chart.
Apply it
Want your full chart read?
$9.99 one-time. Sun, Moon, Rising plus all 12 houses, interpreted as a single reading instead of three separate sign descriptions.
Get your birth chart reading →