The Astrometric Lexicon

The fraction of light reflected by a surface. The Moon's average albedo is only 0.12, meaning it reflects just 12% of sunlight. Despite this, it is the brightest object in the night sky due to its proximity.

The time it takes for the Moon to travel from perigee to perigee, approximately 27.55 days. This cycle influences tidal forces and is distinct from the synodic month.

The point in the Moon's orbit when it is farthest from Earth, approximately 405,500 km. A Full Moon at apogee is sometimes called a Micromoon.

The zodiac sign rising on the eastern horizon at the moment of birth, also called the Rising Sign. It shapes first impressions, outward appearance, and how others perceive you. The Ascendant changes approximately every 2 hours, making birth time essential for accurate calculation.

The angular relationship between two celestial bodies as viewed from Earth. Major aspects include conjunction (0°), sextile (60°), square (90°), trine (120°), and opposition (180°). Each aspect has distinct astrological qualities.

The angular difference between the Tropical and Sidereal zodiacs, caused by the precession of Earth's axis. Currently approximately 24°, it increases by about 1° every 72 years. The Lahiri ayanamsa is the most commonly used value.

A field that combines psychological theory with conventional economics to explain why investors make irrational financial decisions. The lunar effect in finance is often studied within this context.

Two or more runes combined into a single symbol, merging their individual meanings into a unified intention. Bindrunes are used as talismans, meditation focuses, or personal sigils. For example, combining Fehu (wealth) and Wunjo (joy) creates a bindrune for 'joyful abundance.' Creating bindrunes is a personal, creative practice.

An agricultural approach developed by Rudolf Steiner that aligns planting, cultivating, and harvesting with lunar phases and zodiac signs. Water signs favor leaf crops, Earth signs favor root crops, Air signs favor flowers, and Fire signs favor fruit and seed.

The second Full Moon in a single calendar month. This occurs roughly every 2.7 years. The original meaning (from the Maine Farmer's Almanac) referred to the third Full Moon in a season with four.

A predictable pattern in financial markets related to the calendar, such as the Turn-of-Month effect or the January effect. These must be controlled for when analyzing lunar effects.

A ten-card tarot spread and one of the oldest and most comprehensive layouts. Positions cover the central issue, crossing influences, subconscious foundations, recent past, best outcome, near future, the querent's attitude, external influences, hopes and fears, and final outcome.

The ancient arrangement of the seven classical visible planets by their apparent orbital speeds from slowest to fastest: Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon. Forms the astronomical basis for the planetary rulers of the days of the week.

A biological rhythm with a period of approximately 29.5 days, matching the lunar synodic cycle. Research published in Science Advances has demonstrated circalunar rhythms in human menstrual cycles, sleep patterns, and mood fluctuations. These rhythms may be entrained by moonlight intensity and/or gravitational cycles, though the exact mechanisms remain under investigation.

The hypothesis that human biological circalunar rhythms may subtly influence aggregate investor mood or risk aversion on a 29.5-day cycle.

The practice of growing specific plants together for mutual benefit — pest deterrence, pollination support, nutrient sharing, or shade provision. In lunar gardening, companion planting is combined with phase timing: sow companion pairs together during favorable moon phases to maximize both the lunar and symbiotic benefits.

An aspect formed when two celestial bodies occupy the same degree of the zodiac (0° apart). Conjunctions represent fusion, intensification, and new beginnings. The energy of the two planets blends — sometimes harmoniously, sometimes with tension, depending on the planets involved. A Sun-Moon conjunction is a New Moon.

The harmonic aspect comparison between active real-time planetary transits and a company's legal incorporation natal birth chart.

The 16 personality cards of the Minor Arcana — four in each suit: Page (student/messenger), Knight (action/quest), Queen (nurturing mastery), and King (authority/leadership). Court cards often represent people in the querent's life or aspects of the querent's own personality.

A lunar phase where less than half of the Moon's visible surface is illuminated, appearing as a thin curved sliver. The Waxing Crescent follows the New Moon; the Waning Crescent precedes the next New Moon.

A subdivision of each zodiac sign into three 10° segments. Each decan is ruled by a different planet, adding nuance to the sign's interpretation. The first decan of a sign is considered the purest expression of its energy.

The celestial equivalent of terrestrial latitude. Measures the angular distance of a celestial body north (+) or south (-) of the celestial equator, spanning from +90° at the North Celestial Pole to -90° at the South Celestial Pole.

The normal forward motion of a planet through the zodiac, as opposed to retrograde. When a planet 'stations direct,' it resumes forward motion after a retrograde period. Often considered a time of clarity and forward progress.

The practice of seeking knowledge of the future or the unknown through ritual, symbolic, or intuitive methods. Tarot is one form; others include astrology, runes, scrying, and the I Ching. In a modern context, divination is often understood as a tool for self-reflection and pattern recognition rather than literal prophecy.

The faint illumination of the Moon's dark side caused by sunlight reflecting off Earth's surface and oceans. Most visible during the Crescent phases as a ghostly glow on the unlit portion of the Moon.

An astronomical event where one celestial body moves into the shadow of another. Lunar eclipses occur when Earth's shadow falls on the Moon; solar eclipses when the Moon blocks the Sun.

The apparent path of the Sun across the sky over the course of a year, defined by Earth's orbital plane. The Moon and planets stay close to this line, which is why the zodiac belt follows it.

The oldest and most widely used runic alphabet, consisting of 24 runes divided into three groups of eight called 'aetts.' Named after its first six letters (F-U-Th-A-R-K), it dates to roughly 150–800 CE. Each rune represents both a sound and a concept: Fehu (ᚠ) means 'cattle/wealth,' Uruz (ᚢ) means 'aurochs/strength,' and so on through Othala (ᛟ), meaning 'heritage.'

One of four classical elements (Fire, Earth, Air, Water) associated with groups of three zodiac signs. Fire signs (Aries, Leo, Sagittarius) are active and creative. Earth signs are practical. Air signs are intellectual. Water signs are emotional and intuitive.

One of two dates per year (around March 20 and September 22) when day and night are approximately equal in length. The vernal equinox marks the start of Aries in the Tropical zodiac.

A specific timeframe surrounding an event used to analyze its impact on an asset. In Market Tides, this typically spans a few days before and after a New or Full Moon.

A widely used asset pricing model and data library in empirical finance. It provides foundational market data for testing anomalies and is a key data source for Market Tides.

The lunar phase when exactly half of the Moon's visible surface is illuminated, occurring about a week after the New Moon. Called 'First Quarter' because the Moon has completed one-quarter of its orbit around Earth.

A biodynamic gardening day when the Moon is in an Air sign (Gemini, Libra, Aquarius). Ideal for planting flowers and flowering vegetables like broccoli and cauliflower.

A biodynamic gardening day when the Moon is in a Fire sign (Aries, Leo, Sagittarius). Ideal for planting fruit trees, tomatoes, peppers, and harvesting seeds.

The lunar phase when the Moon is on the opposite side of Earth from the Sun, fully illuminating its visible surface. Each month's Full Moon has traditional names from various cultures (e.g., Wolf Moon, Harvest Moon).

A lunar phase where more than half but less than all of the Moon's visible surface is illuminated. The Waxing Gibbous phase leads to the Full Moon; the Waning Gibbous follows it.

The percentage of the Moon's visible surface lit by the Sun, ranging from 0% (New Moon) to 100% (Full Moon). Illumination determines the visual phase of the Moon.

A style of tarot reading that prioritizes the reader's felt response to the imagery, colors, and symbols on the cards over memorized textbook meanings. Intuitive readers treat the cards as mirrors for the subconscious, allowing personal associations and narrative instinct to guide interpretation.

A continuous count of days elapsed since the beginning of the Julian Period on January 1, 4713 BC (proleptic Julian calendar). Conceived by French scholar Joseph Justus Scaliger in 1583, the Julian Day system is the universal standard in astrophysics and celestial mechanics, eliminating complications from leap years, calendar changes, and timezones.

A biodynamic gardening day when the Moon is in a Water sign (Cancer, Scorpio, Pisces). Ideal for planting and tending leafy vegetables like lettuce, spinach, and herbs.

A slight wobble of the Moon that allows us to see approximately 59% of its surface over time, rather than just 50%. Caused by the Moon's elliptical orbit and the tilt of its axis relative to its orbital plane.

A timekeeping system measured relative to the distant fixed stars rather than the Sun. LST indicates the hour angle of the vernal equinox relative to the observer's local meridian. When an astronomical body culminates overhead, its Right Ascension exactly equals the observer's LST.

An observational anomaly in financial markets where asset returns or volatility appear to correlate with the lunar cycle. Research generally investigates whether returns are significantly different during the New Moon versus the Full Moon.

The practice of timing gardening activities to the Moon's phase and zodiac sign. Waxing phases favor above-ground crops and planting; waning phases favor root crops, pruning, and composting. Used worldwide for centuries.

The quantitative and statistical study of financial market behavior across synodic and anomalistic lunar phases, backtested over 100 years of trading data.

The two points where the Moon's orbit crosses the ecliptic plane. The North Node (Rahu) represents destiny and growth; the South Node (Ketu) represents past patterns and release. The nodes complete a cycle every 18.6 years.

The practice of aligning tarot readings with the lunar cycle. New Moon readings focus on intentions and beginnings, Full Moon readings on culmination and release, and specific phases correspond to different suits and arcana. This practice bridges the moon's rhythmic energy with the reflective nature of tarot.

A complete lunar cycle from one New Moon to the next, averaging 29.53 days. Also called a synodic month. Each lunation is numbered sequentially — the count began in 1923 with lunation 1 (January 17, 1923).

The 22 trump cards of a tarot deck, numbered 0 (The Fool) through 21 (The World). These cards represent significant life events, spiritual lessons, and archetypal energies. A reading heavy in Major Arcana suggests forces beyond day-to-day control are at play.

The large, dark basaltic plains on the Moon's surface, formed by ancient volcanic eruptions. The name means 'seas' in Latin — early astronomers mistook them for actual bodies of water. Maria cover about 16% of the Moon's surface, mostly on the near side, and have lower albedo (reflectivity) than the surrounding highlands.

The study of lunar cycles and historical financial market behavior. It examines empirical asset data across decades to observe statistical relationships between Moon phases and market performance.

A hormone produced by the pineal gland in response to darkness, regulating sleep-wake cycles. Research has shown that melatonin levels fluctuate with the lunar cycle — decreasing around the Full Moon — even in controlled laboratory conditions without moonlight exposure. This suggests a possible internal circalunar clock influencing human sleep architecture.

A period when Mercury appears to move backward through the zodiac from Earth's perspective, occurring roughly three times per year for about three weeks each. Astrologically associated with communication breakdowns, travel delays, technology glitches, and misunderstandings. Often considered a time to review, revise, and reflect rather than initiate new ventures.

The instant a celestial object crosses the observer's local meridian, reaching its highest angular altitude above the horizon for that diurnal cycle.

The 56 cards of a tarot deck divided into four suits: Cups (Water/emotions), Wands (Fire/creativity), Swords (Air/intellect), and Pentacles (Earth/material). Each suit runs from Ace through 10, plus four court cards. These cards address everyday situations and choices.

One of three qualities (Cardinal, Fixed, Mutable) that describe how a zodiac sign expresses its energy. Cardinal signs initiate, Fixed signs sustain, and Mutable signs adapt. Each element has one sign of each modality.

The zodiac sign the Moon occupied at the exact time of your birth. While your Sun sign reflects your core identity, your Moon sign governs your emotional inner world — how you process feelings, seek comfort, and instinctively respond to stress. It's often considered the most important placement for understanding emotional compatibility.

The time when the Moon appears above the eastern horizon. Unlike sunrise, moonrise time shifts roughly 50 minutes later each day because the Moon orbits Earth. Varies significantly by latitude and season.

The time when the Moon disappears below the western horizon. On some days, the Moon may not set at all (circumpolar Moon) or may not rise, depending on the observer's latitude and the Moon's declination.

A map of the sky at the exact moment and location of your birth, showing the positions of the Sun, Moon, planets, and zodiac signs. Also called a birth chart. It forms the foundation of personal astrology, with each planetary placement influencing different aspects of personality, relationships, and life path.

The lunar phase when the Moon is positioned between Earth and the Sun, making its illuminated side face away from Earth. The Moon is invisible or nearly invisible. In many traditions, the New Moon represents new beginnings and intention-setting.

The fraction of the Sun's disc covered by the Moon during a solar eclipse, expressed as a percentage. A total eclipse has 100% obscuration along the path of totality. Varies by observer location.

An aspect formed when two celestial bodies are 180° apart — directly across the zodiac from each other. Oppositions create tension, awareness, and the need for balance between two competing energies. A Sun-Moon opposition is a Full Moon. Challenging but deeply illuminating.

The lighter, outer part of a shadow where only a portion of the light source is blocked. A penumbral lunar eclipse is subtle — the Moon dims slightly but doesn't turn red.

The point in the Moon's orbit when it is closest to Earth, approximately 363,300 km away. A Full Moon at perigee is popularly called a Supermoon.

A non-parametric statistical method that shuffles data points over many iterations to determine the probability that an observed effect (like a lunar spread) occurred by chance.

The shape of the illuminated portion of the Moon as seen from Earth. There are eight named phases in a complete cycle: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Third Quarter, and Waning Crescent.

In the Chaldean system, each day of the week is governed by a planet: Sunday (Sun), Monday (Moon), Tuesday (Mars), Wednesday (Mercury), Thursday (Jupiter), Friday (Venus), Saturday (Saturn). The planetary hour system extends this to hours within each day.

The slow, 25,772-year wobble of Earth's rotational axis, causing the equinoxes to shift westward against the backdrop of stars. This is why the Tropical and Sidereal zodiacs diverge over time.

The person seeking answers through a tarot reading. The querent may ask a specific question or request a general reading about their life's current trajectory. In self-readings, the querent and the reader are the same person.

The apparent backward motion of a planet as seen from Earth, caused by differences in orbital speed. Mercury retrogrades 3-4 times per year for about 3 weeks each time. Astrologically associated with disruptions in communication, travel, and technology.

A card drawn upside-down during a reading. Reversed cards are interpreted differently from upright ones — often indicating blocked energy, internalized qualities, delays, or the shadow side of the card's meaning. Not all readers use reversals; it's a matter of personal practice.

The celestial equivalent of terrestrial longitude. Measured eastward along the celestial equator from the First Point of Aries (Vernal Equinox) to the body's hour circle in hours (0h–24h), minutes, and seconds.

A biodynamic gardening day when the Moon is in an Earth sign (Taurus, Virgo, Capricorn). Ideal for planting and tending root vegetables like carrots, potatoes, and onions.

A method of rune divination where runes are drawn from a bag or cast onto a cloth, and their positions and relationships are interpreted. Methods range from drawing a single rune for daily guidance to casting all 24 onto a cloth and reading only those that land face-up. Like tarot, rune casting is used as a reflective tool rather than literal prophecy.

A structured layout for drawn runes, similar to tarot spreads. Common rune spreads include the single rune draw (daily guidance), three-rune spread (situation-challenge-outcome), and the nine-rune cast (a comprehensive reading). Each position in the spread carries a specific meaning that shapes interpretation.

An ancient alphabetic system originating in Germanic and Norse cultures, used both for writing and divination. Each rune carries a symbolic meaning beyond its phonetic value. In divinatory practice, runes are carved or painted on stones, wood, or bone and drawn or cast to gain insight into questions. The most common system is the Elder Futhark (24 runes).

A period of approximately 18 years, 11 days, and 8 hours after which a nearly identical eclipse will occur. Eclipses in the same Saros series share similar characteristics. There are currently about 40 active Saros series.

The study and mapping of the Moon's surface features — its maria (dark plains), craters, mountains, and rilles. The term comes from Selene, the Greek goddess of the Moon. Selenography has been practiced since Galileo first turned a telescope toward the Moon in 1609.

An aspect formed when two celestial bodies are 60° apart, typically in compatible elements. Sextiles represent opportunity, cooperation, and creative potential — but unlike trines, they require conscious effort to activate. Think of them as open doors that you still need to walk through.

The time it takes the Moon to return to the same position relative to the stars, approximately 27.32 days. Shorter than a synodic month because it doesn't account for the Earth's orbital motion.

The zodiac system used in Vedic (Jyotish) astrology, aligned with the actual positions of the constellations. Due to precession, it currently differs from the Tropical zodiac by about 24°.

A card chosen to represent the querent or the central theme of a reading. It may be selected deliberately (often a court card matching the querent's personality or zodiac sign) or drawn randomly. Some spreads use a significator; others do not.

One of two dates per year (around June 21 and December 21) when the Sun reaches its maximum or minimum declination. The summer solstice is the longest day; the winter solstice is the longest night.

A specific layout pattern for tarot cards, where each position holds a designated meaning (e.g., past, present, future; challenge, advice, outcome). Common spreads include the three-card spread for quick readings and the Celtic Cross for comprehensive analysis.

An aspect formed when two celestial bodies are 90° apart. Squares create friction, challenge, and the motivation to act. They represent internal or external conflict that demands resolution. Though uncomfortable, squares are considered the engine of growth — they force change where trines allow stagnation.

The moment when a planet appears to stop moving before changing direction — either from direct to retrograde (station retrograde) or from retrograde to direct (station direct). Astrologically, stations are considered potent moments of concentrated planetary energy.

The exact geographical coordinate on Earth where the Moon is positioned directly at the 90° zenith overhead at any given instant. Its latitude equals the Moon's declination, and its longitude corresponds to the Moon's Greenwich Hour Angle.

The four divisions of the Minor Arcana, each associated with an element and domain of life: Cups (Water — emotions, relationships, intuition), Wands (Fire — creativity, ambition, will), Swords (Air — thought, conflict, truth), and Pentacles (Earth — health, money, nature). These elemental associations directly parallel the zodiac element system.

A Full Moon occurring near perigee, appearing up to 14% larger and 30% brighter than a Full Moon at apogee. The term was coined by astrologer Richard Nolle in 1979.

The time between two successive New Moons, approximately 29.53 days. This differs from a sidereal month (27.32 days) because the Earth is also orbiting the Sun.

The cumulative return trajectory of an asset across the 29.5-day synodic lunar cycle. It visualizes how market performance varies continuously from New Moon to Full Moon and back.

The alignment of three or more celestial bodies. New Moons and Full Moons are both syzygies — the Sun, Earth, and Moon are approximately aligned. The word comes from the Greek for 'yoked together.'

A system of divination using a deck of 78 illustrated cards, divided into the Major Arcana (22 cards representing life's spiritual lessons) and the Minor Arcana (56 cards reflecting daily trials and tribulations). Tarot is used as a tool for introspection, meditation, and symbolic storytelling rather than fortune-telling in a literal sense.

The boundary line between the illuminated and dark portions of the Moon. The terminator is where the Sun is rising or setting on the lunar surface — shadows are longest here, making craters and mountains most visible through a telescope.

Card 0 of the Major Arcana, representing new beginnings, innocence, spontaneity, and a leap of faith. The Fool's journey through all 22 Major Arcana cards is a metaphor for the soul's path through life's lessons. It is both the first and last card — the eternal beginner.

Card XVIII (18) of the Major Arcana. Depicts the moon illuminating a mysterious landscape, representing intuition, illusion, the subconscious, and the liminal space between the known and unknown. It warns that things may not be as they seem and invites trust in inner knowing over rational appearances.

Card XVII (17) of the Major Arcana. Symbolizes hope, renewal, serenity, and spiritual guidance. A figure pours water onto land and into a pool, representing the flow between the conscious and subconscious. It appears after the destruction of The Tower, offering healing.

Card XIX (19) of the Major Arcana. A card of joy, success, vitality, and clarity. It often follows The Moon, representing the emergence from confusion into understanding. The Sun illuminates truth and brings warmth after a period of darkness or uncertainty.

Card XVI (16) of the Major Arcana. Represents sudden upheaval, revelation, and the destruction of false structures. Lightning strikes a tower, shattering illusions and forcing truth to the surface. Though alarming, The Tower clears the way for The Star's healing.

Card XXI (21) of the Major Arcana and the final numbered card. Represents completion, integration, accomplishment, and wholeness. It marks the end of The Fool's Journey — all lessons have been learned, all elements united. The cycle then begins anew.

The lunar phase when the opposite half of the Moon is illuminated compared to the First Quarter, occurring about three weeks after the New Moon. Also called the Last Quarter.

The most fundamental tarot spread: three cards drawn to represent past, present, and future — or alternatively, situation, challenge, and advice. Its simplicity makes it ideal for daily practice, quick questions, and beginners learning card relationships.

The gravitational effect of the Moon (and Sun) on Earth, caused by the difference in gravitational pull across Earth's diameter. Tidal forces create ocean tides and may influence biological processes. The Moon's tidal force is about 2.2 times stronger than the Sun's despite the Sun's much greater mass, because tidal force depends on proximity.

Celestial coordinates calculated from the observer's actual location on Earth's surface rather than from Earth's center. Topocentric correction is vital for lunar astrometry due to significant lunar parallax (up to ~1°).

The passage of a celestial body through a zodiac sign or across a specific point. The Moon transits through all 12 signs in approximately 27.3 days, spending about 2.5 days in each sign.

An aspect formed when two celestial bodies are 120° apart, typically in signs of the same element. Trines represent ease, flow, and natural talent — energy moves smoothly between the planets. Often considered the most harmonious aspect, though it can sometimes indicate complacency because things come too easily.

A group of three zodiac signs that share the same element. Fire triplicity: Aries, Leo, Sagittarius. Earth: Taurus, Virgo, Capricorn. Air: Gemini, Libra, Aquarius. Water: Cancer, Scorpio, Pisces.

The zodiac system used in Western astrology, anchored to the vernal equinox (0° Aries). It divides the ecliptic into 12 equal 30° signs aligned with Earth's seasons rather than the constellations.

The darkest, innermost part of a shadow where the light source is completely blocked. During a total lunar eclipse, the Moon passes through Earth's umbra, turning deep red.

The period between the Moon's last major aspect to a planet and its entry into the next zodiac sign. Traditionally considered an unfavorable time for initiating new projects, as actions taken during this window may not produce lasting results.

The period when the Moon's illuminated portion is decreasing, from Full Moon to New Moon. The left side remains lit longest.

The period when the Moon's illuminated portion is increasing, from New Moon to Full Moon. The right side of the Moon (in the Northern Hemisphere) lights up first.

The foundational principle of lunar gardening: plant above-ground crops during the waxing moon (New Moon → Full Moon) when rising sap and increasing light favor upward growth, and plant below-ground crops during the waning moon (Full Moon → New Moon) when energy draws downward into roots. Pruning and harvesting are also timed to the waning phase.

A belt of 12 constellations along the ecliptic through which the Sun, Moon, and planets appear to travel. The Tropical zodiac (used in Western astrology) is based on the seasons; the Sidereal zodiac (used in Vedic astrology) is based on the actual star positions.