The Fall Equinox

🔮 NERD_FILES // DEEP_DIVE

Hello My Love Bugs! 

Happy Fall Equinox! Today at 8:05PM EST the Sun will enter Libra marking the start of the Fall Equinox for our 2026 Sun rotation.  In this post I want to deep dive the history & importance of the Fall Equinox across time & space. 

Science Behind The Equinox

During the autumnal equinox, the Earth' axial tilt points neither toward nor away from the sun. The Earth orbits the sun at a fixed 23.5 degree tilt. During Solicties, one hemisphere tilts directly toward the sun, while the other tilts away. During, an Equinox, the Earth reaches  a position in its orbit where its rotational axis is perpendicular to the incoming solar rays.  

The word equinox comes from the latin word "equi" meaning equal & the latin word "nox" meaning night. Equinox translates to "Equal Night". When the Sun enters Libra the night & day become equal to each other. On the day of the fall equinox, almost everywhere in the WORLD will experience 12 hours of light & 12 hours of darkness. A true harmonic balance. 

At 12:00PM noon today the sun will pass over the subsolar point also known as the equator & provide direct light. Only during the equinox does the sun rise directly in the east side & sets directly in the west side, everywhere on Earth but for the North & South poles. 

On this day, is the start of the "reversal of seasons" for the northern & southern hemispheres of the Earth. In the northern hemisphere it marks the official astronomical start of autumn. Days begin growing progressively shorter than nights until the winter solstice in December. For the southern Hemisphere it marks the official start of spring (vernal equinox). Days begin growing longer than the nights until the summer solstice in December. 

& Finally the sun shifts for the north & south pole. The north pole will experience its final sunset before entering a six month period of polar night. While the south pole sees its first sunrise, starting its six months of continuous light. 

Ancient History & Traditions Of The Equinox 

In antiquity, the fall equinox was far more than a harvest festival - it was a deeply spiritual threshold. It marked the moment where light yielded to darkness, initiating mystery tied to death, rebirth, underworld deities, & precise astronomical alignments built directly into stone architecture. 

The Eleusinian Mysteries (Ancient Greece) 

Held around the autumn equinox, this was the most famous secret religious rite of ancient Greece. Ininitates walked from Athens to Eleusis to reenact the myth of Demeter (goddess of agriculture) grieving her daughter Persephone descended into the underworld for six months with Hades, symbolizing the death of crops & the onset of autumn.

Ancient Celtic Harvest Rites & Mabon Origins

Before organized Druidic traditions were codified, ancient Celtic peoples celebrated the Second Harvest. Farmers offered their last sheaves of grains & ripe fruits to the spirits of the land. It was a time to balance accounts, slaughter livestock that could not be feed through the winter, & prepare stored foods. 

Mesoamerican Solar Alignments (Maya & Olmec)

Ancient Mesoamerican civilizations constructed their ceremonial complexes to align precisely with the equinox sunrise & sunset. At Chichen Itza, the shadow of the feathered serpent god Kukulkan slithers down the pyramid staircase, signaling to the farmers that it was time to harvest corn & prepare for the dry season. 

The Egyptian Ritual Of Divine Scales

In Ancient Egypt, the equinox - when the day & night were in total equilibrium - was symbolically linked to Ma'at, The goddess of balance, truth, & cosmic order. It was viewed as a sacred time for inner reflection, balancing personal actions before the deity Anubis weighed the human heart against a feather. 

Ancient Persian Harvest Rites (Mehregan) 

Dating back over 3000 years to Zoroastrian times, Mehregan was celebrated during the autumnal equinox in honor of Mithra (god of light, friendship, & covenants). Kings & commoners wore purple robes, drank wine, & shared autumn fruits like pomegranate, apples, & nuts to celebrate the victory of light over seasonal darkness. 

The Shift In Brain Chemistry 

The fall equinox acts a  biological pivot point for human physiology. Humans are heavily regulated by light, & the sharp decline in photoperiod (daylength) that accelerates right around the equinox triggers measures shifts in our brain chemistry, hormones, sleep, & mood.  

Melatonin Oversupply. Melatonin is the hormone responsible for signaling sleepiness, & triggered by darkness. As the night length overtakes the daylight following the fall equinox, the pineal gland produces melatonin earlier in the evening & for longer durations. This can cause daytime grogginess, brain fog, & difficulty waking up in the mornings. 

Serotonin Dips: Serotonin is the key neurotransmitter for regulating mood, focus, & appetite. It's also driven by sunlight exposure. (We are quite similar to plants). Reduced natural light triggers a drop in serotonin production. Lower serotonin levels combined with evolutionary conservation signals cause the brain to seek quick dopamine and serotonin boosts. This manifests as intense cravings for carbohydrate-rich and sugary foods ("foraging/hibernation mode").

Circadian Misalignment: The master pacemaker in the brain, the (suprachiasmatic nucleus or SCN), relies of morning sunlight to synchronize our internal 24-hour clock. When daylight rapidly shortens around the equinox, the internal circadian rhythm desynchronizes from social schedules, creating a state similar to mild jet lag. 

Decreased Vitamin D Synthesis: Sunlight triggers the skin to synthesis vitamin D, which acts as an essential pro-hormone for brain health & serotonin synthesis. Exposure begins dropping steeply post-equinox, leading to lower energy & reduced immune function.

[Equinox Transition] ──► Reduced Daylight ──► Lower Serotonin + Higher Melatonin ──► Mood/Energy Drop

For roughly 5% of the population, the biochemical shift triggers SAD—a form of major depressive disorder with a seasonal pattern. An additional 10–20% experience mild "autumnal blues" marked by lower motivation and social withdrawal. Socially and behaviorally, the shift from long outdoor summer days to darker evenings prompts an inward, home-focused mindset. People naturally spend more time indoors, which can increase feelings of isolation if not intentionally managed. This is the time to choose you, do something for yourself every single day, even if its small. 

Many evolutionary biologists view these changes as an ancient survival mechanism. In pre-industrial human history, the biological shift following the fall equinox encouraged energy conservation, increased fat storage via carb consumption, and reduced exposure to harsh outdoor elements during the incoming cold months.

As the daylight wanes and our circadian rhythms naturally nudge us toward rest, give yourself permission to slow down. The equinox isn't just an astronomical date—it’s a cue to turn inward and reset.

How are you marking the start of the season this year—watching the night sky, making a favorite warm meal, or simply taking a moment to breathe in the crisp air? Drop a comment below and let me know!

XoXo, 

Abby

Hello My Love Bugs! 

Happy Fall Equinox! Today at 8:05PM EST the Sun will enter Libra marking the start of the Fall Equinox for our 2026 Sun rotation.  In this post I want to deep dive the history & importance of the Fall Equinox across time & space. 

Science Behind The Equinox

During the autumnal equinox, the Earth' axial tilt points neither toward nor away from the sun. The Earth orbits the sun at a fixed 23.5 degree tilt. During Solicties, one hemisphere tilts directly toward the sun, while the other tilts away. During, an Equinox, the Earth reaches  a position in its orbit where its rotational axis is perpendicular to the incoming solar rays.  

The word equinox comes from the latin word "equi" meaning equal & the latin word "nox" meaning night. Equinox translates to "Equal Night". When the Sun enters Libra the night & day become equal to each other. On the day of the fall equinox, almost everywhere in the WORLD will experience 12 hours of light & 12 hours of darkness. A true harmonic balance. 

At 12:00PM noon today the sun will pass over the subsolar point also known as the equator & provide direct light. Only during the equinox does the sun rise directly in the east side & sets directly in the west side, everywhere on Earth but for the North & South poles. 

On this day, is the start of the "reversal of seasons" for the northern & southern hemispheres of the Earth. In the northern hemisphere it marks the official astronomical start of autumn. Days begin growing progressively shorter than nights until the winter solstice in December. For the southern Hemisphere it marks the official start of spring (vernal equinox). Days begin growing longer than the nights until the summer solstice in December. 

& Finally the sun shifts for the north & south pole. The north pole will experience its final sunset before entering a six month period of polar night. While the south pole sees its first sunrise, starting its six months of continuous light. 

Ancient History & Traditions Of The Equinox 

In antiquity, the fall equinox was far more than a harvest festival - it was a deeply spiritual threshold. It marked the moment where light yielded to darkness, initiating mystery tied to death, rebirth, underworld deities, & precise astronomical alignments built directly into stone architecture. 

The Eleusinian Mysteries (Ancient Greece) 

Held around the autumn equinox, this was the most famous secret religious rite of ancient Greece. Ininitates walked from Athens to Eleusis to reenact the myth of Demeter (goddess of agriculture) grieving her daughter Persephone descended into the underworld for six months with Hades, symbolizing the death of crops & the onset of autumn.

Ancient Celtic Harvest Rites & Mabon Origins

Before organized Druidic traditions were codified, ancient Celtic peoples celebrated the Second Harvest. Farmers offered their last sheaves of grains & ripe fruits to the spirits of the land. It was a time to balance accounts, slaughter livestock that could not be feed through the winter, & prepare stored foods. 

Mesoamerican Solar Alignments (Maya & Olmec)

Ancient Mesoamerican civilizations constructed their ceremonial complexes to align precisely with the equinox sunrise & sunset. At Chichen Itza, the shadow of the feathered serpent god Kukulkan slithers down the pyramid staircase, signaling to the farmers that it was time to harvest corn & prepare for the dry season. 

The Egyptian Ritual Of Divine Scales

In Ancient Egypt, the equinox - when the day & night were in total equilibrium - was symbolically linked to Ma'at, The goddess of balance, truth, & cosmic order. It was viewed as a sacred time for inner reflection, balancing personal actions before the deity Anubis weighed the human heart against a feather. 

Ancient Persian Harvest Rites (Mehregan) 

Dating back over 3000 years to Zoroastrian times, Mehregan was celebrated during the autumnal equinox in honor of Mithra (god of light, friendship, & covenants). Kings & commoners wore purple robes, drank wine, & shared autumn fruits like pomegranate, apples, & nuts to celebrate the victory of light over seasonal darkness. 

The Shift In Brain Chemistry 

The fall equinox acts a  biological pivot point for human physiology. Humans are heavily regulated by light, & the sharp decline in photoperiod (daylength) that accelerates right around the equinox triggers measures shifts in our brain chemistry, hormones, sleep, & mood.  

Melatonin Oversupply. Melatonin is the hormone responsible for signaling sleepiness, & triggered by darkness. As the night length overtakes the daylight following the fall equinox, the pineal gland produces melatonin earlier in the evening & for longer durations. This can cause daytime grogginess, brain fog, & difficulty waking up in the mornings. 

Serotonin Dips: Serotonin is the key neurotransmitter for regulating mood, focus, & appetite. It's also driven by sunlight exposure. (We are quite similar to plants). Reduced natural light triggers a drop in serotonin production. Lower serotonin levels combined with evolutionary conservation signals cause the brain to seek quick dopamine and serotonin boosts. This manifests as intense cravings for carbohydrate-rich and sugary foods ("foraging/hibernation mode").

Circadian Misalignment: The master pacemaker in the brain, the (suprachiasmatic nucleus or SCN), relies of morning sunlight to synchronize our internal 24-hour clock. When daylight rapidly shortens around the equinox, the internal circadian rhythm desynchronizes from social schedules, creating a state similar to mild jet lag. 

Decreased Vitamin D Synthesis: Sunlight triggers the skin to synthesis vitamin D, which acts as an essential pro-hormone for brain health & serotonin synthesis. Exposure begins dropping steeply post-equinox, leading to lower energy & reduced immune function.

[Equinox Transition] ──► Reduced Daylight ──► Lower Serotonin + Higher Melatonin ──► Mood/Energy Drop

For roughly 5% of the population, the biochemical shift triggers SAD—a form of major depressive disorder with a seasonal pattern. An additional 10–20% experience mild "autumnal blues" marked by lower motivation and social withdrawal. Socially and behaviorally, the shift from long outdoor summer days to darker evenings prompts an inward, home-focused mindset. People naturally spend more time indoors, which can increase feelings of isolation if not intentionally managed. This is the time to choose you, do something for yourself every single day, even if its small. 

Many evolutionary biologists view these changes as an ancient survival mechanism. In pre-industrial human history, the biological shift following the fall equinox encouraged energy conservation, increased fat storage via carb consumption, and reduced exposure to harsh outdoor elements during the incoming cold months.

As the daylight wanes and our circadian rhythms naturally nudge us toward rest, give yourself permission to slow down. The equinox isn't just an astronomical date—it’s a cue to turn inward and reset.

How are you marking the start of the season this year—watching the night sky, making a favorite warm meal, or simply taking a moment to breathe in the crisp air? Drop a comment below and let me know!

XoXo, 

Abby