Equinox, or Equilux?

Equinox, or Equilux: Seasons Courtesy NASA https://www.weather.gov/dvn/Climate_Astronomical_Seasons
Courtesy NASA
We raced west toward home from the high plains, trying to beat the heavy snow that had been forecasted for Labor Day evening. Finally in the canyon—the revelation that seasons had passed while we were away. Temperatures plummeted, and the forests reacted. Favorite stands of aspens were already aglow above that familiar bend in the river. Meteorological fall had promptly arrived.

Its astronomical counterpart—the autumnal equinox—is a bit of a misnomer. The word equinox is our late Middle English iteration of the Latin term for “equal night,” but, astronomically speaking, this isn’t exactly true. The equinox is the single moment when the Earth’s axis is pointing neither toward nor away from the sun, providing entire hemispheres equal portions of light. This year’s autumnal equinox occurs at precisely 7:30 AM on Tuesday, September 22nd, and though daylight and night will share almost equal portions of the clock that day, they don’t split it evenly until two or three days later on what is called the ‘equilux’, meaning “equal light.”

Earth Orbit - With Date Spans, Courtesy National Weather Service (NWS)
Earth Orbit – With Date Spans
Courtesy National Weather Service (NWS)
It works like this. We count daytime from the moment the sun peeks above the horizon to the moment it sinks below. But, of course, the sun isn’t a light switch. We have several minutes of twilight before the sun rises and after it sets thanks to the lens-like refraction provided by our atmosphere. So, on the day of the equinox, those several minutes of twilight before sunrise and after sunset offset the equal exposure of the sun’s rays to our hemisphere by a small margin, giving us a tad more daylight than night. The equilux has to wait for Earth’s tilt to allow darkness to catch up.

But wait. It gets a little more complicated. Because the Earth’s axis begins tilting away from the sun immediately following the autumnal equinox (or toward it following the vernal equinox), different latitudes will experience the equilux at different intervals. As a rule, the closer one is to the equator, the longer they will wait for the equilux to occur in the fall and the sooner it will arrive in the spring. That is, unless you live within 5 latitudinal degrees of the equator. Then, sadly, you don’t get an equilux at all, ever, because you always have more than twelve hours of daylight.

Depending on where you live here in Utah, you will experience the equilux sometime on September 25th or 26th. So, this week, take out your stopwatch, and turn your eyes skyward.

I’m Josh Boling, and I’m Wild About Utah!

Photos: Courtesy Weather.gov, US National Weather Service(NWS), https://www.weather.gov/dvn/Climate_Astronomical_Seasons
Photos: Courtesy
Sound: Courtesy & Copyright Friend Weller, Utah Public Radio
Text: Josh Boling, 2020

Sources & Additional Reading

The Equinox Isn’t What You Think It Is, PBS Digital Studios, https://www.youtube.com/watch?v=MVDCsXUygEw

Kher, Aparna, Equinox: Equal Day and Night, Almost, https://www.timeanddate.com/astronomy/equinox-not-equal.html

City of North Logan, Utah, USA — Sunrise, Sunset, and Daylength, September 2020, Time and Date AS, https://www.timeanddate.com/sun/@7173983

Seasons, SciJinks, Jet Propulsion Laboratory, https://scijinks.gov/review/solstice/seasons/

Which Pole is Colder?, Climate Kids, The Earth Science Communications Team, NASA’s Jet Propulsion Laboratory, California Institute of Technology, https://climatekids.nasa.gov/polar-temperatures/

Earth’s Seasons – Equinoxes and Solstices – 2018-2025, The U.S. Naval Observatory, Astronomical Applications Department, https://www.weather.gov/media/ind/seasons.pdf

Changing seasons, Climate Resource Collections, National Oceanic and Atmospheric Administration, https://www.noaa.gov/education/resource-collections/climate/changing-seasons

Boling, Josh, A Solstice Vignette, Wild About Utah, December 16, 2019, https://wildaboututah.org/a-solstice-vignette/

Equinoxes, National Geographic, https://youtu.be/kaG6PTVrFP4

What is an Equinox? National Geographic, https://youtu.be/enlih8M5DN0

The Autumnal Equinox is Near, Watch the Skies Blog, NASA, https://blogs.nasa.gov/Watch_the_Skies/tag/equinox/

A Solstice Vignette

Winter Trail Courtesy Pixabay
Winter Trail
Courtesy Pixabay
In the frigid dark of long winter nights, we tell stories—stories of thievery, heroism, and light. Raven, Maui, and Koo-loó-pe, the hummingbird. They are all said to have taken back the sun from too much darkness for their people, and their deeds remain the whispered subjects around campfires that lead up to the winter solstice. I’d like to tell a story of my own about our calendar’s longest, darkest night and our relationship with it.

The first archaeological evidence we have that point to organized observances of the winter solstice come from the Neolithic period—that era from about 12,000 to 6,500 years ago which hastened the Stone Age into those of Copper and Bronze. The Neolithic coincided with the invention of farming in the Near East; and on the heels of farming came the necessity of a calendar, upon which the new agrarian economy was utterly dependent—for delineating seasons, planting and harvesting crops, and monitoring food stores over winter. We looked to the sky, of course, as we always had, for such insights into the survival of our species. We found familiar patterns there—the ebb and flow of darkness and light that came with the ever changing arc of the sun. From north to south the sun wanders, from light to dark and warm to cold. We built shrines to its movement. You know their names: Stonehenge and Newgrange; the Goseck circle and Chaco Canyon’s sun dagger. Each culture would create its own method of tracking, observing, and then of celebrating. We built tools, and then shrines, and then we built mythology.

The Neolithic agrarian economy lived by the sun. As darkness fell on wintery fields, our Stone Age ancestors shared stories about that moment when the light would return, hoping that their characters could hasten the sun. Reverence is a powerful thing. It informs the stories we tell about ourselves–stories of existence balanced on moments. We revere the return of the light when the night is at its darkest and longest. That’s when we send Raven, Maui, or an exuberant Miwok hummingbird to bring the sun back from too much darkness. That’s the mythology, at least.

A Solstice Vignette: The Seasons Courtesy US NWS
The Seasons
Courtesy US NWS
Astronomically speaking, the winter solstice is ephemeral. In the northern hemisphere, it occurs at the exact moment when the northern portion of the Earth’s axis is tilted directly away from the sun at its farthest point. This year, in the Mountain West, that moment is Saturday, December 21st, at 9:19pm. But astronomy’s geometries and physics are only part of the tale. Our stories are told with an affinity for more than just practical science.

Solstice means “to be still,” to wait for the return of the light. We attach great meaning to it. The cluster of holidays we have in winter worldwide are evidence enough of that. Every culture recognizes, in its own way, the vast significance of this fleeting moment; and those observances connect us through time to the ancestors that first looked up—marking time, checking dates, counting bushels until the next harvest. The solstice is a moment we barely notice, but one that bears immense anticipation. We move right through it at the speed of time—then tell our stories to lend meaning to that time spent moving, from the light through to darkness and back again.

I’m Josh Boling, and I’m Wild About Utah!

Photos: Courtesy US NWS
Photos: Courtesy Pixabay, https://pixabay.com/photos/snow-weather-trail-winter-autumn-834111/
Sound: Courtesy & Copyright Josh Boling & Friend Weller
Text: Josh Boling, 2018

Sources & Additional Reading

Astronomy Picture of the Day, NASA, https://apod.nasa.gov/apod/ap071222.html

Solstices & Equinoxes for Ogden (Surrounding 10 Years), TimeandDate.com, https://www.timeanddate.com/calendar/seasons.html?n=4975

Byrd, Deborah, All you need to know: December solstice, EarthSky.org, Dec 15, 2019, https://earthsky.org/astronomy-essentials/everything-you-need-to-know-december-solstice

Natural Quiet and Darkness in our National Parks

Natural Quiet and Darkness in our National Parks: View looking east in early summer from Cedar Breaks National Monument Courtesy US NPS, Zach Schierl, Photographer
View looking east in early summer from Cedar Breaks National Monument
Courtesy US NPS, Zach Schierl, Photographer
If visitors find locations in Utah’s National Parks, where very little man-made sounds are heard, it can be a breathtaking experience. A park visitor may canoe along riparian habitat and hear a variety of bird calls, or hike a trail and come around a bend to see a few deer jump over the sage-brush.

These types of experiences may also occur after dark when visitors participate in stargazing or a full-moon hikes.

The southern Milky Way visible during a star party at Cedar Breaks National Monument. We use red lights on the telescopes during star parties to help preserve night vision. Courtesy US NPS, Zach Schierl, Photographer
The southern Milky Way visible during a star party at Cedar Breaks National Monument. We use red lights on the telescopes during star parties to help preserve night vision.
Courtesy US NPS, Zach Schierl, Photographer
Mark and Sallie Shelton said, “Utah dark skies are our passion! The [dark] sky and quiet solitude are magical. Visitors, from around the world, are in awe when they get their first [heavenly] glimpse of [the Milky Way] and see the stars shining like diamonds on dark velvet.”

Protecting the quiet and darkness of our National Parks has become a priority for many managers and researchers.

Four planets and the Moon are visible in the twilight sky over ancient Bristlecone Pine trees at Cedar Breaks NM Courtesy US NPS, Zach Schierl, Photographer
Four planets and the Moon are visible in the twilight sky over ancient Bristlecone Pine trees at Cedar Breaks NM
Courtesy US NPS, Zach Schierl, Photographer
Christopher Monz, professor in the Department of Environment and Society in the Quinney College of Natural Resource at USU joined with five other scientists who have all worked on issues of noise pollution and light pollution to compile the book, “Natural Quiet and Natural Darkness: The “New” Resources of the National Park.”
title=”Four planets and the Moon are visible in the twilight sky over ancient Bristlecone Pine trees at Cedar Breaks NM Courtesy US NPS, Zach Schierl, Photographer”
The Summer Milky Way as seen from Point Supreme at Cedar Breaks NM. The landscape is illuminated by the light of a 1st Quarter moon. Courtesy US NPS, Zach Schierl, Photographer
The Summer Milky Way as seen from Point Supreme at Cedar Breaks NM. The landscape is illuminated by the light of a 1st Quarter moon.
Courtesy US NPS, Zach Schierl, Photographer
Monz explains, “[We wanted] to compile, in one place, the best science on both the social and ecological dimensions regarding the importance of the resources of darkness and quiet, and the consequences of them slowly disappearing in our most precious protected areas – the national parks.”

The book gathered many interesting findings.

Visitors enjoying a quiet day at Hovenweep National Monument Courtesy & Copyright Shauna Leavitt
Visitors enjoying a quiet day at Hovenweep National Monument
Courtesy & Copyright Shauna Leavitt
One is the concept of “listening area” which is the distance an individual (human or animal) can hear normal sounds and calls that they’re evolved and adapted to. For a bird species it might be a mating call, for deer it might an alert response from a predator.

As noise increases the listening area may decrease dramatically.

Monz said, “In the United States noise from roads has increased three fold since 1970.”

A three decibel increase in noise results in a 50 percent decrease in listening area. If there is a 10 decibel increase, the result is a staggering 90 percent decrease in listening area.

Monz explains, “If you put noise into the environment there is the potential for significant ecological implications, particularly for wildlife. They can no longer be reliant on the sense of hearing to carry out normal activities…some species will move out of those noisy areas to quieter environments which creates a displacement effect.”

For humans, this means we have less opportunities to engage with the sights and sounds of nature.

One success story outlined in the book occurred in Muir Woods National Monument in California. Monz said, “Simply by putting up signs which raised the visitor’s awareness of the environment they were in, and the importance of quiet for other visitors, the noise decreased by 2 decibels. This gave folks an opportunity to experience better natural quiet environment and a little bit more biodiversity from the standpoint of hearing bird calls from the surrounding forest.”

The book also provides ideas for managing the resource of darkness in the National parks.

Guests enjoying Arches National Park Courtesy & Copyright Shauna Leavitt
Guests enjoying Arches National Park
Courtesy & Copyright Shauna Leavitt
Monz said, “Right now 80% of the world’s population lives in locations where there is some compromise of natural darkness…most will never see the Milky Way.”

Cedar Breaks National Monument, which has the highest star gazing site at 10,500 feet, received an award from The International-Dark Sky Association (IDA) for preserving its Dark skies.

The authors of “Natural Quiet and Natural Darkness” hope the book will get in the right hands to provide park managers with this easily accessible tool where they can find the best science and actionable ideas to increase quiet and darkness in our National Parks.

This is Shauna Leavitt and I’m Wild About Utah.

Natural Quiet and Darkness in our National Parks-Credits:
    Courtesy US NPS, Zach Schierl, Photographer, Education Specialist, Cedar Breaks National Monument
    Courtesy & Copyright Shauna Leavitt,
Audio: Courtesy and Copyright
Text: Shauna Leavitt, Utah Cooperative Fish and Wildlife Research Unit, Quinney College of Natural Resources, Utah State University

Natural Quiet and Darkness in our National Parks-Additional Reading

Experience Dark Night Skies, Cedar Breaks National Monument, US National Park Service, https://www.nps.gov/cebr/planyourvisit/experience-dark-night-skies.htm

Cedar Breaks National Monument Designated as an International Dark Sky Park, https://www.nps.gov/cebr/learn/news/cedar-breaks-national-monument-designated-as-an-international-dark-sky-park.htm

Burkitt, Bree, Cedar Breaks recognized as Dark Sky Park, The Spectrum, https://www.thespectrum.com/story/news/local/cedar-city/2017/03/09/cedar-breaks-recognized-dark-sky-park/98980850/

Spotlight – The Cedar Breaks National Monument Master Astronomer Program, Colorado Plateau Dark Sky Cooperative, https://cpdarkskies.org/2018/10/17/spotlight-the-cedar-breaks-national-monument-master-astronomer-program/

Dark Skies

Delicate Arch at Night Courtesy National Park Service, Jacob W. Frank. Photographer
Delicate Arch at Night
Courtesy National Park Service, Jacob W. Frank. Photographer
The night sky…throughout history humans have looked up after the sun set in the evening and marveled at the astral bodies spread above them in a sea of black. This sight has inspired people from every age of history and from every culture around the world.

But it’s not the same as it used to be.

For most people, the cycles of night and day are so constant in our lives that we often take them for granted. The rising of the sun in the morning and its setting every evening molds our lives, and has for all of human history. The heavenly bodies we see above us, the sun, moon, planets, comets, and stars, influence all aspects of human civilization, from religion and philosophy to art and poetry. While daytime has remained constant from the beginning to the modern day, the same cannot be said for the night.

Until the end of the 19th century, the setting sun meant a world enveloped in darkness. The night was a time for retreat to homes and hearths, a respite in human activity until dawn. Try to imagine looking up into the night sky from the side of dying campfire ten thousand years ago, or from the step of a frontier cabin only two hundred years ago and seeing the moon and stars as the only source of light around you. Today this universal heritage is quickly being lost to the artificial light emitted by humans across the globe.

It may seem strange to think of darkness as a natural resource, but its importance to life on Earth cannot be overstated. Beyond humans, the billions of plants and animals across the planet have evolved over the eons to their own niche in the day-night cycle. Sunlight, or the lack of it, controls plant and animal behavior, from when to eat or sleep, when to migrate, where to travel to look for food, and even when to reproduce. The artificial light cast by cities disrupts these natural patterns for animals and can lead to hardship and death for many.

Efforts to reduce light pollution are picking up across the country and include everything from buildings and factories shutting off all non-essential lighting during animal migration seasons, to everyday citizens simply turning off outdoor lights when they go to bed.

Despite these efforts however, most Americans in the 21st century are still affected by at least some light pollution and many city-dwellers have never seen a truly dark night sky. Even for those living away from cities, a night sky might be interrupted by sky glow, a phenomenon that occurs when clouds scatter and reflect light back to earth.

Luckily for Utahns however, dark skies might be closer than you think. Utah is home to nine different “Dark Sky Parks”, certified by the International Dark-Sky Association. Among these places are Canyonlands and Capitol Reef National Parks; Natural Bridges, Hovenweep, and Cedar Breaks National Monuments; Dead Horse Point, Goblin Valley, and Antelope Island State Parks; as well as the North Fork area in Weber County. These dark sky parks offer a distinguished quality of starry nights and a nocturnal environment protected for future generations. So whether you are an astronomy enthusiast, an animal lover, or just want to see the night sky as our ancestors saw it for thousands of years, dark sky parks are the place for you.

Starry Night Vincent van Gogh Courtesy: Google Art Project
Starry Night
Vincent van Gogh
Courtesy: Google Art Project
As Vincent van Gogh, the mastermind behind the famous painting Starry Night once remarked, “For my part I know nothing with any certainty, but the sight of the stars makes me dream.”

For Wild About Utah, I’m Kajler Rask.

Photos: Courtesy National Park Service, Frank W. Jacobs, Photographer
Starry Night, Vincent van Gogh, Courtesy: Google Art Project
Text: Kajler Rask

Clear Sky Charts, Utah, Attilla Danko, ClearDarkSky.com, https://cleardarksky.com/csk/prov/Utah_charts.html

Utah Leads The World With Nine International Dark Sky Parks, International Dark-Sky Association, https://www.darksky.org/utah-leads-the-world-with-nine-international-dark-sky-parks/

Dark Sky Parks, Utah Office of Tourism, https://www.visitutah.com/things-to-do/dark-sky-parks

Top 5 Star Gazing Spots in Utah, Utah.com, Utah Travel Industry Website, https://utah.com/article/top-5-star-gazing-spots

Eyes In The Sky: Exploring Global Light Pollution With Satellite Maps, International Dark-Sky Association, https://www.darksky.org/eyes-in-the-sky-exploring-global-light-pollution-with-satellite-maps/

Dark Skies, Antelope Island State Park, https://stateparks.utah.gov/parks/antelope-island/dark-skies/

Utah State Parks Dark Skies Program, State Parks, Utah Department of Natural Resources, https://stateparks.utah.gov/resources/utah-state-parks-dark-sky-initiative/

Stargazing, Arches National Park, https://www.nps.gov/arch/planyourvisit/stargazing.htm

Lightscape / Night Sky, Arches National Park, https://www.nps.gov/arch/learn/nature/lightscape.htm

Night Skies, Natural Bridges National Monument, https://www.nps.gov/nabr/learn/nature/darkskypark.htm

Marc Toso, AncientSkys.com, https://www.ancientskys.com/

Experience the Magic of the Stars at Utah’s State Parks, Utah State Parks Blog, State of Utah, April 13, 2023, https://stateparks.utah.gov/2023/04/13/experience-the-magic-of-the-stars-at-utahs-state-parks/