Seeing Stars Blog

Seeing Stars, a blog by Susan Cushing, a Master Naturalist, astro-educator, amateur astronomer,  and ‘Night Naturalist’ explores our night sky and what our ‘neighbors’ -the animals, birds, insects and plants- are doing between dusk and dawn. Susan's blog also explores how our artificial light affects the world around us and simple, safe ways we can protect and enjoy our dark skies.

Current Blog

December 8, 2025   A Perspective From A Space Ship

Going to Mars with a few coworkers is a complicated, multi-year endeavor. Encapsulated in a tiny space ship together, a half dozen humans have to perform optimally, without lapses. They must constantly cooperate in sharing space, making decisions, and communicating. They also must be good tempered and flexible. What mix of people would work best in this situation?

It’s easy to assume people that are as similar as possible would get along together best. But that may not be true. Isa Pener and Hao Chen of the Stevens Institute of Technology in the US recently studied how personality traits influence stress responses and resilience over long duration missions. 

They found that teams with variations in personality traits, especially those combining high conscientiousness with low neuroticism, high extroversion and high agreeableness functioned with less stress, better cohesion, better health outcomes and overall improved performance. They concluded a wide range of coping styles and interpersonal dynamics was likely to maintain crew stability over time.

There isn’t much room for error in a trip to Mars. Everything has to work, all the time. Could the lessons learned and the strategies chosen for space travel be useful on earth, in our homes and communities where getting along and taking care of the world around us is critical for life here too?

Astronauts now in space are from many countries. Women and men share mission responsibilities. Astronauts returning from space often speak of new feelings of empathy and gratitude for all life on earth and an awareness of how rare and beautiful our tiny world is.

Our world is becoming more crowded, our resources depleted. Lessons from space travel could be useful for optimizing life on earth as well as life in space.

Past Blogs

December 1, 2025   The Best Gifts   

The best gifts are sharing what we love with someone else.  Regularly sharing a walk together to enjoy the new snowfall or the sunset has been something people used to do but now we often forget the pleasure it can be. This holiday season try giving the gift of your time and the opportunity to enjoy the free gifts of Nature.

A gift to a friend or relative of sharing a walk in the woods or on one of our many beautiful park trails once a month or once a week, to watch the sunset or the moonrise might give each of you experiences to remember. Sharing time as the sun sets and the stars come out overhead makes us feel happy. Why sit watching a glaring screen? Sharing the effort to put on your coats and go outside could bring more benefits than you can count.

I’m an advocate for walking at night. We are all too busy and spend too much time facing those hopeless little screens. The evening sky and the starry night will slow you down. Sunsets are designed to calm and relax anyone in their presence. Add the sound of an owl calling and a peaceful evening is complete. Walking renews our energy while calming stress. Walking in the evening or the night is an antidote to the hurry of our days. Share this with a friend and double the pleasures.

If you’d like to give a present you can wrap, a pair of binoculars for seeing stars as well as birds, or a planisphere to locate constellations are inexpensive and useful gifts. Make more good memories this holiday; it’s a gift that returns as much as you give.  (back)

November 24, 2025   Mayan Astronomy    

The Mayan Civilization in Central America thrived between approximately 2000BC and 1500CE. It was one of the most advanced of ancient societies, especially in astronomy and mathematics. To this day we don’t understand how they made their calendars and mathematical calculations. Mayans had a calendar system that included a 405 month lunar calendar, a 365 day solar calendar, a 260 day divination calendar, a Long Count system for tracking very long into the past or future, an 819 day Count of unknown use, and repeating sets of nine days related to the ‘Nine Lords of the Night’. They knew exactly when eclipses and other astronomical events would occur, far into the future.

With nothing but their observational and memory skills far beyond anything we now are capable of, the Mayans developed and maintained these intricate systems and used them for hundreds of years. Slowly we have parsed out partial understandings of their knowledge and methods but even with all our technology we have incomplete knowledge of how they developed their understanding of time, the movement of sun, moon, and stars and the tools to translate that into complex mathematics. 

The dark night full of stars always in motion, and the relation of the sky to the animals and life cycles on earth was not feared but seen as a source of vital information for humans. The night was a significant part of their lives. What was their experience of the night like? They must have also appreciated the beauty and spectacle of a sky more dark and clear than we have ever seen.  

The next time you gaze up at the stars, imagine the night sky as a vast library of information about how the world and the universe works. It’s all still there for us to explore and enjoy as the Mayans did so long ago.

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November 17, 2025   Winter Stargazing

As winter approaches the sky is often less hazy making this season a great time to stargaze. So grab a warm jacket and head outside around sunset. Walk or sit for a while to watch the sky colors change. If it is clear the eastern horizon will be blue and indigo and the western horizon will have red and orange colors. Where in the sky do you see the first star appear? 

As darkness replaces colors in the sky winter constellations start to be visible. Through the winter they rise earlier each month. Orion, Cassiopeia, Gemini, and the bright stars Capella, Sirius, Castor and Pollux shine high overhead. The Andromeda Galaxy is visible, the only galaxy we can see with the naked eye. The beautiful Pleiades or Seven Sisters star cluster shines above Orion. This is maybe the most beautiful cluster of stars to view with your binoculars.

It’s fun to figure out what constellation that first star belongs to, before the other stars fill in the picture. Sometimes the first bright object is a planet. 

In the next few weeks of early winter there are eight meteor showers. Regular night sky viewers are likely to see a few ‘falling stars’. The Orion Nebula is in the best position for good binocular viewing and with shorter days the full moon rising at sunset is easier to see than at any other time of year.

You can stand in your driveway and see some of the beauty of these winter nights, but getting out for an early evening walk on the Old 131 Trail at the Kickapoo Valley Reserve or on a quiet country road will be worth your time. For guided starry sky walks check with info@4darkskies.org. The magic is always there, under a starry sky. Come out and find it for yourself. (back)

November 10, 2025   Owl Flight

An owl glides across the meadow on a dark night. Why do they fly silently and other birds do not?

Krista Le Piane at the University of California wondered if owls fly silently so that they can better hear where their next meal is located in the dark, or do they fly silently so that their prey cannot hear them coming? Here’s what she learned.

The leading edge of an owl feather has small serrations, and the trailing edge is slightly fringed. If you’ve ever held an owl feather, you know it feels like velvet. Each of these features break up the air flow over the owl’s wings, dampening the sound.

Owls live on every continent but Antarctica, and eat many kinds of prey. Le Piane examined feathers from seventy species of owls and compared the feather structure to the diets of the owls.  

The owls that eat fish that cannot hear them coming, or insects that don’t hear well, have less serrations and fringes on their feathers. Their wings make more sound as they fly. The Tawny Fish Owl of Southeast Asia and the Burrowing Owls of the Southwest U.S. who eat insects have smooth feather edges. Owls that hunt mammals with good hearing have more sound dampening structures on their feathers. The Barred Owls, Great Horned Owls, Long Eared Owls and Screech Owls in our forests fly silently as they hunt small rodents in the meadows.

Night hunting owls depend more on sound control than day hunting owls that use their vision to find prey. Not all owls fly silently, and whether they hunt keen-eared mammals or not, hunt by sight during the day, or hunt by sound at night influences the structure and functions of each species’ feathers. As we learn how other species live in the world, we realize how complex and diverse they have to be to survive.  (back)

November 3, 2025   Our Towns Lead in Reducing Light Pollution

Information on the costs of light pollution has become available to everyone, inspiring communities, businesses and individuals all over the world to make improvements in lighting. In the recent year or so Ontario, Wildcat Mountain State Park, Esofea County Park, Norwalk, Wilton, and Organic Valley changed lighting to save money and reduce pollution.

In the past few months Cashton, La Farge, Viroqua and Westby have also joined municipalities across the nation in taking a proactive approach to improving nighttime lighting in their communities. Each of these communities has chosen streetlights with newly available 2200 Kelvin (K) fixtures, rather than typical 4000K fixtures. Kelvin (K) is the unit of measurement for the color temperature of light. 2200K lights omit much less blue light than 4000K. Blue light at night significantly increases glare and has been shown to have much greater negative effects on sleep quality, human health, and the environment. By choosing 2200K these communities can also decrease light pollution by 45% compared to 4000K streetlights. These fixtures feature a 10 year warranty and include dimmers which offer additional flexibility so the light level can be adjusted based on need. As a bonus, current energy incentives available to any Wisconsin municipality, including school districts, provide rapid paybacks on these improvements. There are even better incentives available for rural municipalities. For more information on these new streetlights and ways you can take action in your own community to improve nighttime lighting, reach out to Kickapoo Valley Dark Sky Initiative at info@4darkskies.org or check out their website at www.4darkskies.org.

Making lighting improvements now to use these temporary incentives puts money in your town’s pocket right away. Help our children see the stars as they grow up, and help your town get in on the savings that are part of better lighting. (back)

October 27, 2025   The Beaver Moon

The next full moon is on November 5th and it rises before 5pm so take a stroll with your friends and family to see one of Nature’s most beautiful sights. It’s free! No matter how many thousands of times the full moon has risen humans are still amazed by the sight. It’s worth the time to put on your jacket and take a walk.

The November full moon is a ‘perigean’ full moon, which means it is very close to Earth and may appear larger than usual in certain atmospheric conditions. It is traditionally called the Beaver Moon if it occurs after November 5th or the Hunters Moon if before then. Other names used for this moon are Whitefish Moon or Frost Moon by Indigenous peoples. In Japan, they say ‘Meigetsu Moon’, meaning ‘bright’ or ‘famous’ moon, to note that this fall moon holds special beauty worth observing.

We’re all familiar with the marks on the moon’s surface, and recognize either a face, or a rabbit, or a person carrying something on their back, depending on where you live in the world. These marks always look the same because the moon spins at a speed that matches its’ orbit around the earth. The same side of the moon always faces us. What do you see in the full moon?

Moonlight makes magic, and the full moon inspires birds to sing at night, poets to write poems, and people to fall in love. Moonlight illuminates our way and makes the dark night interesting and accessible. A dose of moonlight may relieve many woes and bring back forgotten pleasures that come only from the simple act of taking time to enjoy what Nature offers.

If staring at that lifeless screen does not warm your heart, go outside and watch the moon rise. Maybe you’ll even write a poem!   (back)

October 20, 2025   Jupiter’s Auroras

Did you know our Northern Lights, the aurora borealis, are not unique to earth? Venus, Mars, Saturn, Uranus, Neptune and Jupiter all have some form of aurora around their polar regions. If Mercury has aurora, we can’t see it because of its thick atmosphere. All aurora displays are formed by the same process as Earth’s auroras. Charged particles from the Sun bump into the gaseous molecules in the outer reaches of a planet’s atmosphere creating movement, heat and light. 

NASA’s Juno spacecraft has been orbiting over Jupiter’s poles since 2016, listening to electromagnetic signals made by plasma particles that create a unique aurora.

Jupiter has a magnetic field 20,000 times stronger than earth’s that causes particles to vibrate extremely slowly. The particles break apart in Jupiter’s strong energy field, becoming plasma which functions more as a fluid than a gas. Because of the high temperatures in this state the particles give off ultra-violet and infrared energy instead of visual light. 

The wave patterns made by Jupiter’s charged plasma fields around the poles cause different particle behavior than is caused by earth’s magnetic field. Jupiter’s polar areas draw the charged particles into the polar cap atmosphere, making the aurora more concentrated and less ring-like than earth’s auroras. 

By learning about the activity in Jupiter’s auroras and comparing it to earth’s atmosphere scientists learn about how planets protect themselves from the constant bombardment of space radiation that is deadly to life.

There are many strange phenomena in space that earth does not have, but our planet is made from and exists in relationship with the space around us and the other objects suspended in the heavens. Finding new connections between our planet and another deepens our knowledge about our fragile, tiny home floating in the vast, cold darkness of space.   (back)

October 13, 2025   Hunting Durian Fruit

The durian fruit grows in many parts of south east Asia. It’s related to breadfruit, has spiky thorns all over its shell and can weigh six pounds. There are many species. The edible ones have complex and often strong flavors. They are considered a delicacy in Asia but their aroma is so distinctive and lingering that eating the fruit is banned in public places in several countries.

There are connoisseurs who go to great lengths to find the most perfectly ripe and fresh durian fruit, and the hunt for the perfect fruit must take place in the dark of night.

When durian fruit becomes ripe on the tree it will fall to the ground, but only falls at night. The impact with the ground starts a chemical reaction in the fruit that causes fermentation. At this point the fruit is considered perfect for immediate consumption.

Those who crave the ultimate durian fruit experience schedule travel to the hillside orchards in the rainforests at harvest time. After dark they walk into the forest listening for the sound of durian fruit dropping to the ground. When one is heard they wait to make sure no others fall because being struck by a falling durian causes serious injury. Then they retrieve the fruit, carefully handling it to avoid being cut by the sharp thorns. The taste and aroma of the freshly fallen fruit is worth the trouble of a hunt in the night in a tropical forest.

What does darkness do to the durian trees to make their fruit different than durian fruit harvested in daylight? The durian offers an unusual story of how dark nights affect life. The durian trees’ need for darkness to complete fruit ripening may be a hint of how other plants might also be using darkness in ways we have yet to discover.  (back)

October 6, 2025   Evening Walk at Tunnelville

On October 11th John Heasely and I will lead the annual Fall Astronomy Hike on the Mississippi Valley Conservancy land on Tunnelville Road. If you’re interested, call the MVC to sign up. Or on a clear night take a few friends and some binoculars for a twilight-to-dark walk across this ridge. There is a mowed trail across the middle of the field for easy walking, and the large open area allows a big part of the sky to be seen. If there is no haze the sky will be fairly dark, and more stars will be visible.

The sun sets earlier now so evening walks are easier to do at the end of the day. Younger children can go along and still get to bed on time. Twilight walks in fall and winter are great for them to see birds and animals out at dusk, the full moon rise, and search for the first visible stars. Twilight walks are times for teaching children to be watchful and listen carefully. There’s always something surprising to see in the changing light, maybe a deer or rabbit or owl moving nearby or a sound to guess about, or the last butterflies of the season.

Constellations from the Teapot in the southern sky to Polaris, our North Star in the north are easily visible from the ridgetop trail. The Milky Way galaxy, our home in space, will gradually appear overhead, where more constellations can be found as the sky darkens.

Try a twilight walk this fall to renew your connection to the beauty and wonder of our prairie meadows and dark sky. Give your children evenings to remember and yourself a breath of fresh air at the end of the day.  (back)

September 29, 2025   Butterflies Smell Flowers Too

While cutting brush this week I found many moths tucked into the tall grass. They seemed to be seeking shelter and unwilling to fly. So I started reviewing information on their lives and found more news humans didn’t know about moths and butterflies.

We know insects see light differently than we do. They see ultraviolet light given off by flowers to find the flower’s center. They may also have an ability to smell their food sources. Butterflies and moths use their antenna to detect scents. Those with larger antennae have a narrow range of plants they feed on, and moths and butterflies with small antennae tend to feed on a wider range of plants. 

This also correlates with whether they eat at night or during the day. At night most flowers release little scent, so night feeding moths and butterflies get less scent information from plants and so can’t use a sense of smell to choose where they eat. The size of their antennae are smaller than their day-feeding relatives and they have more generalized diets.

Monarch butterflies are known to prefer certain plants to feed on and to lay eggs on. Prometheus moths that fly at night will visit many types of plants.

Plants and insects influence each other in many ways. Like us, they all have a variety of characteristics and behaviors that help them find food, shelter, travel and get along with all the other creatures around them. They may use scent to find food in some circumstances, and sight in others. Flexibility is common in Nature. 

We’ve learned these fragile, tiny creatures fly over mountains, migrate long distances, orient to the night sky for flight, and use a sense of smell to identify plants. When we learn something about a moth or butterfly the next question could be: What else is there to know about their role in the Web of Life?  (back)

September 22, 2025   Sleeping Spiders

Humans and our fellow species on Earth are more alike than we realize. Sometimes the simplest things show that alongside our differences we share common experiences with vastly different species.

Spiders are one of those species we feel most separate from, yet we share an essential function, that is sleep.

Sleep is recognized in humans by rapid eye movement (REM), changes in breathing, twitching limbs, unresponsiveness to stimulus, and other signs. Spiders do not have eyelids and cannot move any of their eight eyes. But jumping spiders can move their long ocular tubes to shift their retinas, and we can see that occur in the first few days of their lives when their exoskeletons are translucent. At certain times of night, the ocular tubes move around even though the spider seems inert. Spiders also make twitchy, random leg movements during periods of immobility.

Are they sleeping, as we know it? There are around 50,000 species of spiders, so I think there could be many variations of sleep among them, and why wouldn’t they? Just managing eight eyes and eight legs would be tiring.

Spiders follow a circadian rhythm, most are active at night and ‘sleep’ during daylight. Other mammals, octopus, cuttlefish, some fish and reptiles experience REM while resting. Our arbitrary decisions about what other species can and cannot do, and whether they are ‘like us’ or not needs revision. Understanding how we share the world may be the most useful approach to considering other species. Spiders have been on earth for around 350 million years, maybe we can learn from them instead of killing them on sight. Take a slow stroll these cool late summer mornings to see the countless tiny dew-covered webs built by spiders in the dark. While we sleep, they manage insect populations and create something both functional and beautiful. Then while we are awake, they may be dreaming, just like we do. (back)

September 8, 2025   A Problem Overhead

Seeing Sputnik 1 blink across the sky in 1957 excited people all over the world. It was 58 centimeters in diameter and fell back to earth a few months later. Now there are over 13,000 satellites in low earth orbit and over half a million pieces of debris above our heads, some of it the size of a school bus. By 2030 there could be more than 60,000 satellites in orbit and all will leave a trail of trash as they stop working and disintegrate. Every year private companies launch thousands of satellites with no controls on the long term damage they will cause. Already homes, farm fields and other buildings have been struck by our satellite trash.

Because this junk travels at over 17,000 miles per hour, space trash smaller than a penny can ruin a satellite or damage the International Space Station. The Air Force tracks about 25,000 pieces of trash. Sometimes warnings to the ISS or other entities may prevent collisions but this effort is partial at best.

Some governments are considering ways to control the growing problem. Japan has even experimented with a satellite made mostly of wood. Lignosat 1 was made of magnolia wood and assembled without screws or glue using traditional Japanese joinery methods. Launched November 5, 2024 from the ISS, it remained intact for the duration of its orbit. Lignosat 2 is planned for launch in 2026. 

The Japanese experiment is one of several ways being considered to do a better job of preventing space junk and cleaning up after ourselves. We have the technology to both have the benefits of useful satellites and not damage the sky and earth with our creations. Balancing both now will benefit all of us in the future.  (back)

September 1, 2025   Plants See the Light

Plants are aware of and respond to the lengths of day and night. They keep exact track of seasons so they know when to grow, bloom, and make seeds. There are thirteen photoreceptors in plants, five that absorb near-infrared light from the moon and eight that absorb UV light from the sun. Scientists know plants have protein “light switches” that recognize growing darkness and degrade other proteins active during daylight. 

But no one knew how plants turn daylight functions back on. The scientists kept searching and found an enzyme that does the opposite, it stabilizes light sensitive proteins. Plants’ circadian clock proteins provide precise information about when and how fast light and darkness occur. Animal species also have the enzyme that stabilizes photoreceptor proteins in daylight and regulates circadian rhythms. 

The ability to ‘see’ is understood to include recognizing light and darkness. We rate the degree of blindness a human has partly by how well light and dark are distinguished. We think of recognizing light and dark as a function of our eyes but every living entity on earth recognizes light and dark and not all have eyes. Sensing when light and dark change during each 24 hour day regulates biological functions in all of us, human to protozoa. Even temperature or air pressure do not affect every living being as comprehensively as light and darkness. Most can adapt to some degree to temperature and pressure changes without losing normal biological functions but when forced to change fast by artificial light at night all species we have observed have normal functions disrupted. 

While our bodies are repairing cells and resting during the night, plants’ bodies need to do the same things. We all do better when the sun and moon regulate those activities. Maybe keeping Nature’s pattern of day light and night darkness is a good idea. (back)

August 25, 2025   Noctilucent Clouds

Clouds float by over our heads almost daily. We think of them as not too far away and know they are several hundred to tens of thousands of feet above, but yet move in the same atmosphere we breathe and feel at the surface of the Earth.             

Above the clouds the atmosphere fades into outer space, where there are no clouds, right? Not so fast! There are many layers of atmosphere above our breathable atmosphere. The thin band of air we breathe, the troposphere, rises between 7-11 miles above us, less than the distance between Viola and Viroqua. Beyond that are increasingly empty layers of particles still connected to Earth. Somewhere between 30-50 miles above the surface at the edge of the mesosphere, space dust, volcanic dust, water molecules and cold temperatures combine to sometimes create noctilucent clouds. They form at temperatures below -184F in streaks and bands of pale, luminous blue, at between 50-65 degrees latitude. They can only be seen during Astronomical Twilight when both the viewer and the lower atmosphere are in shadow but that high layer of particles is still lit by the Sun. They form only in summer, when vertical winds cause the upper atmosphere to be colder than in winter.

Glowing like no cloud formed closer to earth, noctilucent clouds are one of the most distant formations made in Earth’s atmosphere. Sometimes these clouds form in southern latitudes too but may be much rarer there. Rocket exhaust vapor may cause noctilucent clouds to form. In 2014 a noctilucent cloud formed over Florida after a rocket was launched.

Ephemeral, eerily lit, glowing blue noctilucent clouds in a dark sky sprinkled with stars are as much a thrill to see as the Northern Lights rising high into the night. Look for them as night falls if you are traveling north in the summer. It’s possible you might see them even over the Driftless skies.  (back)

August 18, 2025   Lights Out for Birds

Have you noticed? The birds are leaving again on their long journeys south for the winter. Now we know many millions of birds die each year because they crash into our lit windows as they pass by at night. Seeing the ground below big windows and bright lights littered with dying birds in the morning never needs to happen now that we have simple solutions to stop the carnage.

The International Lights Out Program is beginning to help. From August 15th to November 31st lights are being turned off from 11pm to 6am in cities across the country so the birds can safely fly by. From coast to coast as well as across Canada dozens of cities are beginning to change their night lighting for the birds. Even the Twin Towers Tribute searchlights in New York City are turned off during bird migration hours. Our Driftless hills hosts many birds that use the Mississippi flyway from the arctic to the tropics twice each year. Your home or business can be their last stop or help them on their way. Bright lights from businesses and large buildings are the most dangerous.

I live where it is dark at night, yet migrating birds become caught at our lit windows, fluttering helplessly for hours. You might not notice the birds outside your window, so please join me in remembering to close curtains after dark and turn off outdoor lights during migration hours.

Join the Lights Out for Bird Migration, especially if your business has big, bright, outdoor lights. Go to www.audubon.org to find out how easy it is to allow room for birds to fly by while saving money, and join cities and people all across the US helping the birds fly by. How cool is that? Be part of why where we live becomes known for making both birds and people happy.  (back)

August 11, 2025   Daytime Stargazing 

Remember when your parents told you to ‘never look directly at the Sun’? And how we sneaked peaks anyway, because kids are curious. And how that peak told us in no uncertain terms not to do that again? Well, whether you are a child or a grown-up this month we have the rare opportunity to gaze at the surface of the Sun and not go blind. 

For 39 years the Northwest Suburban Astronomers from Chicago have come to Wildcat Mountain State Park for a week in August to look at the night sky with their telescopes. From small but powerful telescopes the size of a loaf of bread to tall tubes of mirrors that need a ladder to reach the eyepiece, they set up telescopes all around the meadow. On August 17th between 1 and 4pm telescopes with special filters will be set up for looking at the Sun so you can stargaze with the astronomers during the day.

The Sun is our own special star, the closest star by far to Earth. The Sun’s surface is complex and changes rapidly. We are familiar with solar flares and sunspots but there are many other features on the complex surface. As the intense activity in the interior of the Sun moves materials and energy toward the surface bumps, bubbles, swirls, dark spots, plumes and flares constantly change the surface we can see.

For a special summer outing take your family to see the friendly astronomers and impressive telescopes, and a rare chance to see our own star up close. I’ll be there, and hope you can join me. 

Take advantage of another unique sky viewing opportunity on August 16th when the telescopes will be available to the public for night time stargazing. Make a weekend of stargazing for family and friends, you’ll be amazed.  (back)

August 4, 2025  August Starry Sky

August is the height of summer, gardens are overflowing, days are hot and the nights are filled with stars. Clear winter night stars sparkle in the cold air and seem closer and brighter. But August nights offer many star gazing pleasures. From beautiful sunsets and sunrises to constellations to planets moving into view to the best meteor shower of the year, these nights are spectacular. Stargazers in the northern hemisphere make sure to be out after dark in August.

Begin with watching the full Sturgeon Moon rise on the 9th. There is a beautiful lineup of four visible planets, Mercury, Venus, Jupiter and Saturn, on the 11th  in the early morning sky. Get up early, make some tea and enjoy the light show.

The Perseid Meteor shower peaks on the 11th and 12th. This year it coincides with the full moon most of the night. Some people think the full moon interferes with seeing the most ‘falling stars’ but I think it simply makes a different light show. You’ll still see meteors, as well as get to look at the beautiful moon! The Perseid Meteor shower can be seen for several days before and after this date.

For the next week the moon and planets will move around each other in a complex dance making beautiful patterns in the sky as the moon wanes to a fainter crescent.

Summer constellations to look for are Sagittarius in the center of our galaxy, the Big Dipper and Little Dipper and nearly overhead, between the Big Dipper and Sagittarius is Lyra. Then look for the three stars Vega, Deneb and Altair that make the Summer Triangle. Vega, one of the brightest stars in the sky is in Lyra. A star chart and a lawn chair are your tickets to exploring at least a small part of the universe. (back)

July 28, 2025   Light and Chicken Development

There are over 34 billion domestic chickens in the world, and over 9 billion in the US. Most are raised under artificial lights set to unnatural time intervals to maximize growth. Information on how that affects them is of great interest to those raising the chickens. Today a broiler chicken’s life ends as someone’s dinner at 40 days because of manipulation of feed, medications, and the amount of light in the chicken barn.

We know light and dark cycles regulate biological rhythms and functions and each year we learn more ways light affects more aspects of life. While  chicken growers are increasing speed of growth by manipulating light other unnoticed changes are also happening.

 Researchers in Sweden and Brazil exposed chickens to artificial light schedules early in life, then examined RNA and DNA gene activity in the pineal gland in the brain for changes from a normal baseline. The epigenome, that turns DNA on and off, was most affected. The scientists admitted surprise to find the “difference between males and females in the pineal gland almost disappeared under chronic light stress” and the female chickens became more male-like even though their DNA did not change. The DNA was turned off, not changed. Though both male and female birds were affected, Dr. Carlos Guerrero-Bosagna said, “This suggests female birds are particularly vulnerable to environmental stress…These findings raise questions…about how artificial lighting may affect biological rhythms in other species, including humans”. 

It's interesting their conclusion noted the question of human response to artificial light. I take the hint. While waiting for those with the knowledge to find more answers about the effects of light on our lives, I’m keeping as much natural dark night sky around our home as possible. (back)

July 21, 2025   The Summer Triangle

This week we’ll tour the Summer Triangle, which is an ‘asterism’, a pattern of stars that are recognized but not defined quite the same as a constellation. Three of the brightest stars in the sky, Deneb, Altair and Vega make the Summer Triangle, also known as the ‘Navigator’s Triangle’ because it can be seen everywhere in the northern hemisphere and from most places in the southern hemisphere. Used for centuries for navigation by sailors as well as land travelers, this star pattern was described by the Chinese at least 2,600 years ago as well as mentioned as part of Japanese and Korean stories and festivals.

Altair, in the constellation Aquilla, is located on the celestial equator. Vega is the fifth brightest star in the sky and was our northern pole star about 14,000 years ago. Vega will again be the ‘north star’ in 13,727 years. Deneb is a blue supergiant star. Even though it is between 1400 and 2600 light years away it is one of the brightest stars in our sky. In 9800AD Deneb will be almost aligned to be our pole star. Stars take turns being our ‘north star’ depending on which direction the earth tilts.

These three stars are easy to find in the summer sky and each can be used to find other astronomical objects and orient to directions. On summer nights the Summer Triangle is nearly overhead and rises in the east at sunset and sets in the west at sunrise.

Each star’s name relates to birds. Vega is Arabic for ‘falling eagle’. Altair means ‘flying eagle’ and Deneb means ‘the tail of the hen’. We locate Deneb in the tail of Cygnus, the swan. 

Explore orienting yourself to the sky and the land around you by finding this reliable, ancient map of stars. (back)

July 14, 2025   What About Those Bulbs?

We’ve toured cities, businesses, parks and other places that have made lighting changes to increased safety and reduce pollution and costs. We’ve considered what are desirable criteria for choosing a light. Now, what exactly are smart, efficient light bulbs and where do we find them?

The light that does minimal interference to normal dark night sky has a Kelvin (K) rating of under 2700K. The Kelvin number is on every light bulb package. Ignore the ‘warm’, ‘cool’, ‘daylight’, or other descriptions as there is no standard they agree on.  Low Kelvin numbers mean warm color-temperature light that does not scatter as much into the atmosphere. It does not relate to the amount of light given off by the bulb. A warm color- temperature bulb gives the same amount of light as any other bulb of the same lumens. 

Light rated above 2700K becomes more like daylight the higher the number, in that it scatters much more into the atmosphere. This is wasted light that you pay for. One little doorway light changed will affect the life around you as well as your light bill over time, but if you have floodlights or multiple lights the difference to everyone nearby and your wallet will be noticed very quickly.

Go to the Selecting Bulbs page at  https://www.4darkskies.org/home/resources/selecting-bulbs for places to find bulbs. Also ask your local hardware or big box store to stock these lighting options. When they get requests they offer the product but some stores are not aware yet of the recent improvements in light bulb options. 

If you are involved in decision making about any outdoor lighting, before replacing fixtures and bulbs that are wearing out become informed about what’s new in lighting that has benefits we didn’t think of in the past. Good lighting and better savings are now easy choices. (back)

July 7, 2025   Good Lights Bad Lights

There’s more news lately about light pollution and the loss of starry skies. But artificial light has changed life for the better in so many ways. Is artificial light bad, or good?

As with many things, jumping to a foregone conclusion is not helpful and so it is with understanding artificial light. There is no denying that being able to see at night is very important for many reasons. We are safer and can do many things with adequate artificial light. Rather than considering light as ‘good’ or ‘bad’, let’s look at whether it is useful or wasteful, cost effective or expensive, polluting or conserving our resources.

The problems with artificial light have to do with how much is wasted by dispersing into the atmosphere and the sky, the damage that causes to all forms of life, the wasted energy given off as heat and the 3 billion dollars or more each year that is spent on that waste in the US alone. An incandescent bulb is 90% and an LED bulb is 30% waste heat. How much of that is part of your electric bill?

We now have some good examples in our communities of lighting that does not produce waste and pollution. Light bulbs and fixtures are available at the same or even less cost than those commonly used. There is technical and hands-on help for making smart lighting changes. There are large cities that have successfully changed to smarter lighting and saved a lot of money in doing so. Tucson, Arizona is a good example with about a million people benefiting from dark sky lighting. Changes are being made all over the world to have effective, safe, affordable lighting. Check out the possibilities. Visit these websites: www.4darkskies.org  (this is the Kickapoo Valley Dark Sky Initiative website) www.darksky.org  www.starryskiesnorth.org. Light up your life with smart, healthy, cost effective light. (back)

June 30, 2025   Lights to Live By

Last week I talked about how to consider the quality of lighting. Now let’s tour some examples to experience how we can have it all; a healthy, functioning world and the light we need to see well at night.

We can go to Europe where many places have made advanced changes in lighting. Or we can go to some National Parks, or urban locations in Illinois, Ohio, Oregon, Wyoming, Missouri, and other places. Arizona has numerous areas that control light pollution. Flagstaff, a city of over 75,000 residents is the first Dark Sky city in the US. Tucson, Arizona has a metropolitan area population of over one million people benefitting from dark sky ordnances, and the surrounding Pima County also has dark sky ordnances for many years. If you are traveling, watch for places that have made those changes. 

Now we can experience these smarter lighting choices close to home. Several communities, parks and businesses have made the change to save money and be good neighbors too. Take a drive in the evening and check out these recently upgraded lights.

Visit the La Farge Village Park and Emergency Services building, the sample lights on Rock Avenue in Viroqua, the Ontario Village Hall and Fire Station, the Kickapoo Valley Reserve Visitor Center, and Wildcat Mountain State Park. Everything that needs light is well illuminated in these places but there is little glare and little wasted light going out into the sky.

As with all technology, artificial lighting is changing. We did not know decades ago the problems artificial light caused. As we learn, we are developing better options to have the light we need without the inadvertent problems it can cause.

Become familiar with the new technology. Then join those who are already benefitting from the improved choices in lighting and start saving. (back)

June 23, 2025   The Green Flash

There is a special event that happens at sunset called a Green Flash or a Green Rim. As the last edge of the sun disappears below the horizon, sometimes a green flash of light shoots up from the edge of the sun, or the rim of the sun is green. Caused by Earth’s atmosphere acting as a prism, light near the horizon is separated into the color spectrum. The lower edge of the sun is more red and the upper edge is always green. The sun is below the horizon so we never see the lower, red edge at that moment.

Seen most easily in dry, still air, Green Flashes can be spectacular or faint and take both luck and planning to see. 

Early this spring I stood on the edge of the Mt. Lemmon summit near Tucson, Arizona just before sunset. Guided by University of Arizona astronomers, we carefully watched the top edge of the sun at the horizon, and then we saw it. A  neon green band of light arced around the sun’s edge and two bright green flares of light shot upward. For two seconds we saw what the astronomers called ‘the most spectacular’ green flare they had ever seen. It was beautiful!

I have seen faint Green Flares in Wisconsin. Maybe you can too. Here’s how to look for them. Of course, never look directly at the sun. Permanent damage to your eyes is almost guaranteed. It is safe to look after the sun has gone below the horizon and only the tiniest rim of light is left. That is the only time a Green Flare can occur, so there is no advantage to looking at the sun before that. On a clear, calm evening look just to the side of the sun as it disappears. Like rainbows and Northern Lights, most of the time they are not there but when they are it is worth the many times you’ve tried to see them. (back)

June 16, 2025   Fireflies    

Once a year the stars seem to fall from the sky into the meadows and pastures all around us. If you walk out to open grassy fields at sunset in June you may walk through fields of floating stars.

Rising from the grass in vast numbers as the real stars pull the curtain of night over our heads, countless adult Lampyridae beetles embroider designs on the darkness in a dizzying display of swirls and dashes of yellow or green light.

Their aerial light show is the last part of a life lived underground for a year or two  as one inch long larvae. After munching on slugs and worms, the larvae change into adult form with wings and for a few warm evenings in early summer become one of Nature’s most loved spectacles.

There are fireflies on every continent but Antarctica, and there are at least 2,200 species in the world. As well as making light, they have complex lives.

Fireflies need strong defenses to balance their visibility. One strategy they have is to expel drops of blood to repel predators. Bats are observed to avoid them.

Unlike our artificial lightbulbs that give off 10% light and 90% heat, fireflies have a ‘cold’ light, there is no heat involved. Two chemicals in their bodies interact to make their light. They can adjust the light by how much oxygen they allow to mix with the two chemicals.

In Japan long ago, women pinned fireflies in their elaborate hairdos for evening walk through lamplit towns and parks.

Fireflies have been lighting summer evenings for over 100 million years but are now disappearing all over the world. They are still here in our meadows so take a walk after dark in a grassy field near you and enjoy their special summer night light show. (back)

June 9, 2025   Hatching Baby Birds

It sure looks simple to us, how birds just sit on their eggs for a few days and then the baby birds hatch themselves. But as we found out about mosquitos, there is more going on than we notice.

Birds work hard to incubate their young. During the day they must feed themselves and keep the eggs consistently warm and safe from predators. 

Because chicks develop externally from the mother bird in the egg they are vulnerable to environmental conditions, especially temperature changes, so those parent birds work hard to care for them each day. During the night birds catch up on their rest while sleeping on their eggs, keeping egg temperature stable. 

Research in England found that night-time incubation restlessness strongly reduced hatching success because egg temperature varied. There can be numerous reasons a bird feels restless at night but artificial light was found to be a significant factor disturbing the birds. The more egg temperature varied at night, the lower the hatching success.

The study did not look at adult bird health in relation to exposure to artificial light at night. But if anyone works hard all day and does not sleep well at night there are eventually unavoidable bad effects on health. When you are tossing and turning after a long day and know you’ll be tired in the morning because you didn’t get enough sleep, you may be sharing a restless night with the little song bird out in your yard or in the nearby park who is also struggling just like you, to get a good night’s sleep.

Birds are disappearing all over the world so if we can improve any one of the problems they have it could help them deal with other stresses. Artificial light at night is the easy one to fix.

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June 2, 2025   Mosquitoes

Well, they’re back. A couple ankle bites while sitting on the porch in the evening gives notice the insect we universally dislike is here for the summer. But wait, is our discomfort the whole story? As usual, there is more going on in Nature than we realize. Mosquitoes deserve a closer look.

Mosquitoes were feasting on dinosaur blood long ago. Now they visit us because often there are not many other options. They will feast on amphibians, earthworms, armadillos, and even some kinds of fish as well as mammals. We may not even be their favorite meal, if they have another choice.  All mosquitoes need nectar and pollen for food. Many but not all need one blood meal for reproduction but only a hundred or so of the thousands of species carry diseases to humans.  Some species’ larvae eat the larvae of other mosquitoes. Humans use these species in rice fields and other areas to eat larvae of disease-carrying mosquitoes.

Many mosquitoes are brightly colored or striped, or have elaborate feathery legs and some are very large. The ‘elephant mosquito’ eats only nectar and is almost an inch long with long, long legs that drift below them as they fly.

We are learning they are significant pollinators. Feeding on flowers at night, their work is unnoticed by us. Because of their large numbers they do a lot of the essential pollen transportation the flowers need.

Changing outdoor lights to a warmer color temperature that does not attract insects and using a small fan in your outdoor seating area can reduce mosquitoes’ attention on you.

So swat away if one is biting you, but skip the bug zappers that kill all the bugs the plants depend on, and take a closer look around plants at twilight, you might see those unexpected flower-tenders at work.

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May 26, 2025   Flying With Moths

There are many fantasy stories of humans flying on the backs of birds and even butterflies. Let’s go flying with moths for a different view of the world.

We’ve all seen moths endlessly fluttering around lights at night. We don’t realize most of them die there, unable to escape. What’s going on?

As humans become aware of the value of moths we have learned more about why moths and other insects are attracted to outdoor lights. 

Moths us low levels of light from the night sky to stabilize their flight. ‘Dorsal light response’ causes moths to keep their back facing the brightest object they can see to orient for normal flight at night. For millions of years this has been the night sky.

Excessively bright artificial lights interfere with moths seeing the sky, so they orient their backs to our outdoor lights and cannot fly away. They fly up until they stall and fall, or fly inverted until they crash and die, trying to keep their backs to the light. What looks to us like harmless fluttering is really the moths struggling to escape the light.

Many moths migrate, often across continents, mountain ranges and oceans. Some fly one to two miles high. Hummingbird hawk moth, Painted Lady, and many others share the Monarch butterfly’s long journey across the continent. When you first notice a familiar moth it may be because they have just arrived from a long journey. Migrating at night, moths and other insects have the same problems with artificial lights that migrating birds have.

Turn off outdoor lights when not using them and shield them to prevent light from leaking upward. Let the moths fly free to pollinate the plants we love and need. The cost is small, the effort takes only a few minutes, but the benefits for not only moths but humans is incalculable.

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May 19, 2025   More About Moths

Any one animal, plant, or element of the living world, when closely observed, is intricate, beautiful, unique, does something surprising, and always does something useful. 

Moths are one of those seemingly unremarkable creatures we ignore or kill without thinking. Let’s take a closer look at a very important part of warm weather nights.

Moths and butterflies share the order Lepidoptera. There are over 160,000 species of moths, ten times the number of butterfly species. We can tell whether the winged beauty we are looking at is moth or butterfly by the antenna. Butterflies have thin antenna with a ball at the end, moths have feathery antenna-most of the time. In Nature there are many variations so sometimes you may see a moth with thin antenna.

Moth caterpillars are often more colorful than the adult moth. The large, bright green poplar hawk moth caterpillar has white stripes and dots and a long white ‘horn’ but the moth is shades of gray and brown, blending in well with tree bark. The familiar ‘woolly bear’ caterpillar has orange and black bands, but turns into an Isabella Tiger moth with pale yellow-brown or reddish-brown colors. Cecropia moths are beautiful, but when in caterpillar form are positively festive, with bright green bodies with red and yellow-tipped protrusions and black spines.

Moths developed around 190 million years ago, long before butterflies showed up. The few moths that eat human crops that have replaced their natural foods are far outnumbered by countless moths that plants depend on for reproduction. The cycle of life between caterpillar eating leaves, moth pollinating the plant, and the plant reproducing has worked well for for millions of years. This summer take a closer look at the moths flying silently from flower to flower through the night.

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May 12, 2025   Moths

When we see butterflies and bees at spring flowers it is also time for moths to be active. Moths are as varied and beautiful as butterflies. They are a major source of food for bats, small mammals, and birds, and are at least as important as bees and butterflies for pollination. Did you know there are more than ten times as many moth species as butterflies?

Moth caterpillars can be very beautiful. Look up pictures of Tussock, Io, and Imperial moth caterpillars, a few of the most striking species. The familiar and common ‘woolly bear’ caterpillar turns into an Isabella Tiger Moth.

Moths are complex as well as beautiful. Some moths make ultrasonic clicks to confuse bat echolocation. The beautiful Luna moth, as well as the Promethea, Polyphemus, Cecropia and others do not eat as adults and have no mouth. They store enough energy from eating while in caterpillar form to live a short time in moth form.

Some moth caterpillars’ hearts stop beating and their chemistry changes in cold weather to survive winter. Many moths also migrate, sometimes thousands of miles. 

Let the moths fly in the dark where they belong, not around your outdoor lights, where many of them die without reproducing or pollinating. 

Now that we know moths are essential for pollination of many plants we can give them room to live by choosing smart lighting for our night time visibility needs so moths are not trapped by light pollution. 

As the moths still surviving arrive with spring, help them by encouraging native plants they need for food and shelter. When one rests on your window, use a hand lens to see their unique colors and shapes. Add moths to the joys of summer nights. We need all the parts of the Web of Life.

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May 5, 2025   Evening Walks

When a doorway to a new experience is found, unexpected pleasures often come into our lives. Sunsets are our doorway to the beauty of the night. They are an invitation to walk through twilight into our beautiful hills and fields so that the end of your day gives you what the birds and animals get for free- beauty, pleasure, and rest.

If you are unfamiliar and unsure about being under the stars, in the darkening fields as the last colors fade from the sky, the sunset is a wide-open opportunity to add the always free, always available, always beautiful evening to your life. Before darkness comes, the twilight gives us light to see as we walk, and to feel connected to the fading daylight.

Especially in times of stress, when we are tired or worried, a free, easy to access pleasure is valuable. The busy business of the day retreats with the approach of night. Quiet, slowed movements fit the  fading light. Nature offers us relaxation and rest.

Let the sunset draw you out as the eastern sky turns indigo, the western sky displays pinks, oranges and gold, and birds make last flights in the dusk. A cloudy evening makes soft grays, pinks and blues, no less beautiful than the bright sunsets.

Most life is oriented to transition between activity and rest by the sunrise, sunset, and twilight times. We can use those times of day to slow down, relax, and receive the free gifts from the land and skies we are so fortunate to live within.

Walk out into the open at sunset. If you can’t do that, simply stand outside your door and watch the light change and the first stars come out. Fill the end of your day with rest and beauty. You’ll sleep better too.

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April 28, 2025   The Oldest Astronaut

On Sunday, April 20th, Don Pettit returned to earth after seven months in space on the International Space Station. He turned 70 years old as he hurtled toward earth in a tiny metal capsule, slowed by an enormous red-striped parachute that glowed in the rising sun.

Accompanied by two Russian astronauts, flying on a Soyuz landing craft, the three landed in Kazakhstan. Their fall to earth took about three hours, less time than it takes to fly to Los Angeles.

While on the ISS the astronauts shared research on plant growth, fire behavior in microgravity, and water sanitization. They lived together in tiny spaces under extreme conditions and got along, got their work done, and learned things that benefit the rest of humanity.

It’s interesting to consider the effort it takes to make a successful ISS mission. From ideas sketched on paper napkins to launch, experts from fifteen countries work together on everything from navigation to fuel technology, health, radiation effects, clothing, air supply, waste management, communications, supply chains, and hundreds more design, development, deployment, maintenance, and monitoring jobs. Each person must cooperate perfectly so that each bolt, instrument, communication, calculation and action is exactly right for the whole mission. It’s hard to imagine how that can work, but it does. NASA’s policy of international collaboration has been working successfully for decades.

During a 29 year career Pettit has spent more than 18 months in orbit, his life depending upon the cooperation of people from fifteen countries. Achieving a great goal shared by people from so many countries makes everyone involved feel great. Astronaut Pettit’s circle of friends is as big as the world, as big as his orbits around earth, grown over a lifetime of sharing knowledge and skills with people from all around the world.  (back)

April 21, 2025   Big City Lights

Tucson, Arizona has become one of my favorite places, partly because it has a long commitment to best lighting practices. With just over a million people, this city has shielded, low temperature street lights because of several astronomical observatories nearby. The city changed and shielded almost 20,000 street lights and now saves 2.16 million dollars a year on lighting. The 3,000K LED bulbs will last 25 years instead of 8 years for the old bulbs. Residents and businesses had little problem adjusting to the lighting changes and I and my husband and friends have enjoyed the way the city looks and the quiet feel of streets at night.

Wildlife and the surrounding environment are also big winners. While people look up from their backyards or streets and see stars the birds, insects, animals and the fragile but vital ecosystem has the dark nights needed to live and function normally.

There is no problem seeing where you are going there, whether walking or driving. The national, state and city parks in and around Tucson are minimally disturbed by light pollution. The city of Tucson knows outdoor light can be functional and also do little harm, and they are happy saving money too.

A bright, unshielded outdoor light causes glare that travels far across the land. Unshielded light shining in your neighbor’s eyes and even into their homes prevents them from controlling light on their property. Smart lighting is an excellent way to be a good neighbor. This is one problem that we can easily fix, and in doing so many other problems are improved. Shield that bulb to send light where it is useful and not upward, put in a 2200K LED bulb, then watch your savings add up. A million people in Tucson know it works. (back)

April 13, 2025   Star Tender 

There are stories of special people who take children on nighttime travels to the stars but I met a real Star Tender on the sidewalk in downtown Tucson, Arizona. Tall and silver-haired, Star Tender presides over the telescopes at the Sky Bar on 4th Avenue on Saturday nights.

Cars and streetcars rumble past while Star Tender opens a window to the heavens for anyone strolling by who wants to meet the stars. A group of young students, tourists with drinks in their hands, and couples walking by line up to take a peak through the telescopes. As each one looks there is a long silence. “Wow!” is the first involuntary word heard. Then the questions start. Some people want to know how the telescopes work, some wonder about distances or sizes or what a star is made of. Star Tender has the answers, for he’s been keeping company with the night sky for many years.

Star Tender tells stories of Jupiter’s bands of color, Saturn’s rings, craters on the Moon, and how the telescopes work. He has boxes of mysterious parts for the telescopes, computer screens showing pictures he’s taken of stars and planets, and stories about dark desert nights exploring the sky. 

Star Tender moves his telescopes back and forth, catching the beauty and mystery of our night sky for unsuspecting passersby.

And so on a busy downtown street in a big city the stars are brought to earth, giving people who take the time to look a little bit of the wonder that starry night skies have always brought to humans. 

Late in the night as the Sky Bar darkens and the streets empty, Star Tender carries his telescopes far into the dark desert hills to watch the stars in solitude but next Saturday he will return to bring the moon and stars back to 4th Avenue. (back)

April 6, 2025   The Schulman Telescope

After the tour of the Mt. Lemmon Observatory facility last week I also joined a group for star gazing after dark with the 32” Schulman Telescope. It was very cold up there! The dome the telescope lives in was opened to the sky, the ground was covered in snow and we were over 9,000’ in elevation.

The first star we looked at was the sun. Two telescopes with different filters showed flares, sunspots, and the pebbly surface of the sun. Then we stood at the western edge of the mountain to look for ‘green flash’, an uncommon optical effect seen at sunset or sunrise. That evening the sun gave us a perfect arc of bright green light with green rays on both sides of the sun just as it disappeared below the far mountains. 

Each telescope lives in a silo that looks similar to our grain silos. The roof slides open for viewing the sky. We looked at stars, planets and nebulae while hearing stories about using these big telescopes, information about the objects we were looking at and a few good jokes too.

Most of the group had not looked through a telescope before. The exclamations of “Wow!”  and a stream of questions came with every new object observed. Finally the telescope focused on the Orion Nebula. The mysterious world of bright glowing gas clouds filled with clusters of brilliant stars and layers of shadows was suddenly real to the viewers. 

Later, on the way down the mountain, many of the cars were stopped at lookout points, the people standing out under the clear night sky, looking one more time at the stars.

If you can still see a normal night sky with bright sparkling stars take time to go outside, look up, and enjoy the always amazing gift of a starry night.  (back)

March 31, 2025   Exploring Mt. Lemmon Observatory

A special opportunity was offered to me last week, a private tour of the Mt. Lemmon Observatory on the mountain above Tucson, Arizona. A long drive up the famously scenic road to 9,157 feet elevation took me from warm desert to snow and cold. 

At a locked gate I jumped into Joe Hoscheidt’s truck for the mile and half drive to the summit. Unlike the highway, there was no guardrail between the edge of this road and the thousands of feet of steep slope to the desert below. 

Joe is the Operations Supervisor for everything “from toilets to telescopes” at the Observatory. He and his crew take care of plumbing leaks and electrical problems, fix the telescopes and keep them running, maintain the buildings, the power plant, and telescope silos as well as keep the roads open year round.

I thought he would have a lot of engineering training but he’s a biologist “with a great crew”. Each staff person has multiple skills, sharing work when needed and each one loves their job. 

The power for the eleven telescopes is generated by huge old diesel turbines. There is a large machine shop, a room with computers from back in the day when astronomers actually looked through an eyepiece directly at the sky, as well as control rooms where telescope functions, scientist schedules, and maintenance schedules are managed.

Later in the evening guides opened the 32” Schulman telescope for a few hours of star gazing through the world’s largest telescope dedicated to astrophotography. Learning about what goes on behind the scenes to keep the telescopes working was an unforgettable experience and made me appreciate the privilege of being able to use this telescope. I’ll have more stories soon about what we saw that night. (back)

March 24, 2025   Mirror Lab Tour

This week we’re going on a tour of the University of Arizona’s Richard F. Caris Mirror Lab, where the largest telescope mirrors in the world are made. Hidden underneath the university stadium, the only location with enough electrical power for the kilns that form the mirrors, this lab works in collaboration with many other universities and seven countries.

Spin casting and a honeycomb form of mirror were developed here, making it possible to create much larger mirrors than with traditional casting methods. The mirrors are made of borosilicate glass which resists heat expansion. This lab can make mirrors up to 28 feet in diameter. Even with a honeycomb construction, a mirror this size weighs between 25 and 30 tons, but is 85 percent lighter than traditionally cast mirrors of similar size would be.

Each mirror takes four and a half to five years to make. Once a mirror is cast the glass is cooled for three months before more work can be done on it. At least thirty-five people work on the process of making a mirror in the lab.

The cooled mirror is polished by hand with very fine abrasives until it is smooth to one millionth of an inch. If a mirror were the size of the US, the largest irregularity in it would be one inch high. When finished the mirrors are encased in a special container, bolted to the inside structure of a ship and sailed to their destination.

The Mirror Lab has been making mirrors for the Giant Magellan Telescope since 2005, and will have the last mirror made by 2030. The telescope is being built on a mountain in Chile. The data from this telescope will be open sourced so anyone in the world can learn from and use the information it gathers. Go to giantmagellan.org to explore more of the story.  (back)