September 12, 2024

(Q&A) Dennis Mammana: Astronomy and Dark Skies

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Dennis Mammana Interview

Dennis Mammana: A Celestial Bridge to Borrego Springs’ Dark Sky Legacy

Meet Dennis Mammana, a passionate astronomer with nearly five decades of experience in unraveling the mysteries of the cosmos. Dennis’s journey began in Easton, PA, where he was captivated by the launch of the first Earth-orbiting satellites in the late 1950s.

With a degree in physics and astronomy from Otterbein College, he pursued further studies at Vanderbilt University, where his research involved a year-long study of distant Seyfert galaxies. This journey culminated in a coveted one-year internship at the renowned Strasenburgh Planetarium.

Dennis’s career has taken him to prestigious institutions, including the Smithsonian Institution’s National Air & Space Museum , the University of Arizona, and the Reuben H. Fleet Space Theatre & Science Center in San Diego.

 

Beyond academia, Dennis is an accomplished night sky photographer, earning an invited membership in TWAN (The World at Night). His celestial images have graced international publications and NASA’s Astronomy Picture of the Day.

 

As a versatile public speaker, Dennis has captivated and enlightened audiences spanning the globe, from local gatherings to international venues, encompassing diverse age groups and backgrounds, and catering to both novice enthusiasts and seasoned experts. His expertise extends beyond conventional boundaries, as he has orchestrated numerous public observing and sky photo expeditions worldwide. 

For over 32 years,  STARGAZERS , Dennis Mammana’s beloved column, has been a window to the cosmos. 

Borrego Springs International Dark Sky Community 

Notably, Dennis has a deep connection to Borrego Springs, the only International Dark Sky Community in California. In 2009, he was honored as the Grand Marshal of the 44th Annual Borrego Days Desert Festival for his contributions to preserving its dark skies.

Q&A Interview with Dennis Mammana

1. What Inspired Your Astronomy Career? 

Dennis : I began looking at the stars when I was just 7 or 8 years old. My father and I spent time outdoors watching for the first satellites that were launched from Earth, and I fell in love with the stars. Not long after that I got a small telescope and began peering deeper into the sky. And, when my eighth-grade teacher presented a unit on astronomy, I was hooked, and I knew that’s what I wanted to do with my life!


2. In what ways has technology enhanced the stargazing experience for enthusiasts and the general public? 

Dennis : Over the past few decades, technology has trickled down from professional astronomy to amateur astronomers. Today, computerized telescopes, electronic imaging, remote observing, and more are being used nightly by thousands around the world. They are using small backyard telescopes to take photos that rival those of the largest observatories just a few years ago, and are doing valuable research on many cutting-edge topics in astronomy.


 3. What technology trends do you foresee for the future?

Dennis : If I were Isaac Asimov I might have a good answer for you… alas, I can only begin to imagine how technology will change astronomy in the future! 

One way it might change for amateur astronomers is the use of adaptive optics in which the turbulence of our atmosphere is reduced to make our images sharper.  I also suspect much more of astronomy will become robotic which, in a sense, is a shame since part of the magic of studying the universe is being outside under the stars. 


 4. Are you particularly excited about any specific stargazing or astronomical technologies, discoveries, events, or missions? 

Dennis : To me, the search for planets orbiting other stars is particularly exciting. As of today, we know of more than 5,500 planets in orbit around other stars, and astronomers are now using technology to study the atmospheres of those planets for signs of life.  I was fortunate to co-author  the first book on the search for these worlds , so I may be a bit biased! 

And, of course, large ground-based and spaceborne telescopes are growing at an unprecedented rate. The Hubble Telescope (which has been revolutionizing our concept of the universe since 1990) coupled with the recent launch of the James Webb Space Telescope and the upcoming 30- and 39-meter telescopes are ushering in a truly golden age of astronomy.


5. Are there any television shows, documentaries, or movies that you suggest to people who want to learn about Astronomy? 

Dennis : Of course, there are the standard Nova programs about space and astronomy—those are always excellent. And any books by Carl Sagan are at the top of my list!

As for movies, perhaps my favorite is the 1997 film “Contact” (story by Carl Sagan) in which Jodie Foster plays a radio astronomer in search of signals of extraterrestrial intelligent life, while Matthew McConaughey plays a Christian philosopher who, as her love interest, creates quite an intellectual struggle for her. While the plot is interesting, it’s the subtext (the constant conflict between science and belief) that captivates me.


6. What tools do you suggest for a beginner if they want to start learning more about astronomy?

 

Dennis : My first recommendation is to get out under the stars to begin learning constellations, the movements of the moon and planets, and how the sky changes during the weeks and months. There are plenty of apps to help, though I find them only marginally useful since information appears quite tiny on a smartphone.

I also recommend keeping up with my syndicated column “
Stargazers ”; if it doesn’t appear in the local newspaper, one can subscribe to it free via email. The “subscribe” button is tiny, and located at the bottom of each column near my photo. 

Another way to learn is to visit your local planetarium, as well as become involved with your 
local amateur astronomy club ; many communities have one!

 


7. What steps should Borrego Springs take to continue highlighting its dark sky designation? Is there another city that we should look to as an example? 

Dennis : I think that, for as small as it is, Borrego Springs is doing great in highlighting our International Dark Sky designation—it’s quite a selling point. As one who regularly sees people visiting here from around the world and participating in my  Borrego Night Sky Tours , I’m very happy about how many people have learned about us from the Chamber of Commerce, the State Park, ABDNHA and elsewhere.


8. What are your visions for the future of Borrego Springs as an International Dark Sky Community? 

Dennis : I hope we can continue to enjoy a dark sky in the face of increasing light pollution from cities around us. We must make sure that lighting in our town is aimed downward and shielded, and that any new buildings follow or exceed the strict ordinances put forth by San Diego County.  Our dark sky is one of the reasons that many enjoy our desert town, and why many choose to live here. DarkSky (formerly the International Dark Sky Association)  shares with the public many ways  we can help preserve our dark sky while, at the same time, having all the outdoor light we need and saving money on electricity. 


 9. What is the best time to visit Borrego Springs to get the best view of the sky?

Dennis : There really is no “best time”. The sky during every season is always exciting, but the weather can be good or bad, just like anywhere else. In the summer months (for example July and August) we have the best view of the Milky Way, while in the winter months (January and February) we see some of the most brilliant stars of the entire year.

On average, Borrego does tend to see more clouds (and occasionally some rain) during the late summer and winter months, but this can be quite variable from year to year, and there is often no way to predict sky conditions any particular night until that night.


In Appreciation: Dennis Mammana’s Enduring Impact

Dennis now pursues his passion as an astronomy writer, lecturer, and photographer beneath the pristine, star-studded skies of Southern California’s Anza-Borrego Desert, where he also conducts captivating night sky tours in Borrego Springs and Anza Borrego State Park.

We extend our sincere appreciation to Dennis Mammana for his time and dedication. His contributions to Borrego Springs’ Dark Sky Community and the field of astronomy are invaluable.

As we continue to explore the cosmos and protect our natural wonders, let’s remember the guiding light that Dennis Mammana has been for our community and stargazers worldwide.

Learn More About The Night Sky

March 6, 2026
By Dennis Mammana Week of March 8-14, 2026 If you hear the word "superstar," what immediately comes to mind? Perhaps names like Tom Hanks, Taylor Swift or LeBron James? That's certainly understandable; they are all undisputed superstars who attract the attention of paparazzi and fans alike. If you're an astronomer, however, you may answer this question differently. For example, when I hear the word "superstar," I think of UY Scuti, WOH G64 or RSGC1-F01. Yes, these are superstars, but not quite how people may think. These are some of the largest stars known in our galaxy and, for that reason, are quite intriguing to us celestial paparazzi. Regular readers of this column know that our sun is also a star. It appears big and bright in our daytime sky because not only is it rather close (about 93 million miles away), it's also pretty large (nearly a million miles across). It sounds huge, but our star is rather small on a cosmic scale, and believe it or not, there are stars out there that would dwarf our sun and make it look tiny. These are the true superstars! Until recently, the largest star known was given the hopelessly poetic name of UY Scuti. At a distance of some 9,500 lightyears from Earth, UY Scuti is what is known as a red hypergiant star, with a diameter some 1,700 times that of the sun! All that changed recently, however, when astronomers found a gargantuan star some 2,150 times larger than our sun! It's named Stephenson 2-18, and if you'd like to get a peek at this stellar behemoth, you'll need more than your eyes. At a distance of some 18,900 lightyears, it appears 5,100 times fainter than we can see without a telescope. If you have no telescope but would still like to see a celestial superstar, you're in luck. There's one shining in our night sky right now; it's one of the brightest up there and is named Betelgeuse. Betelgeuse sparkles brightly in the northeastern corner of Orion, the hunter, and you can see its orange light midway up in the southern sky after dark this week. With about 15-20 times more mass than our sun, Betelgeuse is known as a red supergiant star for good reason. While we could align 109 Earths across the face of our sun, we would need at least 700 suns to cross the face of Betelgeuse! Indeed, this star is so immense that if it replaced our sun at the center of our planetary system, Betelgeuse would engulf the orbits of Mercury, Venus, Earth and Mars, and stretch part of the way to Jupiter! Yet it appears as a simple point of light in our night sky because of its tremendous distance from us — some 3,100 trillion miles, or about 520 lightyears. Betelgeuse is easily one of the largest known stars, though its size fluctuates by as much as 60% as the star shudders and pulsates on its way to an eventual supernova explosion, thousands or millions of years from now. Or tonight. We just don't know.  I hope you'll step out under the night sky soon to meet this remarkable superstar for yourself! Visit Dennis Mammana at dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com. Learn More About Borrego Springs
February 25, 2026
By Dennis Mammana Week of March 1-7, 2026 Attention, night owls and insomniacs! The sky show this week is just for you! Much of North America is about to see the moon experience one of nature's most beautiful sky shows: a total lunar eclipse. A lunar eclipse occurs when the full moon slips into the Earth's shadow far out in space, either partially or completely, and that's just what will happen during the wee hours of March 3. Skywatchers throughout North America will see the start of this eclipse (weather permitting, of course), but depending on where you live, you may see only a portion of the sky show. In general, the farther west you live, the more of the eclipse you will see before the moon sets behind the western horizon. The eclipse begins at 12:44 a.m. PST (3:44 a.m. EST), when the moon enters the Earth's light outer shadow (known as the penumbra), but this shadow is so thin that no one will notice a darkening of the moon's appearance. Within an hour or so, that will change significantly. As the moon approaches the dark inner shadow of the Earth (known as the umbra), skywatchers will notice the eastern side of the moon beginning to darken slightly. The real show begins at 1:50 a.m. PST (4:50 a.m. EST) when the moon officially enters the umbra. No one gazing skyward will have any doubt that a "bite" has been taken out of the moon — a bite that will grow larger with each passing minute. For the next hour or so, the moon will dim as it slips more deeply into our planet's umbra, until 3:04 a.m. PST (6:04 a.m. EST) when it's completely engulfed and the total eclipse begins. Unfortunately, those in the far eastern part of North America may miss this since the moon will lie quite close to (or even below) the western horizon. During the total phase, the moon will take on a dim coppery hue. This occurs because sunlight passing through our atmosphere is reddened and bent inward toward the darkened surface of the eclipsed moon, now suspended eerily against the stars of Leo, the lion. Only those viewing from the Midwest to the West Coast will see mid-eclipse, which occurs at 3:33 a.m. PST (5:33 a.m. CST). Those in the Midwest may miss the end of totality at 4:02 a.m. PST (6:02 a.m. CST), however, as the moon will be setting in the west. The entire event will end at 5:17 a.m. PST (4:17 a.m. MST) with the moon approaching the western horizon for viewers in western North America. Unlike an eclipse of the sun, a lunar eclipse is perfectly safe to view without protective filters. Your eyes are all you need to enjoy the show, but you'll have even more fun viewing through binoculars or a small telescope. If the sky is cloudy that morning, or if you live where the eclipse won't be visible, you can watch a livestream of the sky show online. Visit timeanddate.com and click on "Sun, Moon & Space" at the top to find details for your location, as well as links to view the eclipse live online. Visit Dennis Mammana at dennismammana.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.  Learn More About Borrego Springs
By Dennis Mammana February 11, 2026
Among Eridanus’ prominent stars is Epsilon Eridani. Creators.com illustration
By Dennis Mammana January 22, 2026
The Great Orion Nebula is visible with the unaided eye.
By Jake Hinton September 15, 2024
Explore the best stargazing spots in Borrego Springs, California, with a stargazing map by the Dark Sky Coalition. Discover popular locations and tips for a perfect night under the stars.
Walk of the Cosmos
By Jake Hinton August 18, 2024
Experience the Walk of the Cosmos in Borrego Springs—a journey through the solar system in a beautiful desert park with playgrounds, sports courts, and stargazing opportunities.
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