Astronomy has lost one of its most assiduous calculators of eclipses with the passing of astronomer Fred Espenak.
On April 15, 2025, Espenak announced on his Facebook page that he had idiopathic pulmonary fibrosis, his health was declining rapidly, and that he would immediately be entering hospice care. Doctors determined that the disease had progressed too far for a lung transplant. He passed away peacefully on Sunday, June 1 at his home in Portal, Arizona. He was 71.
Fred was a well-known and highly regarded expert on eclipses, so much so, that he became almost as well known by his nom de plume, “Mr. Eclipse.” He first got interested in astronomy when he was 8 years old. “I was visiting my grandparents on Long Island when a neighbor boy invited me to see the moon through his new telescope. Just one look and I was hooked! After a relentless six-month campaign, my parents conceded to my request and I received a 60 mm Tasco refractor for Christmas,” Espenak wrote in his biography on Astropixels.com.
Fred first became attracted to eclipses, when, at the age of 9, he witnessed a partial eclipse of the sun from the New York metropolitan area. Seven years later, on March 7, 1970, when the moon’s dark shadow tracked along the Atlantic Seaboard, he was able to coerce his parents to borrow the family car where he traveled by himself to North Carolina and witnessed his very first total solar eclipse. Initially, he expected it to be a once-in-a-lifetime experience, but when totality ended, Fred knew he had to see another total eclipse. Indeed, that 1970 eclipse would be the first of 31 totalities he would journey to see during his lifetime.
And yet, while Fred ultimately grew up to become a full-fledged astronomer, his professional research didn’t actually involve eclipses. He earned his bachelor’s degree in physics at Wagner College in Staten Island and later obtained his master’s degree in Ohio at the University of Toledo, based on studies he did at Arizona’s Kitt Peak Observatory of eruptive and flare stars among red dwarfs. Thanks to his background in physics and computer programing, Fred landed a job with a software company holding NASA contracts.
That led to his writing data analysis programs for satellites and a stint as a telescope operator for NASA’s International Ultraviolet Explorer spacecraft. From this, he was hired by the Infrared Astronomy Branch at the Goddard Space Flight Center in Greenbelt, Maryland. Fred’s research focused largely on planetary atmospheres using an infrared spectrometer that he and his colleagues took first to Kitt Peak in Arizona and then to NASA’s Infrared Telescope Facility on Mauna Kea, Hawaii. He coauthored papers on winds on Titan, ethane in Jupiter’s atmosphere, ozone on Mars, and hydrocarbons in the outer planets.
Fred retired in 2009. But he truly made his mark as a tireless calculator of eclipses of both the sun and moon. Up until 1994, the U.S. Naval Observatory routinely issued special circulars in advance of major solar eclipses. When funding for these circulars came to an end, Fred picked up the eclipse baton and with the help of Canadian meteorologist Jay Anderson, produced their own eclipse circulars, funded under the auspices of NASA. Together, they published 13 circulars which contained timings, for hundreds of locations, predictions for what the moon’s edge would look like, and maps that showed the path of totality. Distribution of these free circulars ended with Fred’s retirement from NASA.
But it didn’t stop there. Fred then turned to private publishing as well as setting up three websites, AstroPixels.com, MrEclipse.com, and EclipseWise.com which to this day all remain invaluable resources with extensive information about numerous celestial phenomena, including detailed maps and timing of past and future lunar and solar eclipses. Fred gave public lectures on eclipses and astrophotography. Astronomical photographs taken by him have been published in National Geographic, Newsweek, Nature, and New Scientist.
For his astronomy and solar eclipse outreach, the International Astronomical Union named Asteroid 14120 Espenak after him in 2003.
Fred also teamed up with another remarkable eclipse calculator, his long-time mentor and friend, Jean Meeus of Belgium and together in 2006 they published the Five Millennium Canon of Solar Eclipses, which covers all types of solar eclipses from 2000 BC to AD 3000, and the similar Five Millennium Canon of Lunar Eclipses in 2009. And many other eclipse guides — 30 in all — followed. Among them, the Guide for the Total Solar Eclipse of 2045 which highlights a long-duration (6+ minute) solar eclipse that crosses the United States from coast-to-coast.
Fred was also the progenitor of the U.S. Stamp which commemorated the “Great American Solar Eclipse of 2017.” And earlier, in 1997, Mongolia used an image of his eclipse track from a NASA Circular in a commemorative of the 1997 eclipse.
If you asked him which of his 31 eclipses was the most rewarding, he would point to the one that occurred over India in October 1995:
“I chanced to meet a high school chemistry teacher named Patricia Totten. Now I’m not the sharpest knife in the drawer when it comes to the fairer sex, so it took me a few years to fully appreciate this remarkable woman. She shared my passion for eclipses, science and photography as we traveled the world together. Long story short, we eventually got married in 2006.”
It was Pat who encouraged Fred to find a place with dark skies for a retirement home, so he bought property at Arizona Sky Village in Portal and spent most of his free time under the starry skies visible from his Bifrost Astronomical Observatory.
On a personal note, I first met Fred about 50 years ago at a function that was held at the Wagner College Planetarium in Staten Island, where he served as a volunteer. At the time, I was doing something similar at the Hall of Science Planetarium in Flushing, N.Y. But it wasn’t until years later, when Fred began, in earnest, to publish and circulate his eclipse bulletins, that I became aware of his expertise in eclipse calculations.
I owe him so much for helping me in my own attempts to educate the public about the phenomena of eclipses. My greatest regret is that we never had the opportunity to spend time together in the moon’s umbra. I’m sure it would have been a blast!
I wish you Godspeed my friend. I know you have taken a safe voyage and I hope to see you again someday.
Joe Rao serves as an instructor and guest lecturer at New York’s Hayden Planetarium. He writes about astronomy for Natural History magazine, Sky and Telescope and other publications.
