Jay Pasachoff, an astronomer who traveled the world for more than 50 years to witness 74 solar eclipses and was one of the world’s foremost experts on such views from the sky, has died aged 79.
Pasachoff, professor of astronomy at Field Memorial and director of the Hopkins Observatory at Williams College, died Sunday, Nov. 20 at his home in Williamstown, Mass. His wife Naomi Pasachoff identified lung cancer as the cause of death.
Pasachoff wrote about his passion for solar eclipses in a Editorial from the New York Times (opens in a new tab) in 2010: “We are umbraphiles. After standing in the shadow, the shadow of the moon, during a solar eclipse, we are driven to do so again and again, each time the moon moves between the Earth and the Sun.”
Related: Chasing Solar Eclipses: Q&A with Jay Pasachoff
After completing his doctorate in 1969 with a thesis entitled “Fine Structure in the Solar Chromosphere”, Pasachoff developed an incredible track record for identifying the best observing sites for eclipses. This included calculating where the clearest sky would be available to view the totality phase of an eclipse. Familiarity with weather data also allowed Pasachoff to become known for his accurate weather forecasts.
Born on July 1, 1943 in New York City, Pasachoff’s passion for astronomy began at an early age with trips to the Hayden Planetarium at the American Museum of Natural History. While attending Bronx High School of Science, Pasachoff began building telescopes.
After graduating in 1959 at age 16, Pasachoff attended Harvard University. There he took a course in astronomy taught by Donald Menzel, one of the first astronomers and theoretical astrophysicists in the United States and also an expert on solar eclipses.
Pasachoff observed his first solar eclipse in 1959, on November 1. In his 2010 New York Times article, the astronomer detailed his description of the event from his diary as follows: moon covered the sun and the sky darkened, the solar corona outlined the moon in white. I was addicted.”
Pasachoff earned bachelor’s, master’s, and doctorate degrees from Harvard in 1963, 1965, and 1969, respectively. Pasachoff conducted postdoctoral research at the Harvard College Observatory in 1969, then took a position at the California Institute of Technology before joining Williams College in 1972.
He spent the next half-century chasing eclipses around the world, his passion never waning. “Every time is like going to Game 7 of the World Series with the score tied in the ninth inning,” he told Fox News in 2016.
Solar eclipses did not represent all of Pasachoff’s work with the sun, Nevertheless. The astronomer studied the sun’s outer atmosphere, known as the the crown, which only becomes fully visible during eclipses. (The corona is washed away by light from the underlying layers and can only be seen when the moon blocks the solar disk.)
The corona is much hotter than the solar surface, for reasons that scientists are I always try to practice. Along with Steven Souza and Bryce Babcock, Pasachoff conducted experiments to study the million-degree temperature of the solar corona and find out what heats the sun’s atmosphere to such extreme temperatures.
Pasachoff also studied in detail the passage of the innermost planets of the solar system Mercury and Venus across the face of the sun. In July 2004, for example, Pasachoff and a team from Williams College observed the first transit of Venus across the sun in 122 years, one of the rarest planetary alignments in the solar system. Pasachoff also witnessed a transit of Mercury through the sun in 2006.
Related: Solar System Planets, Order and Formation: A Guide
Arguably Pasachoff’s greatest contributions to science, however, were his public outreach efforts encouraging the general public to observe cosmic events regardless of their skill level.
In 2003, he received the American Astronomical Society (AAS) Education Award for “his eloquent and informative writing of textbooks from undergraduate through college; for his dedication to teaching generations of students; for for sharing with the world the joys of observing eclipses; for his many popular books and articles on astronomy; for his intense advocacy for science education in various forums; for his willingness to go to educational nooks where no astronomer has gone before.”
In 2012, Pasachoff received the Jules-Janssen Prize from the Société Astronomique de France for his research, teaching and popularization of astronomy.
In a similar vein, Pasachoff received the 2019 Klumpke-Roberts Prize from the Astronomical Society of the Pacific in 2017 for his contributions to the public understanding and appreciation of astronomy.
A Klumpke-Roberts Prize nominator wrote of Pasachoff’s activities in preparing for solar eclipses: “It is during these times that Jay becomes the chief cheerleader of astronomy, enabling more and more people to take an interest and engage in the field.”
In a Q&A 2017 with Quanta (opens in a new tab)Pasachoff said: “I think if we take millions or tens of millions of school kids out to watch the eclipse – it’s so amazing to be out during totality, and it’s such a dazzling sight, perhaps they could be persuaded to pay more attention to their studies.
“Who knows? In the long run, we might get more scientists out of it, more great discoveries.”
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