Our Experts

David Baron is an award-winning science journalist, broadcaster, and author whose recent American Eclipse tells the true story of a total solar eclipse that crossed the Wild West in 1878 and inspired America’s rise as a scientific power. The book received the 2018 American Institute of Physics book prize, and the Wall Street Journal praised it as “a sweeping, compelling portrait of the scientific and social aspirations of Gilded Age Americans.” David is an avid umbraphile and intrepid traveler who has witnessed seven total solar eclipses [note: this should be changed to “seven” after July 2] and visited every continent multiple times. On a reporting trip to Antarctica in 1989, he set foot at the South Pole. A long-time science correspondent for NPR, David has also written for the New York Times, Los Angeles Times, and other publications, and has appeared on CBS Sunday Morning, BBC Newsnight, CNN, and ABC. His popular TED Talk on eclipse chasing (viewed more than 1.8 million times) has inspired many to experience totality for themselves.

David is currently working on his next astronomical study on Mars and Martians.  A detailed look at our historical love affair with the planet, and obsession with what may or may not dwell there.

Andrew graduated from Oxford University in England in 1978 with a BA in physics and in 1982 with a DPhil in Astrophysics. He worked on stellar atmosphere and stellar fundamental properties, including properties of atoms for interpreting stellar spectra. After several years as a post-doc at Oxford he moved to Sydney University in 1988 as a full professor in Astronomy and was part of the team building the Sydney University Stellar Interferometer, for measuring the sizes of stars. In 1998 he moved to JPL in Pasadena California to work on the Keck Interferometer project in Hawaii for NASA, linking the world’s two largest telescopes into a single instrument. After moving to GSFC in Maryland in 2010, he worked on the James Webb Space Telescope, and now works on the Laser Communication Relay Demonstration mission. 

Andrew Loves Elizabethan re-enacting including dancing and singing, and full authentic costume (with puffy pants!). He has also just obtained an authentic Napoleonic Hussar uniform.

Fred Espenak’s career as a NASA astrophysicist at Goddard Space Flight Center spans more than 30 years. His primary research involves the infrared spectroscopy of planetary atmospheres although he is better known as NASA’s eclipse expert Mr. Eclipse. Espenak is currently a scientist emeritus at Goddard and he maintains NASA’s official eclipse web site (eclipse.gsfc.nasa.gov) as well as his personal web site on eclipse photography (www.mreclipse.com). Fred has published numerous books and articles of eclipse predictions including the NASA Eclipse Bulletins series, and he is the co-author of the popular book Totality: Eclipses of the Sun. His magnum opus, the Five Millennium Canon of Solar Eclipses, includes a map of every solar eclipse occurring between 2000 BC and AD 3000. 

Espenak’s interest in eclipses was first sparked after witnessing a total solar eclipse in 1970. Since then, he has participated in 34 eclipse expeditions around the world including Antarctica. Fred’s eclipse photographs have appeared in both national and international publications, and he has lectured extensively on the Sun, eclipses and photography. In 2003, the International Astronomical Union honored him for his work on eclipses by naming an asteroid Espenak. Fred now lives in rural Arizona, where he spends most clear nights losing sleep and photographing the stars (www.astropixels.com).

Alex Filippenko is the Richard & Rhoda Goldman Distinguished Professor in the Physical Sciences, and a Miller Senior Fellow in the Miller Institute for Basic Research in Science (UC Berkeley). His accomplishments, documented in about 930 research papers, have been recognized by several major prizes, including a share of both the Gruber Cosmology Prize (2007) and the Breakthrough Prize in Fundamental Physics (2015). One of the world’s most highly cited astronomers, he is an elected member of the National Academy of Sciences (2009) and the American Academy of Arts and Sciences (2015). In 2017, he was selected for the Caltech Distinguished Alumni Award. He has won the most prestigious teaching awards at UC Berkeley and has also been voted the “Best Professor” on campus a record 9 times. Selected in 2006 as the Carnegie/CASE National Professor of the Year among doctoral institutions, he has also received the Richard H. Emmons Award for undergraduate teaching (2010).

He has also produced five astronomy video courses with “The Great Courses”; coauthored an award-winning astronomy textbook, and appears in more than 100 TV documentaries, including about 50 episodes of “The Universe” series. He has given about 1000 public lectures or other presentations, and he was awarded the 2004 Carl Sagan Prize for Science Popularization. An avid tennis player, hiker, skier, whitewater rafter, snorkeler, and scuba diver, he enjoys world travel and he loves to observe total solar eclipses (16 so far, all successful!).

For nearly five decades, Dennis Mammana has delivered the wonder and mystery of the cosmos to audiences around the world.

With a B.A. in physics and astronomy from Otterbein College and an M.S. in astronomy from Vanderbilt University, he has held positions at the Smithsonian Institution’s National Air & Space Museum, the University of Arizona, and San Diego’s Reuben H. Fleet Space Theater & Science Center.

Dennis is the author of six books on popular astronomy―including co-authoring the first-ever book about the search for extra-solar planetary systems―as well as hundreds of popular magazine and encyclopedia articles, scripts and blogs. Since 1992, he has written “Stargazers”, the only syndicated weekly newspaper column about astronomy.

As an accomplished night sky photographer, he is one of only six Americans invited to TWAN (The World At Night), an elite international team of the most highly acclaimed night sky photographers on the planet. His images have been featured nine times as NASA’s Astronomy Picture of the Day and dozens of times on the front page of Spaceweather.

A dynamic public speaker, Dennis has inspired and informed audiences on six continents. He has traveled to the Arctic and Subarctic more than 30 times to lecture about and photograph the aurora borealis (the northern lights) and has witnessed and photographed 18 total solar eclipses.

When not spending time with his head in the stars, he enjoys cooking home-style Italian food, sports, weight-training, tending to his Italian herb and vegetable garden, exploring the desert canyons in his Jeep 4×4, watching reruns of Gunsmoke, taking naps, and relentlessly pursuing the perfect Philly cheesesteak sandwich―not necessarily in that order.

He now works as an astronomy writer, lecturer, and photographer under the clear, dark skies of Southern California’s Anza-Borrego Desert. You can visit him online at dennismammana.com.

Saralyn Mark, MD, an expert on space medicine and a world renowned leader in women’s health, is an endocrinologist, geriatrician and women’s health specialist. As President and CEO of SolaMed Solutions, LLC, Dr. Mark has served as a medical and scientific policy advisor to the White House, NASA, HHS Office on Women’s Health, Gates Strategic Investment Fund, XPRIZE Health and Pandemic Alliance Brain Trust and other organizations dedicated to improving health on Earth and in space. She is also the President of iGIANT®, the only nonprofit accelerating gendered innovation in the world. She is also Director for Health Innovation for Star Harbor Academy. Dr. Mark holds 4 academic appointments including at Yale and Kings College-London in the Center for Human and Aerospace Physiology. Dr. Mark completed her residency and fellowships including designing the first women’s health fellowship at UCSF. She is author of Stellar Medicine: A Journey Through the Universe of Women’s Health which chronicles her adventures with the space program and her journey across all 7 continents which she incorporates into her podcast, Always Searching. She has published and delivered over 700 lectures and is a frequent health media expert including a monthly columnist for The Hill.. Dr. Mark was invited by the White House to testify about her work on precision innovation for the National Space Council which is led by the Vice President. She has received numerous awards including the NYU School of Medicine Alumni Leadership Award for her contributions to medicine, precision health and emerging technologies.

Robert Naeye is a former Editor in Chief of Sky & Telescope, the world’s most respected and influential popular astronomy magazine. Robert earned a master’s degree in science journalism from Boston University in 1992, and later worked on the editorial staffs of Discover and Astronomy magazine. He served as Editor in Chief of Mercury magazine (published by the Astronomical Society of the Pacific) from 2000 to 2003. He worked as a Senior Editor at Sky & Telescope from 2003 to 2007, before moving to NASA’s Goddard Space Flight Center to work as a Senior Science Writer for the Astrophysics Science Division. He returned to Sky & Telescope in June 2008 to serve as Editor in Chief. 

Robert is the author of two books: Through the Eyes of Hubble: The Birth, Life, and Violent Death of Stars (Kalmbach, 1997) and Signals from Space: The Chandra X-ray Observatory (Turnstone, 2000). He has contributed to two other books, and has won several awards for his writing and outreach activities. He has traveled four times to Hawaii and has visited all the populated islands except for Lanai and Niihau. He has also served as an astronomy lecturer on tours to Chile, Iceland, China, Australia, Easter Island, Iran, and Libya.

William Sheehan is one of the world’s leading students of the planet Mars. In June 2001, he and a team of observers in the Florida Keys predicted and observed Martian flares at Edom Promontorium, observations which have contributed an important chapter in the search for Martian water in near-equatorial regions. A major area of his astronomical interest has always been the history of and interpretation of visual observations of planetary markings such as those of Schiaparelli and Lowell of the “canals” of Mars. 

Sheehan’s first book, “Planets & Perception”, published in 1988, was a Book-of-the-Year Selection of the Astronomical Society of the Pacific. Other critically acclaimed books include: “Worlds in the Sky” (1992), “The Immortal Fire Within: the life and work of Edward Emerson Barnard” (1995), and “In Search of Planet Vulcan” (1997). 

Sheehan is a contributing editor to “Sky & Telescope” and to “Mercury” magazines. He is also a 2001 Fellow of the John Simon Guggenheim Memorial Foundation, awarded for his work-in-progress: “The Structure and Evolution of the Milky Way Galaxy.” In 2001-2002, he was a Visiting Research Associate at the Lick Observatory and a Visiting Professor of Astronomy at the University of the Witwatersrand, Johannesburg, South Africa.

Dr. Seth Shostak claims to have developed an interest in extraterrestrial life at the tender age of ten, when he first picked up a book about the solar system. This innocent beginning eventually led to a degree in radio astronomy, and now, as Senior Astronomer, Shostak is an enthusiastic participant in the Institute’s SETI observing programs. He also heads up the International Academy of Astronautics’ SETI Permanent Study Group. 

In addition, Shostak is keen on outreach activities: interesting the public – and especially young people – in science in general, and astrobiology in particular. He’s co-authored a college textbook on astrobiology, and continues to write trade books on SETI. In addition, he’s published nearly 300 popular articles on science, gives many dozens of talks annually, and is the host of the SETI Institute’s weekly science radio show, “Are We Alone?” Shostak’s latest book is “Confessions of an Alien Hunter : A Scientist’s Search for Extraterrestrial Intelligence” ( National Geographic ). 

Dr. Shostak is host of radio’s “Big Picture Science.”

Planetary astronomer Mark Showalter is rabid about rings. While everyone knows about Saturn’s spectacular ring system, it’s often forgotten that Jupiter, Uranus, and Neptune are also encircled by fainter and narrower rings. Each of these systems interacts closely with a family of small, inner moons. Showalter works on some of NASA’s highest-profile missions to the outer planets, including Cassini, now orbiting Saturn, and New Horizons, which flew past Jupiter en route to its 2015 encounter with Pluto. Known for his persistence in planetary image analysis, Mark’s work on the earlier Voyager mission led to his discovery of Jupiter’s faint, outer “gossamer” rings and Saturn’s tiny ring-moon, Pan. 

Mark was recently granted three more years to study the system of rings and moons orbiting Uranus with the Hubble Space Telescope. He has been leading a team of astronomers in this investigation off and on since 2002. This work has already led to the discovery of two small moons and two faint rings. He enjoyed the opportunity to name the moons “Mab” and “Cupid,” after characters from Shakespeare’s plays. 

Marcie Smith received her masters in Aeronautics and Astronautics Engineering at Stanford University in 1980 and has been fortunate to have worked in unmanned planetary science flight operations ever since. She began as a flight operations engineer for the Pioneer program, and has managed flight operations for Galileo Probe, Lunar Prospector and Gravity Probe B. She is currently the Mission Director for the Kepler mission. Kepler is designed to survey a portion of our region of the Milky Way galaxy to discover dozens of Earth-size planets in or near the habitable zone and determine how many of the billions of stars in our galaxy have such planets. 

Marcie is also a private pilot and flies a Cessna 182. She is an active member of the 99s – the International Organization of Women Pilots, and whenever she can flies for Angel Flight, an organization where private pilots use their airplanes to fly patients to medical appointments.

Dr. Michelle Thaller is an astrophysicist with over two decades of science communication experience. Her research involves the lifecycles of stars, and she has worked at the Jet Propulsion Laboratory and Goddard Space Flight Center. 

Originally from Waukesha, Wisconsin, Michelle obtained a Bachelor’s degree in astrophysics from Harvard University. Specializing in high-resolution velocity measurements of binary stars, her honors thesis laid some of the groundwork for the recent detection of planets around other stars. In 1997, Michelle obtained a Ph.D. from Georgia State University. Michelle’s dissertation work included the first-ever detection of a “stripped core sub-dwarf” (a star that has been almost completely stripped of its outer envelope by the gravitational pull of a companion star) as well as the discovery and characterization of the phenomenon of colliding stellar winds in several massive binary star systems. 

During her research, Michelle has used both ground and space-based telescopes, including Kitt Peak National Observatory, Mount Stromlo and Siding Spring Observatories (in Australia), the International Ultraviolet Explorer, the Hubble Space Telescope, and ROSAT. She is currently a senior scientist on the Spitzer Space Telescope, a satellite that views the universe entirely through infrared, or “heat” light.

Michelle dedicates more than half her time to public education and outreach, and acts as one of the spokespeople for Spitzer and other NASA missions at the Jet Propulsion Laboratory. Michelle has been featured in numerous media programs, including three documentaries on NASA science that are playing at the National Air and Space Museum, an educational program about finding new planets that is playing at the Rose Center of the Museum of Natural History, and a video infrared demonstration showing at the Adler Planetarium and the Boston Museum of Science. She has appeared in many television science programs, including How the Universe Works and Space’s Deepest Secrets.  Michelle has done two TEDx talks about astronomy and has hosted the podcast Orbital Path on public radio.