|Lucy McFadden in July 2006|
Many children dream of becoming astronauts when they grow up. Not Lucy McFadden: she dreamed of becoming a lepidopterist, a scientist who studies butterflies. However, her interest in nature led her to an entirely different career, one that people do dream about- astronomy. McFadden, who is based out of the University of Maryland, researches the evolution of the solar system through planetary bodies like asteroids and comets, and collaborates with The National Air and Space Administration (NASA) on some of its most exciting missions.
McFadden has attributed her decision to embark on a career in the sciences to her rebellious nature. Everyone in her family worked in business and she wanted to do something new. "This was the late 1960s- everybody was rebellious!" she laughs. Her development had more fuel behind it than simply a desire to be different, however: A wonderful science teacher at McFadden's high school, Concord Academy in Concord, Massachusetts stoked her passion for science by giving her supervisory responsibilities in the lab and encouraging her interest in the natural sciences.
McFadden's formal scientific inquiry began her first year at Hampshire College, a private liberal arts college founded in 1970 to encourage multi-disciplinary study and student-initiated projects. Freshman year, McFadden placed Optical and Radio Astronomy on her wish list of courses, simply on a whim. She was placed in the course through a lottery system. Surprised to find she loved it, she chose to take more courses in astronomy and geology, a related science that studies the history of the earth through rocks. McFadden's senior thesis involved studying the planet Jupiter's unique configuration of satellites. An astronomer from the Massachusetts Institute of Technology, Professor Tom McCord, supplied instruments for the project, and, impressed by her budding talent, offered McFadden a chance to study at MIT.
The wonderful mentor McFadden found in McCord provided not only the jumpstart for her career in astronomy, but also influenced its direction. "He was incredible," says the grateful protege.
"He showed faith in me despite the fact that I came from a non-traditional background. My degree was in Natural Sciences, which gave me a very general background. Hampshire didn't give grades, and I never took the graduate entrance exam. I was admitted to MIT as a special student. My route was definitely not direct, the way others were. Many students in the program had been obsessed with rockets since they were young. Tom mentored me and helped me navigate the scientific arena, as he did with other young women who were underrepresented in the hard sciences at that time."
|The Mauna Kea Observatory (The University of Hawaii)|
After spending three years at MIT, McFadden and most of her entire lab followed McCord to his new post at the University of Hawaii, the institution that awarded her a PhD in geology and geophysics. Studying in Hawaii was not only wonderful because of the beautiful surroundings, but also because the university boasts one of the world's best locations for stargazing, the high-altitude observation point at Mauna Kea, and a very powerful telescope with which to view the sky. "The observatory at Mauna Kea is the best in the world," says McFadden. "It is a very special place. Other groups have established observation points there- Japan, Canada, France, the University of California system- it is a true telescope city. We are grateful to the people of Hawaii for sharing their special place for understanding the mysteries of the Universe."
McFadden's doctoral work remains to her some of the most exciting. She embarked on the first ever study of the spectral properties of asteroids orbiting near Earth; to do this, she measured the strength of sunlight reflecting off the asteroids across a range of colors to determine their composition. No one had researched near-earth asteroids before- the technology needed to do so was pretty new at the time of McFadden's work, and scientists simply didn't think these celestial bodies were very important. McFadden's results showed that they were: near-earth asteroids are made of the same materials as other, more distant asteroids, which means that all asteroids likely originate from the same asteroid belt in space. She also determined that asteroids are the basic units of the inner solar system: all of the asteroids appeared to be small planets that never fully formed. At the same time McFadden was studying the composition of near-earth asteroids, her colleagues discovered that these asteroids are responsible for the craters on the Moon and the Earth! They still have the ability to strike the moon and potentially the Earth, but thankfully this possibility is rare.
Fascination with the evolution of the solar system has followed McFadden throughout her career. She has worked with the California Institute of Technology's Jet Propulsion Lab and at NASA's Goddard Space Flight Center in Maryland. Other work with NASA has included the first long-term close look at an asteroid, 433 Eros, taking measurements of its mass, composition, gravity, and other properties, as well as a study of a comet's collision with Jupiter.
|A spacecraft awaiting lift-off (Lucy McFadden)|
McFadden also participated in NASAï¿½s Deep Impact Mission, a planned spacecraft collision with Comet Tempel 1 designed to "turn the comet inside out" and study its composition. Another spacecraft passed the comet as the collision took place, and NASA coordinated with observers on the ground worldwide to watch the collision through their telescopes and share their observations. McFadden and other scientists are still analyzing data from the 2005 mission, much of which was unexpected. "For example, before the impact, we observed rapid brightening of the comet over the course of an hour, which then decayed quickly." She explains: "This is called outbursting, and we've never seen this occur repeatedly in an individual comet while we could observe it up close. We are trying to determine why this happened. Also, we can determine the composition of the comet through spectroscopy, and the surface we saw was also unexpected- the terrain was much more varied than we thought." Spectroscopy is the method through which astronomers can determine the composition of a celestial body. Light particles, or photons, interact with surface or gas and dust surrounding the comet in such a way that a spectral signature or fingerprint is produced. By looking at the picture of these wavelengths astronomers can see what the comet is made of and deduce the physical processes that formed them. The NASA team was able to perform this analysis despite the fact that the impact released microscopic grains into the atmosphere that were not only unexpected but also long-lasting. "We couldnï¿½'t see the crater itself, but we still obtained our objectives," says McFadden. Colleagues have written a proposal for a future mission to observe the crater after the dust has cleared.
McFadden also supervised the Education and Public Outreach program for the Deep Impact Mission. She directed the development of materials for students to learn how to observe comets and Comet Tempel 1 during the Deep Impact Mission. A range of groups, including astronomy clubs in schools and astronomy camps, used these materials. "This approach- using the Deep Impact Mission to capture students' attention- is called 'event-based learning,'" says McFadden, who on the day of our interview was scheduled to staff a telephone conference call with Girl Scout leaders to discuss the Deep Impact Mission as an activity to be used for award of the "Activities for Science" badge.
"Working at the University of Maryland has given me opportunity to help train the next generation of scientists," says McFadden, herself mother to two college-aged girls with her husband, a NASA scientist whom she met while studying in Hawaii. One of her daughters is interested in the natural sciences too, and clearly, she has big shoes to fill. Above all her other accomplishments, McFadden received a huge honor: the naming of a planet after her, Minor Planet (asteroid) 3066 McFadden.