“Galileo didn’t have to be Galileo,” Michelle Thaller, an assistant director at NASA, said of the fact that the scientist became one of the most famous astronomers largely by chance. Four hundred years ago this year, Galileo Galilei unveiled his telescope in Venice to the city’s elite as a tool for observing not just the incoming ships, but also the heavens. In honor of that event’s impact, the United Nations Educational, Scientific and Cultural Organization (UNESCO) has declared 2009 the International Year of Astronomy.
In keeping with that theme, the annual fall lectures sponsored by the College’s chapter of the national scientific research society Sigma Xi featured a pair of lectures by Thaller, who discussed Galileo’s work on Thursday and the future of science at NASA on Friday.
Thaller is a recent addition to NASA’s Goddard Space Flight Center from NASA’s Spitzer Science Center at the California Institute of Technology; she now serves as Goddard’s assistant director of Science Communication. In her first lecture on Thursday, titled “Galileo: 400 Years of Astronomy,” Thaller explored the myths and facts behind one of the most famous astronomers of all time. She opened by placing Galileo among the world’s first modern scientists, a position that, according to Thaller, “has its positives and negatives.”
Thaller noted that Galileo observed and trusted the physical world around him as a researcher. He also found himself embroiled in issues of power, politics and funding, obstacles that Thaller could readily discuss from her personal experience at NASA.
She said that given the moment of technological advancement and trends in academic inquiry during that period of history, it was only a matter of time before someone took a Dutch spyglass to the heavens.
In fact, Thaller pointed out that English academic Thomas Harriot observed the moon and even made more accurate sketches four months before Galileo. The difference between the two men was that Galileo, brash and theatrical, proved better at popularizing himself.
Thaller elaborated on the repercussions of Galileo’s style of self-advocacy, which led to the confrontation that has helped give the Roman Catholic Church such a poor reputation with respect to science.
She explained that this narrative of the Church’s inquisition against Galileo actually removes his experience from the intellectual, political and personal context that surrounds it. Indeed, partly because of Catholic leader Thomas Aquinas’ interest, the views of Aristotle and the Ptolemaic view of a geocentric universe had come to dominate intellectual life in Galileo’s time.
The Church was not completely hostile to scientific inquiry or even to the discoveries of Galileo, and one of the primary reasons the Church decided to prosecute Galileo was to protect its own astronomers, with whom Galileo had developed a hostile rivalry. Ironically, the straw that broke the camel’s back for the Church astronomers was Galileo’s mockery of their assertion that the asteroid belt was further from Earth than Mars â€“ one of several topics on which Galileo was, as Thaller put it, “patently wrong.” Politics and personality, as in many scientific controversies, drove Galileo’s fate, she explained.
Thaller’s second lecture fast-forwarded four centuries to the present and across the Atlantic to the current work of Goddard Space Flight Center. In her lecture, “The Universe is About to Change: Science at NASA,” she discussed the current work of NASA, the future discoveries it hopes to make and the challenges it faces. Beginning with an overview of the center and her role there, Thaller focused on several major projects.
The biggest project at the moment relates to monitoring Earth, an undertaking that Thaller acknowledged as a result of the Obama administration’s support and the availability of funding for research on the impact of human activity on the environment. Within that project, Goddard scientists have been tracking carbon levels in the atmosphere and monitoring ocean conditions and aquifer levels.
The study of freshwater levels in the aquifers that humans use employs a particularly interesting pair of satellites referred to as GRACE, for the Gravity Recovery And Climate Experiment. These two satellites communicate with each other via laser to record changes in gravitational pull, which in turn reveals information about changes in aquifer levels.
One example of GRACE’s capabilities that Thaller characterized as extremely important for the next few years is the monitoring of water levels in northern India. Aquifers in that region serve many millions and are depleting rapidly, which will result in a freshwater shortage in the coming years.
Another area of inquiry â€“ one with a focus slightly farther from home â€“ that Thaller strongly emphasized was the search for extraterrestrial life. In terms of the likelihood of its existence and scientists’ ability to find that life, Thaller explained that she was very optimistic. She cited the presence of warm cave systems on Mars, liquid water on Saturn’s moon Enceladus and the discovery of Earth-like planets outside our solar system as evidence of that probability.