Volume XXVII Number 1
Photo © Tyagan Miller
The Young Star Cluster NGC 2264.
This image of the young star cluster NGC 2264 was obtained by combining individual images obtained through B (blue), H-alpha, and I (near infrared) filters using the WIYN .9-meter telescope on Kitt Peak in Arizona. The H-alpha filter, which isolates the glow of hot hydrogen gas, allows us to see the nebulosity surrounding this young star cluster. The B and I filters pick out the bright young stars of the cluster. This astronomical image was obtained as part of a College of Arts and Sciences Freshman Seminar at Indiana University Bloomington led by Catherine Pilachowski. Students in the course participated in remote observing using the telescope in Arizona and selected the targets for observation and the filters used.
Speaking Out for Space Science
Here we are in the golden age of astronomy, and most of us are unaware. That the U.S. government could do more to inform us of breakthroughs in space science over the past 30 years is a point Catherine Pilachowski recently traveled to New York City to make. Speaking on behalf of the American Astronomical Society, of which she was then the president, Pilachowski addressed the scientific panel that helped formulate President George W. Bush's "Moon, Mars, and Beyond" initiative.
Pilachowski, who holds the Daniel Kirkwood chair in astronomy at Indiana University Bloomington, told the President's Commission on U.S. Space Exploration Policy that it's essential to awaken public enthusiasm for the vast knowledge to be gained through space research.
"Understanding our universe, how it formed, how it changes over time, the details of interaction between its various constituents, and how all the myriad objects change is fundamentally inspirational to humans," Pilachowski said in her presentation. She encouraged the panel to develop a long-term vision, with a presence on the moon and operations on Mars as only some of the goals that our government should plan to achieve.
Back in Bloomington, Pilachowski reflects on the history of the National Aeronautics and Space Administration (NASA) and what strategies the agency will employ to meet Bush's objectives, which include making space exploration a national priority, increasing private sector involvement, and boosting education in science, mathematics, and engineering. "The Apollo program, occurring as it did during the Cold War, achieved its goals of sending crewed missions to the moon and demonstrating to the world the strength of our political and economic systems," she says. "But after the Apollo program wound down, it was clear that NASA's space program no longer had a driving goal." The subsequent focus on orbiting the earth in space shuttles, Pilachowski says, has never really jelled as an important national priority."
To Pilachowski, NASA's post-Apollo contributions to basic science are much more interesting than the space shuttle missions. "The Hubble Space Telescope and many other scientific satellites and observatories have yielded a huge amount of progress in understanding the universe," she says. She ticks off an impressive list:
"We've been able, for example, to make detailed measurements of the cosmic microwave background radiation and to detect the light of extraordinarily distant stars and galaxies. We've made the discovery that the universe is accelerating, because of some unknown force we've called dark energy but haven't even begun to understand. And the ingredients of the universe we know about--the matter, the hydrogen and other gases, the stars, the galaxies--we now know all of that is less than five percent of what the universe is made of. These are extraordinary discoveries."
Pilachowski hopes for more discoveries of such magnitude through "Moon, Mars, and Beyond," which will search for signs of possible life on Mars and Jupiter and thus lead to a greater general understanding of the origins of life. She also expects much from robotic explorations beyond our solar system in search of planets around other stars. These extrasolar planets" are one of Pilachowski's research interests.
"The new vision gives NASA a deep sense of where its crewed and robotic space explorations should be headed," she says. "I think almost everyone agrees that this is a good direction.
"At the same time," Pilachowski continues, "the astronomical community wants to make sure that NASA's vision continues to include the broader exploration of space--understanding where that 95 percent we don't know about comes from, understanding the origin and evolution of the whole universe. Those are really important questions."
As excited as she is about the prospect of answering these questions, Pilachowski acknowledges that many of her fellow citizens see investment in a space program as frivolous, a distraction from more pressing concerns. "My students often say this," she says, "and I'm sympathetic. There certainly are serious problems here on earth. But I think that if we don't invest in space exploration, we won't be able to solve those problems. Space exploration brings so much to our culture, because it inspires us. In the social arena, we learn so much from the international participation. We've also gained so much useful technology."
The technology Pilachowski most often employs includes telescopes at the Kitt Peak National Observatory near Tucson, Arizona, and at the Cerro Tololo Inter-American Observatory in Chile. She also uses spectrographs to analyze the chemical content of stars in support of her other main research area, the history of stars in our Milky Way galaxy.
"I study the beginnings of systems of stars--star clusters--which are identifiable groups of stars that form together and stay together for a long time," Pilachowski explains. "The properties of a galaxy at the time it formed are preserved in the structure of the star clusters, in their orbit around the center of the galaxy and in their chemical makeup. By studying the properties of star clusters, by looking at star clusters of different ages, we can begin to unravel the formation and early history of the Milky Way."
Learning as much as possible about the birth of the Milky Way is a key to understanding the beginning of the universe as a whole, Pilachowski says, because our galaxy formed very shortly after the Big Bang, approximately 14 billion years ago.
"When the universe first formed, it consisted almost entirely of hydrogen," she says. "Most elements, almost all of them, formed through the nuclear processes that go on inside the stars. Those stars explode, they send their matter out into space, and new stars form, enriched in the metals that were formed in earlier stars. I look at that process of enrichment--how all those materials that we're made of, all of the atoms, were produced in the stars."
Pilachowski's research on extrasolar planets emerges from her investigations of star and galaxy formation. "I use star clusters as my laboratory for studying the evolution of solar systems," she says. "I look at very young star clusters and try to identify properties of solar systems within those clusters. Astronomers have found more than 100 planets around stars outside our solar system."
Pilachowski says that most of these planets resemble Jupiter. "They're massive, gas-giant planets. Their orbits are very close to the stars, so close that if they were in our solar system, they would be orbiting inside the orbit of Mercury."
Apparently, these gigantic planets migrate toward their suns, obliterating any smaller planets in their path. Earth, however, is unlikely to be overrun by Jupiter, Pilachowski says. "This solar system appears to be very stable. The processes that would cause that kind of migration seem to happen very early in the life of a solar system, probably in the first 10 or 100 million years that a solar system exists. If Jupiter has survived out at its great distance up to now, it's probably because the mechanisms that cause orbits to change eventually disappear."
So far, no planets like Earth have been found, but Pilachowski predicts that such discoveries will be made within the next 20 years.
"Our ability to find planets is still very primitive," she says. As our techniques improve, we expect to find more planets like Jupiter, planets that are orbiting at several times the distance between the Earth and the Sun. And eventually we expect to find Earth-like planets.
"NASA's mission includes being able to take pictures and spectra of those types of planets," she adds, "and to discover whether those planets have atmospheres, which would be an indication of life. If we can find oxygen, then there's a really good chance that there could be life similar to that on Earth."
Pilachowski earned a Ph.D. from the University of Hawaii, then joined the Kitt Peak Observatory, where she conducted research for 20 years, and served as the project scientist for the Wisconsin-Indiana-Yale-NOAO consortium, or WIYN.
Because of IU's partial ownership of the WIYN telescopes, Pilachowski also worked closely with many scientists from the university's astronomy department, so when the opportunity to teach at IU occurred, it seemed like a natural progression. "I had begun to feel an obligation beyond just to astronomy," she says. "I wanted to give something back in return for all the education I've received."
Pilachowski's drive to reach out to larger audiences takes many forms. For example, she and her IU colleagues sponsor various hands-on scientific events for children. "It's really easy to get kids excited about space exploration," she says. "The 10-year-olds are instinctively curious about space."
Her greater challenge is to stimulate that level of interest in undergraduate college students. "I want to teach graduate students, but I also want to teach introductory astronomy students who may be taking their only college science course, to help them see how fascinating science is," she says. "Nationwide, there are a couple hundred thousand students a year who take astronomy in college. Through them we can have an impact; we can help the public understand what space exploration is about and what its value is, not just for astronomers, but for society at large."
How does Pilachowski do this in her introductory classes? "I get the students involved in observing at telescopes," she says. "The astronomy department has a remote observing center in Swain Hall, so the students have video access to the WIYN observation equipment. They can see what the astronomers there are doing in real time."
Pilachowski's undergraduates are also involved in a research project that is searching for novae (exploding stars) in the Andromeda galaxy, the Milky Way's neighbor. The data that we get from WIYN is available on our Web site so the students can make original discoveries," she says. Pilachowski makes observations on the WIYN telescopes during two or three brief visits a year. Graduate students and undergraduates accompany her on these trips or travel there independently.
Each summer since she joined the faculty in 2001, Pilachowski has expanded her outreach by delivering a lecture at the IU Alumni Association's Mini University. This year the topic was "The Past and Future History of the Sun." Pilachowski and her audience considered concepts such as matter and antimatter, nuclear fusion, and planetary nebulae. Though her listeners may not have grasped every detail, their questions were lively and perceptive. After projecting images from Hubble that she characterized as "gorgeous" and describing the black hole into which the universe will eventually collapse, she concluded her presentation to profuse applause.
Once again, Pilachowski had succeeded in demonstrating that space science is, in her words, "a creative and human activity."
Karen Grooms is senior editor in the Indiana University Office of Publications in Bloomington.