Pondering the Universe:
Physics 103 Goes on a Cosmic Adventure
Galileo saw the phases of the moon through a makeshift telescope 400 years ago. What he saw of the moon and planets eventually would lead him to challenge common beliefs about the universe.
Today, students in Associate Professor Duilia de Mello’s astronomy class study the phases of the moon in the night sky above Catholic University’s campus. What they see leads them to better understand the universe in which they live.
Each night for a month, students in Physics 103 observe the moon in a project that requires them to sketch the phases and make notations about the moon’s altitude and the direction from which they view it.
Much to De Mello’s dismay, she finds that many young people never look up to see the beauty that she has studied for more than 20 years. “The moon project gives students an awareness of the sky,” she says.
“As with all Dr. De Mello's assignments,” says freshman John McCarthy, “it is not about the theory, but rather what you take from it. After that project, every student was able to look at the moon with new appreciation.”
Physics 103, an astronomy course for nonscience majors, is an overview of the universe that begins with a history of astronomy and telescopes and covers the solar system, stars and evolution of the universe.
De Mello was nicknamed “Mulher das Estrelas” by the media in her native Brazil after she discovered a supernova in 1997. In a Hannan Hall classroom, this “Woman of the Stars” extends her arms in what seems like an embrace of the universe as she lectures to 40 students. “Brilliant!” she proclaims as an image of our own Milky Way galaxy is displayed. She leads students on an exploration of the galaxy, describing its halo and disk, as well as the location of our sun.
“Our galaxy is a cannibal,” De Mello announces, explaining that the Milky Way is gradually swallowing the nearby Sagittarius Dwarf galaxy.
Then she gives students something else to consider: “Five billion years from now, our galaxy will collide with the Andromeda galaxy.” Later she tells students, “Astronomy is the science of catastrophes.”
Throughout the semester, De Mello holds students’ attention with her passion for astronomy and interactive exercises. She passes around “space rocks,” coin-sized pieces of meteorite found in Argentina, Brazil, Arizona and China. Starburst candy and Milky Way bars are given out for Halloween, and — just days before the Vatican convenes a conference on the question of life on other planets — she dons an alien mask and encourages students to consider the origins and evolution of life in the universe and the possibility of life beyond the Earth.
Students also get hands-on experience being astronomers when De Mello assigns them to participate in the Galaxy Zoo project, an Internet-based galactic census that is using volunteers to classify a million galaxies by their shape.
She devotes one meeting of the course to what she calls “The Day of Why.” Dressed in black and sporting a necklace pendant imprinted with the image of a star, she invites students to ask questions that begin with the word “why.”
“Why is Pluto no longer a planet?” a student asks. Because of its small size, Pluto was reclassified a dwarf planet, De Mello explains.
“Why aren’t we sucked into the black hole at the center of the Milky Way?” another student asks. The black hole’s gravity does not pull in objects that are far away, the professor explains. “A black hole is not a vacuum cleaner. It will only pull objects that are really close to it.”
“Why did you become an astronomer?” asks McCarthy, a politics major from Keansburg, N.J.
“When I was 12 or 13 years old,” De Mello responds, “I became fascinated with space missions. I did not learn enough about space in high school. I decided I would become an astronomer so I could learn more.”
An extragalactic astronomer, De Mello studies objects beyond the Milky Way, including galaxies that are some eight billion light-years from Earth. Specializing in the evolution of galaxies, she is a research associate at NASA’s Goddard Space Flight Center in Greenbelt, Md., as part of the ongoing collaboration between NASA and CUA’s Institute for Astrophysics and Computational Sciences.
In 2008, De Mello made news by using NASA’s Hubble Space Telescope to identify “blue blobs,” clusters of mostly young stars 12 million light-years away. NASA has awarded her research grants of more than $300,000 over the past few years.
She is committed to public outreach, as well, especially to teens. For two years, she blogged about discoveries in astronomy for the popular Brazilian science magazine Superinteressante. Her book Living With Stars was written to inspire teens — especially young women — to consider careers in science. It was published in Brazil last year.
“What really motivates me to do astronomy is to learn about things and to discover things,” she says. “But if you don’t pass this to anybody else, it’s a waste.”
De Mello’s ability to teach nonscience majors seems effortless. But she says this introductory astronomy class, which she has taught twice, is difficult because of the need to take complicated scientific detail and break it into easy-to-understand terms.
To Katie Hoffman, a sophomore politics major from San Antonio, De Mello’s approach works. “I know that I will gain from this class because it was interesting,” says the student. “I suddenly began to learn things I never even thought were possible for me to learn.”
Late in the semester, De Mello hosts a class debate about space exploration, focused on a question being considered by NASA: Should humans explore Mars? With a show of hands, a majority of students says yes.
Then she poses a second, more challenging, question: Should we send astronauts to Mars without a guaranteed return to Earth, as some have suggested? The ethical issue is a deal-breaker for some students as they form teams to debate the economics, practicality and science of exploring Mars.
The debate ends with a show of hands on two more questions. Who would go to Mars if there were a guaranteed return to Earth? More than a dozen students raise their hands. And who would go if it were only a one-way ticket? Eight potential space pioneers raise their hands.
De Mello was more interested in the critical-thinking skills displayed by students than what position they took in the debate. “This is a science class in the sense that you have to think of the consequences and you have to justify things,” she explains.
By the end of the course, she says, students should “know our space in the universe — where our planet is, the environment of our planet, the environment of our galaxy.”
That lesson is not lost on McCarthy. “My generation has lost the ability to look into the sky with wonder and awe,” he says. “Dr. De Mello constantly pushes her students to appreciate the galaxy and universe around us and understand our place in it all.”