You’re lecturing to your introductory college astronomy
class about Newton’s law of gravitation. You’ve carefully ex-
plained that the gravitational force depends on the product
of the two masses involved and on the inverse square of the
distance between them. You’ve shown a few examples or per-
haps videos and animations to help your students connect
the abstraction of an equation to the real physical world. You
may assign thoughtful homework problems, and you encour-
age the students to ask questions if they don’t understand, ei-
ther in class or during your office hours. You’re known as a
good lecturer, and your students always rate you highly at
the end of the term. Yet when you give your exam, you’re dis-
mayed to see how many of them can’t answer straightfor-
ward questions of the type you covered in class and assigned
as homework. So why does the same thing happen to instruc-
tors all over the country?
Astronomy-education researchers have been working to
solve that problem and many others facing instructors of as-
tronomy survey courses for nonscience majors. Such courses
are commonly called Astro 101. During a series of investiga-
tions conducted at the University of Arizona, education re-
searchers have developed conceptual questions used to assess
students’ understanding of core topics in such courses. Two of
the questions are “At what location between the Earth and
Moon does the net gravitational force on a spaceship become
zero as it travels between the two bodies?” and “Would a wax-
ing gibbous Moon ever be above the horizon during daytime?”
After traditional lecture-based instruction, one student
(Jennifer) stated in response to the gravity question, “halfway,
because exactly halfway causes the Moon’s and Earth’s gravi-
tational pulls to cancel out.” In response to the lunar-phase
question, another student (George) answered, “No, because
this phase only occurs when the Sun illuminates it during our
nighttime.” Those responses indicate that after instruction Jen-
nifer and George still had conceptual and reasoning difficulties
common among their peers prior to instruction.1
By the second time Jennifer and George answered those
questions, they had both participated in an interactive learn-
ing activity designed to help Astro 101 students confront
common misconceptions. After completing the activity on
gravity, Jennifer correctly answered, “Closer to the Moon
than to Earth, because Earth has a greater force on the space-
ship than the Moon does. But when the spaceship is closer to
the Moon, Earth loses some force while the Moon gains some,
until their strengths become equal.” And George was now
able to correctly reason that “this phase is highest in the sky
at 9 PM, therefore rising 6 hours earlier at 3 PM and setting
at 3 AM. So yes, it would be visible for some short time be-
tween 3 PM and 6 PM in the daytime.”
Improving scientific literacy
Research on the teaching and learning of Astro 101 has an im-
portant role to play in improving our nation’s understanding
of the scientific process and of the role science plays in soci-
ety.2 Last year, NSF reported that according to its Science and
Engineering Indicators, only about 25% of the country’s adults
were scientifically literate. Astro 101 courses reach nearly
250 000 college students each year. An astonishing 10% of all
US college students take a survey astronomy course, which
makes Astro 101 one of the most popular introductory sci-
ence courses.3 For many of those students, Astro 101 will be
the final science course they take for the rest of their lives.
The quality of their astronomy education may therefore have
a lasting impact on their scientific literacy and their attitudes
toward science.
The overwhelming majority of students taking Astro 101
are nonscience majors. They represent our society’s future
business leaders, lawyers, journalists, politicians, historians,
and—most critically—schoolteachers. As many as 40% of stu-
dents taking introductory science courses say that they in-
tend to become licensed teachers.4 Schoolteachers play a crit-
ical role in inspiring and training the next generation of
students to join the STEM disciplines: science, technology, en-
gineering, and mathematics. Improving the scientific knowl-
edge, attitude toward science, and teaching skills of prospec-
tive teachers must be critical goals for Astro 101 courses.
Unfortunately, middle- and high-school teachers often
emerge from college unprepared to teach their students
about astronomy and space science. With so much at stake,
it is clearly in our nation’s best interests to improve the teach-
ing and learning of Astro 101.
Over the past 10 years, astronomy-education researchers
have made significant gains in their understanding of how
students learn the subject. Much of that work has intentionally
©
2009 American Institute of Physics, S-0031-9228-0910-030-3 October 2009 Physics Today 41
Teaching and
learning astronomy
in the 21st century
Edward E. Prather, Alexander L. Rudolph, and Gina Brissenden
Edward Prather is executive director of the Center for Astronomy Education (CAE) at the University of Arizona’s Steward Observatory in
Tucson. Alexander Rudolph is a professor of physics at California State Polytechnic University in Pomona. Gina Brissenden is program
director of CAE.
A national study of teaching and learning in courses that introduce astronomy to nonscience majors
shows that interactive learning strategies can significantly improve student understanding of core
concepts in astrophysics.