Advisory on the College Astronomy Curriculum: Implementing Adequacy and Integrating Observation

Wes Stone

Astronomy classes in college are often the choice of those students who do not wish to take science courses. Students view introductory Astronomy classes as less rigorous than comparable courses in the "mainstream" disciplines of Physics, Chemistry, and Biology, and therefore an easier way to fulfill that obnoxious Natural Sciences requirement. Another attraction of Astronomy is the sheer reach and exotic nature of the material. While other sciences may appear to be inexorably bound to the known world (and thus boring), Astronomy leaps this barrier by name alone. The very term conjures up visions of planets, stars, galaxies, black holes, and space flight. Even those who confuse Astronomy with astrology are entranced by the idea of the cosmos as it affects their lives.

Given this wealth of interest, Astronomy would appear to be a useful tool to spark the scientific imaginations of students at all educational levels. Regrettably, little attention or respect is paid to Astronomy in the science curricula of most elementary and secondary schools. In elementary schools, this is due mostly to a lack of astronomical knowledge among teachers and a system that does not promote the teaching of "non-traditional" subjects. (The computer seems to be changing this unfortunate and rigid outlook as I write this.) In the secondary schools, the issue is money. An Astronomy course would probably require the hiring of a new instructor and the allotment of more classroom time. School budgets are already stretched, crime and dropout rates are high, and voters resist tax increases for education. Under such circumstances, it is difficult to implement a new curriculum.

While there is a paucity of Astronomy courses at these levels, most colleges offer at least one course in the subject. This is the best chance we have to get tomorrow's teachers and parents interested in science. Unfortunately, many students end the term more confused than enlightened. It is a kind of culture shock to be thrown into a world of dizzying numbers (and rather more mathematics than most students are prepared for or eager to work at). Strange new ideas present themselves, seemingly far away from any practical application. Many will find that relativity and red-shifts are discouragingly complex. What good is it to know how far away something is, if there is no possibility of visiting it? One answer, obvious to the amateur astronomer, is that one can visit these wondrous places on any clear night. In the race to measure radiation from the Big Bang and to map the large-scale structure of the universe, visual observation has been forgotten. The wonder that led such non-professionals as William Herschel and Charles Messier (who were excellent observers but lacked mathematical genius) to first gaze at the stars appears to have been trampled.

Even in an age of technological advances, much of our knowledge rests on the work of those men (and women, like Caroline Herschel) who kept their gaze pointed skyward. There is still a quest among amateurs to be the first to glimpse a supernova or nova, or to have their names associated forever with a comet. These activities are too time-consuming and haphazard to command professional attention, but when amateurs discover an object the entire scientific community pores over it. Yet it is not only these most dedicated amateurs who carry on the grand old tradition of astronomy. It is everyone who looks to the sky in wonder, all of those who decide that the central region of a star cluster looks like a banana or that a certain planetary nebula is peanut-shaped. After all, it is the thrill of discovery, not the gathering and interpretation of data, that moved most of us to become scientists. Many educators (even Astronomy professors), for one reason or another, neglect or underemphasize this fact. This is a shame, since a properly designed observing program would beautifully complement classroom lecture topics. The key is to get the right objects and topics in the right sequence. For many solar system objects (such as Saturn and the Moon, which leave no dissatisfied customers upon telescopic observation), it is best to give a classroom lecture before the observing. Such a lecture equips the students to understand what they see through the eyepiece. For other, less spectacular objects, an extensive lecture leads to unrealistic expectations and a maximum of disappointment at the eyepiece. Those completely new to observing expect something spectacular to jump out at them. When the object turns out to be faint, fuzzy, and most of all small, the Nintendo-age brain may turn off completely. The proper way to deal with these objects is to lecture beforehand on observing (dark adaptation, averted vision, the relative importance of transparency and seeing, etc.). With this background and preparation, the brighter nebulae, double stars, clusters, and galaxies become intriguing, and will provoke the basic scientific questions. Some of these may be answered or dealt with on the spot, and all of them should be covered in the next class section, while the observatory experience is still fresh in the students' minds. An observation of a double star like Albireo or Mizar is the perfect lead-in to the discussion of star systems, star colors, determination of star distances, etc. After the topic has been covered, the student should go back to the observatory and be able to see the object in a whole new light.

There is no defensible reason to teach an Astronomy class without a laboratory. Laboratory sessions offer students an introduction to scientific measurement and optical theory. Observing skills are also developed. As a course project integrating laboratory and lecture topics, each student should conduct a "tour of the universe" (c.f., The Five Minute Tour of the Universe) in which the student picks examples of several types of objects to report on. Expect the student to be able to locate the objects with a telescope or binoculars, and to draw them as they appear at various magnifications. From research sources, the student should learn the estimated distance of each object, and its apparent size. The student will compare the published size with the visual impression, and use the apparent size along with the distance to estimate the object's actual size. Lastly, the student should investigate any special role of the selected objects in our exploration of the universe. If a CCD camera set-up is available, the student may elect to image one or more objects for extra credit.

The above should be a surefire way to add to the challenge and interest of the basic Astronomy course. There are many obstacles, however, that make it difficult to integrate observation into Astronomy courses. Timing may be the most important, as our artificial schedules tend to conflict with the clockwork of the heavens. Astronomy courses that meet only in the mornings or afternoons leave class hours open only to solar and lunar observing (although Venus at favorable apparitions is an exciting target; see Twilight Viewing of Planets). If one sets aside one night a week as an observing lab, there is a good chance that clouds will prevent the session from taking place. Cloudy nights are good occasions for showing films such as Powers of Ten, or lecturing on optics. Too many cloudy sessions, however, will result in a deterioration of the course. Students will become less willing to invest the effort to see whether it is clear outside. Professors will be more likely to plow right into the next chapter without an introductory observing session as planned.

There are ways to cope with all of these problems. Observing sessions should be frequent and flexible. Because the sky changes, both morning and evening sessions are useful. Attendance at scheduled lab sections should be required, and attendance at elective sections should be rewarded with extra credit. The lecture curriculum should be flexible as well, to allow for schedule changes. While light pollution is a problem on most college campuses, it can also serve as an educational experience if the students watch a slide show on the topic. Even large professional observatories have problems with light pollution, despite the presence of cost-effective solutions. Again, education and experience are the keys to changing the way we look at the world. Besides, Astronomy is a subject that begs for a field trip. Many Field Biology classes schedule several excursions. One or two voyages to darker skies should not be much of a problem for an Astronomy class. In all of these, it is key that the lab component be regarded as essential to the course and the students' understanding of the material, and not just something that "we'll do if we have the time".

These are some preliminary suggestions for integrating observing into college Astronomy curricula. For the greatest effectiveness, incorporate as much hands-on work as possible. No student should leave the class without having used a telescope to locate and observe objects. Finally, teaching methods should be as individualized as possible. Some students will receive the observing better than the lectures, while the opposite will be true for others. Still others will bring in peripheral interests, such as optics or mythology. If all these interests are accommodated and brought into the discussion, the course will be a success.

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