Why teach astronomy? Astronomy is deeply rooted in the history of almost every society, as a result of its practical applications, and its philosophical implications. It still has everyday applications to timekeeping, seasons, navigation, and climate, and long-term applications to climate change and biological extinctions. It not only contributes to the advancement of physics and the other sciences, but it is an exciting and rapidly-changing science in its own right. It deals with the origin of stars, planets, and life itself. It shows our place in time and space, and our kinship with other peoples and species on Earth. It reveals a universe which is vast, varied, and beautiful, and promotes curiosity, imagination, and a sense of shared exploration and discovery. It provides an enjoyable hobby for millions of people. In the classroom, it can demonstrate an alternative approach to the "scientific method" - the observational/theoretical approach. It can attract young people to the sciences, and promote public interest and awareness in science - important considerations in an age when science is so important to our economy and our everyday life.

In timetabling the astronomy unit, keep in mind the weather, the visibility of the moon and other objects such as planets, or other related special events. There is some merit to spreading astronomy out over the whole school year. Around Toronto, early fall and early spring are reasonably clear, and it gets dark early. Winter is reasonably clear, but cold. The winter sky is especially attractive.

CURRICULUM

Education is a provincial responsibility in Canada, so the science curriculum - and the place of astronomy in it - varies from province to province. Generally, students are introduced to motions of the Earth, sun and moon (day and night, seasons, moon phases and eclipses), and perhaps to some more interesting topics such as planets, stars and galaxies.

In the US, the National Science Foundation has an education budget of over half a billion dollars a year, and some of this has been used for projects to develop curriculum, activities and materials for the teaching of astronomy. There is no equivalent source of funds in Canada, so we should make use of the US developments wherever we can.

Project STAR (Science Teaching through its Astronomical Roots) was completed in 1992 with the publication of the Project STAR text, which is the culmination of six years of research into the astronomy misconceptions of students, and development of hands-on activities to address these.

Textbook and teachers' manual. Kendall/Hunt Publishing Company, 4050 Westmark Drive, Dubuque IA 52004.

Activity materials. Learning Technologies Inc., 59 Walden Street, Cambridge MA 02140.

"A Private Universe" video. Pyramid Film and Video, Box 1048, Santa Monica CA 90406

The Project STAR approach can be adapted to elementary and secondary school, or introductory college courses for non-science students.

An important by-product of Project STAR was Project SPICA (Support Program for Instructional Competency in Astronomy), which produced a cadre of teachers trained in the STAR approach, and also produced the Project SPICA handbook listed at the end of this document.

Among the results (re)discovered by Project STAR:

1. the topics which are taught must be matched to the students' level of cognitive development
2. students (and adults) hold deep-seated misconceptions about physical and astronomical topics, which must be identified and dealt with in the course of teaching
3. inquiry-based teaching, with appropriate hands-on activities, and most appropriate for effective teaching and learning

Make sure that your students are aware of what can be seen in the night sky, even though "the stars come out at night, but the students don't". Teach them how to use a star chart. You can use the star charts in the various resource materials listed later (Globe and Mail, SkyNews .....).

To use a star chart, choose a chart for the correct latitude, date and time. The charts in this publication are suitable for latitudes in most of Canada. Hold the chart in front of you so that the direction which you are facing is down. The perimeter of the chart represents your horizon; the centre of the chart represents the point directly overhead. The dots on the chart represent the stars - the larger the dot, the brighter the star. [The stars, of course, are white on a black background!]

Learn how to use the star chart the way you would learn to use a road map. If you can recognize one constellation, you can then "hop" from that one to another.

Choose a "constellation of the week" or other sky object (such as a planet) of the week. You can then emphasize finding that object successfully. Ask the students if they have done so; if not, you find out what the problem is, and help them to succeed the next night!

Learn one or two constellations by heart. The Big Dipper and Orion are good starting points. Constellation myths may seem uncool, but they are something which the students absorb and remember. Each culture has its own constellations and myths, so there are opportunities to develop multicultural perspectives here.

THE SOLAR SYSTEM

There are many misconceptions about the size and layout of the solar system. A scale model removes many misconceptions: scales include:

1. The earth is represented by a human head, about 25 cm in diameter; in this case, the moon would be represented by a human fist, about 8 cm in diameter - but situated 8 m away! The sun would be a 25 m blimp, situated 2.5 km away! It is now possible to understand why there is not an eclipse of the sun and moon every month.
2. The sun is represented by a 46 cm beach ball; in this case, the earth would be represented by a 0.4 cm pea, situated 50 m away. Pluto would be represented by a grain of sand 2 km away, and the next nearest star would be another beach ball, situated on the other side of the earth, 13,300 km away! The distance between the stars now becomes apparent.

NIGHT AND DAY, THE SEASONS, AND THE PHASES OF THE MOON

These basic astronomical concepts are misunderstood by the majority of the population. In the course of Project STAR's research, it was determined the majority of Harvard graduates (and members of its Board of Regents) did not understand the cause of the seasons, the moon phases, and the fact that the earth revolves around the sun once a year.

The Project STAR textbook and activities are good on these points - or just use simple, hands-on models.

Two of the more popular misconceptions about the seasons are:

1. It is hottest in the summer because of the shape of the earth's orbit - we are closest to the sun in the summer.
2. It is hottest in the summer because of the tilt of the earth's axis - we are closest to the sun in the summer (this seems reasonable if you do not understand the scale of the sun-earth system).

These concepts are so basic that it is worth teaching them right, i.e. monitoring the students' preconceptions, and being absolutely sure that they understand the concepts, and can explain them from their understanding, and not just from their memorization.

THE SUN

The sun is conveniently visible during the day (usually), and is therefore available for activities.

1. Project an image of the sun on a sheet of white cardboard, using binoculars or a small telescope focussed on infinity. Observe sunspots, and watch the sun rotate from day to day. It requires a bit of practice to set up such a demonstration but, once you get the hang of it, it can be set up very fast. Practice ahead of time.
2. You can estimate the power of the sun by means of the inverse square law, by comparing its light with that from a bulb of known power, using a "null photometer". This is an excellent activity for a high school physics class. The inverse square law of brightness [which says that the apparent brightness B of a light source is directly proportional to the power P of the light source, and inversely proportional to the square of the distance of the light source D] is not often covered in physics courses - but should be. [Other physics concepts which can be taught with astronomy are: distance by parallax, distance by apparent size, distance by apparent brightness, relation between colour and temperature of a hot object, spectroscopy .....]
3. You may want to track the path of the sun in the sky, on each day or from one day to the next. This is done most safely by using the shadow of the sun.

NEVER OBSERVE THE SUN DIRECTLY, ESPECIALLY WITH BINOCULARS OR A TELESCOPE; PERMANENT EYE DAMAGE COULD RESULT.

THE EARTH

1. Develop an awareness of the earth as a planet.
2. Study photographs of the earth, from space.
3. Use a globe as a model of the earth; a first step in modelling the universe.
4. Think about life on the earth, and elsewhere.

THE MOON

1. Observe and record the moon: when it is, where it is, what shape it is, when it rises and sets. Don't forget that it is visible in the daytime.
2. Phases are easy to observe and record, but hard to explain (see comments above); use a three-dimensional explanation such as a hands-on model. The problem is that moon phases are a three-dimensional phenomenon which is usually explained in a two-dimensional way!
3. Make a moon calendar from your collective class observations. On any given day, where was the moon? What was its phase?
4. Observe the general appearance of the moon's surface, as seen with the unaided eye: "the person in the moon". You can also study photographs of the moon's surface.
5. Watch a film/video of one of the Apollo missions.
6. Eclipses: forget it unless there is actually going to be one. There will be lots of information in the media.

1. Observe them if they are visible, for sure!

   The planets are found in a band in the sky called the zodiac, which contains the constellations Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpius, Sagittarius, Capricornus, Aquarius and Pisces. The planets usually shine with a steady light, as opposed to the stars which tend to "twinkle". Mercury is as bright as the brighter stars, but is never more than 28 degrees from the sun. Venus is very bright, and is never more than 45 degrees from the sun. Mars is reddish, and can be as bright as the brighter stars. Jupiter is as bright as the brightest stars. Saturn is almost as bright as the brighter stars. Consult the planet tables in the resource materials listed, to find out where each planet is. If you are teaching planets in your classroom, you should make sure that the students look for them in the sky!

2. Use slides/films/videos to capture the excitement of planetary exploration; the Astronomical Society of the Pacific has good ones.
3. Activity: "Invent an Alien" (suited to a particular planetary environment, or an environment of your making) is a classic! The idea is to design an alien which is suited to a real or imaginary environment in the solar system or beyond: on one of the known planets or moons, or a hypothetical one elsewhere.

These are interesting topics, especially as it now appears that collisions between these objects and the earth may explain the extinctions of species such as dinosaurs. There is certainly an abundance of evidence (in the form of impact craters) for these collisions.

On the other hand, these are concepts with which students have very few firsthand experiences.

There is a classic demonstration of "Creating a Comet" (out of dry ice and sand) which is worth tracking down. It is in the Project SPICA, and Universe at your Fingertips books, listed at the end.

IS A TELESCOPE NECESSARY?

Binoculars and telescopes can be useful, but are not essential - much interesting astronomy can be done with the unaided eye. If binoculars are available, use them! The Project STAR materials include inexpensive small telescopes. You may be able to find a local amateur astronomer who would be happy to let your students look through his/her telescope.

RESOURCES

In addition to the reading material which follows, you may be able to make use of the following:

1. There is a list of planetariums, observatories and science centres in the Canadian Almanac and Directory. Take your students to visit one of these.
2. The largest organization of amateur astronomers in Canada is the Royal Astronomical Society of Canada. Their branches across Canada present a wide variety of activities which might be interesting to you and your students. A member of the RASC might be willing to visit your class, and demonstrate a telescope. The national office of the RASC is at 136 Dupont Street, Toronto. Ontario M5R 1V2.
3. The Globe and Mail publishes a monthly astronomy column from the National Museum of Science and Technology, around the first Saturday of every month. Other local newspapers have astronomy columns; the Toronto Star, for instance, has a column by Terence Dickinson every Sunday. Read these columns, and post them on your bulletin board!

Astro Adventures: An Activity-Based Astronomy Curriculum, by Dennis Schatz
   and D. Cooper.  Pacific Science Center, 200 2nd Ave. N., Seattle, WA
   98109-4895.
Astronomical Society of the Pacific, 390 Ashton Ave., San Francisco CA 94112.
   Excellent source of astronomical slides and other such material; send
   for their catalogue.  Also publish a free quarterly teachers' newsletter;
   to order it, write on your school letterlead.
Astronomy.  P.O. Box 1612, Waukesha WI 53187, USA.  A popular non-technical
   monthly magazine for general astronomy readers.
Astronomy Adventures (Ranger Rick's NatureScope).  National Wildlife Federation,
   1412 16th St. NW, Washington DC.  Excellent fun activities for younger
   children in schools or youth groups.
The Beginner's Observing Guide, by Leo Enright.  Royal Astronomical Society
   of Canada, 136 Dupont Street, Toronto, Ontario M5R 1V2.  A simple but serious
   introduction to the night sky.
Exploring the Night Sky, by Terence Dickinson.  Camden House Publishing, 1987.
   An award-winning guide, especially for young people.
NightWatch, by Terence Dickinson.  Camden House Publishing, 1989.  Excellent
   introduction to the night sky.
Observer's Handbook, edited by Roy L. Bishop.  Royal Astronomical Society
   of Canada, 136 Dupont Street, Toronto, Ontario M5R 1V2.  An annual guide
   to sky phenomena and other astronomical information; the best of its kind.
Project SPICA: A Teacher Resource to Enhance Astronomy Education, edited by
   N. Butcher Ball et al.  Kendall/Hunt Publishing Co. 1994.  An excellent
   compilatiopn of activity and resources for teaching grades 3-12.
Sky and Telescope.  P.O. Box 9111, Belmont MA 02178-9111. A popular monthly
   magazine for amateur astronomers.
Sky News.  P.O. Box 9724, Station T, Ottawa, Ontario K1G 5A3.  A publication
   of the National Museum of Science and Technology: general astronomy from
   a Canadian perspective.
The Universe at your Fingertips, edited by Andrew Fraknoi et al.  Astronomical
   Society of the Pacific, 390 Ashton Avenue, San Francisco CA 94112.  Another
   excellent collection of teaching activities and resources for grades 3-12.	

Return to the Astronomy Resources page.