Here is a synopsis of the astronomy laboratory experiments. If you would like to retrieve a copy of the experiment in WordPerfect format for the PC, click on the {WP} indicator to retrieve and save the experiment. If you already have these experiments, you might like to watch the revision date, to get the latest version. This date is printed in the experiment on its last page. The revision date for this page is 13 January 2002.
This is the first experiment in the astronomy sequence. The purpose of it is to introduce the student to the appearance and motions of the objects in the sky, using Starry Night in the Windows environment. Basically, we want to show that the Earth and its rotation establishes Hipparchus' equatorial system, [800x600x256] and that the stars remain (mostly) fixed within it. By understanding the equatorial system the student can partition the sky, locate objects, prepare for the ecliptic and horizon systems, and get a feel for how the sky appears to rotate around the Earth. We can also begin to show the student where the constellations like Orion [800x600x256] are and to recognize their forms and their component stars.
This is the second experiment in the astronomy sequence. The purpose of it is to introduce the student to the correspondence between the ecliptic and the equatorial coordinate system via Starry Night in a Windows environment. We want to show that the location of the planets [800x600x256] and the movement of the Sun establishes the ecliptic. The student discovers that the start of the seasons corresponds to the location of the Sun [800x600x256] throughout the year. The student discovers the obliquity of the ecliptic. By traveling back to 1000 BC, the student also discovers precession, and answers the question raised in the first experiment regarding astrology and sun signs. By precessing back to 3000 BC, the student discovers that Thuban, in Draco (and not Polaris) was not the pole star [800x600x256].
This is the third experiment in the astronomy sequence. The purpose of it is to permit the student to discover that the appearance of the celestial objects thus far discussed is a function of time, date, and location on the Earth. In doing so, a student discovers the correspondence between the latitude of the observer and the altitude and visibility of stars [800x600x256] and the Sun. The "harvest Moon" phenomenon [800x600x256] and the astronomical circumstances [800x600x256] surrounding the sinking of the Titanic are explored.
There are also many Web sites concerning the Titanic:
This is the fourth experiment in the astronomy sequence. The purpose of it is to continue discovering the relationship between the ecliptic and horizon coordinate systems. The students rediscover why the Chinese year zero is our March 1953 BC. [800x600x256] They look at how the Hopi used a horizon calendar. [800x600x256] They rediscover that the length of the year is not exactly 365 days, and that the true Sun [800x600x256] cannot be used as a timekeeper. Any of these could be expanded into a semester-long (or year-long) project.
This is the fifth experiment in the astronomy sequence. The purpose of it is to permit the student to rediscover the eclipse seasons by seeing the Moon nearing the ecliptic at new Moon [800x600x256] phase. Students then search for the next several solar eclipses, to discover the ~ 6 month eclipse season interval. Additionally, students witness the famous total eclipse of 585 BC. [800x600x256]
You may wish to set this up for a forthcoming solar eclipse in your area. As the regression of the line of nodes of the lunar orbit moves the eclipse season earlier in the calendar year, you may also wish to reposition this experiment in the sequence of experiments.
This is the sixth experiment in the astronomy sequence. The purpose
of it is to permit the student to simulate a lunar eclipse, perhaps an
eclipse which can be observed locally. Ideally, it should be revised each
semester to simulate a forthcoming eclipse. The instructor describes
lunar eclipses, the circumstances [800x600x256], eclipse seasons, and the Saros. The
student can predict the circumstances of an eclipse, rediscover eclipse
seasons, and measure the period of the Saros.
This experiment, like the solar eclipse experiment, may need to move earlier in the sequence. It is a particularly valuable experience for students if they can directly observe a eclipse for which they have previously seen the computer demonstration.
This is the seventh experiment in the astronomy sequence. The purpose of it is to permit the student to discover that the motion of the Moon and the planets involves both their own motion and the motion of the Earth. Kepler needed to remove the motion of the Earth from the synodic periods in order to determine the sidereal periods. This experiment also allows the student to see how the Moon [800x600x256] and planets move about in the sky. This experiment also sets up for Kepler's Harmonic Law. It also allows something they cannot easily see - planets in conjunction with the Sun. [800x600x256] Note - this experiment should be set up for the day (or week) in which it will be taught.
This is the eighth experiment in the astronomy sequence. The purpose of it is to permit the student to rediscover how Kepler was able to triangulate the distance to Mars. This experiment, like the previous one, sets up for Kepler's Harmonic Law. It is important to explain Kepler's method [800x600x256] - after one sidereal period, Mars returns to the same point on its orbit, but the Earth does not, allowing the triangulation. The last page of the experiment in WP format shows a drawing [800x600x256] in which the symbols for the distances and angles are illustrated.
This is the ninth experiment in the astronomy sequence. The purpose of it is to permit the student to rediscover Kepler's harmonic law. In an earlier experiment, the student learned how to extract a planet's sidereal period from an observationally determined synodic period. In another experiment, the student learned how Kepler determined the distance to the planets by triangulation. This experiment synthesizes the two to allow the student to rediscover Kepler's Harmonic Law. Triangulation for the distance to all the other planets is long and dirty, so we use Distant Suns' off-Earth view mode [800x600x256] to get the semi-major axes.
This is the tenth experiment in the astronomy sequence. The purpose of it is to permit the student to rediscover, as Galileo did, the moons of Jupiter [640x480x256]. Further, students confirm that Jupiter's moons obey Kepler's Harmonic Law. This experiment sets up for Newton's modification of the law, which allows the determination of the masses of the planets. You may also wish to see The Galileo Project.
This is the eleventh experiment in the astronomy sequence. The purpose of it is to permit the student to measure the masses of Jupiter and Saturn by using Newton's modification of Kepler's harmonic law.
This is the twelfth experiment in the astronomy sequence. The purpose of it is to permit the student to rediscover, as Roemer did, that the "clock" of Io in its orbit around Jupiter varies in a 400-day cycle. The reason is that the synodic period of Jupiter is 400 days, and that when Jupiter is at opposition, the clock runs fast, whereas at conjunction, the clock runs slow. These effects are due to the light-travel time across the solar system. With great care, the student can determine the speed of light to within about 20%.
You might like to point out that all of this came about because navigators needed a clock in order to determine longitude. A look at a map of the "new world" [640x654x256] prior to the late 1700s will reveal this. (I like to have one in a .BMP or .GIF file for the students to see for themselves. Try the University of Georgia's archive of old map images.) Astronomers had suggested using the moons of Jupiter as a clock, but soon discovered a 400-day period error of ± 10 minutes.
