K-6 Activities - Dudley Observatory

Objective
K–6 Activities • B–70 •
Studying Early Astronomers,
Activity 6-1
The student should be able to compare and discuss the work of Ptolemy, Copernicus,
Galileo, Brahe, and Kepler.
Background
Refer to background information from Activity 5-1.
Tycho Brahe made careful observations of the sky for twenty-seven years. He kept
accurate nightly records of the positions of the planets that could be seen with the
naked eye — Mercury, Venus, Mars, Jupiter, and Saturn. Brahe mapped the positions
of about a thousand stars. Even though he believed that the sun revolves around
the earth and that the other planets revolve around the sun, the accurate data he
obtained was later useful to many astronomers. It was especially useful to Brahe’s
assistant, Johannes Kepler.
Johannes Kepler became an assistant to Brahe only a year and a half before Brahe
died. Through study of the thousands of pages of notes Brahe left, Kepler discovered
patterns and relationships. His discoveries are called Kepler’s laws. They give the
mathematical explanation for calculating:
1. The shape of a planet’s orbit.
2. The speed of a planet at each part of its orbit.
3. The period of revolution of each planet.
Procedure
• Conduct a class discussion in the planetarium or classroom covering each of the
astronomers covered.
• Assign written reports. Have students write news articles, in the present tense,
about the findings of these astronomers.
Extension Activity
Students could role play and dress according to the times.