This activity will require approximately three 30-minute classes
205-8: identify and use a variety of sources and technologies to gather pertinent information (e.g., use electronic and print resources or visit a planetarium to gather information on the visual characteristics of planets)
206-2: compile and display data, by hand or by computer, in a variety of formats including frequency tallies, tables, and bar graphs (e.g., prepare a diagram showing the orbits of the planets)
206-5: draw a conclusion, based on evidence gathered through research and observation, that answers an initial question (e.g., conclude that simulated flour craters are deeper and wider when the marble is heavier or is dropped from greater heights)
Work in groups of two using the Tracking Sunspots applet to determine the axial rotation rate of the Sun. Learn that the surface of the Sun is not solid, but rather a turbulent mix of gas, thus exhibiting differential rotation (some parts of the Sun rotate faster than others). Learn of the connection between sunspots and Northern Lights.


In this activity students will be using the Tracking Sunspots applet to investigate sunspots and the movement of the sunspots across the surface of the sun. Student will use the functionality of the applet to determine both linear and angular approximations to the rotation of the Sun. Through their investigations, students should be able to identify differential rotation. Students will also use the applet to determine the size of the penumbra and umbra of sunspots.

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Before commencing this lesson, teachers should become very familiar with the applet to ensure that they will be able to assist the students should the need arise.
The lesson should begin by briefly introducing students to sunspots
Students should be made aware that Galileo was the first person to discover sunspots in 1610
The teacher should also explain that sunspots occur on the surface of the Sun and can therefore be used to determine the rotation rate of the Sun
After briefly introducing the concept of sunspots, the teacher should then explain that in this activity students will be using an interactive applet to observe and track sunspots on the solar surface through which students will determine the rotation rate of the Sun
The teacher should monitor students progress with the applet and be prepare to assist when students are having difficulties
Once students have had sufficient time to work with the applet, the teacher should reassemble the class and begin the closure discussions

Reassemble the students and initiate a discussion as to the findings the students were able to interpret from their work with the applet. The teacher should then lead a discussion based on the following questions. Were all students able to detect differential rotation? Did students obtain significantly different results between linear and angular calculations? What was the largest sunspot the students identified?

Rubric template