Reference no: EM131022656

Sunrise/Sunset Long -Term Project

I. Introduction

There are many events and motions in the sky which are not immediately apparent from a cursory glance. Long term observations reveal a lot about the motions of the planets (including the Earth), the Moon, and the Sun. This project will allow you to make long-term observations of the Sun and explain your observations based on a knowledge of basic modern Astronomy.

II. The Observations

1. Pick a location from which you can consistently observe either sunsets or sunrises for a long period of time (5-6 weeks). Note: You MUST make ALL of your observations from exactly the same location!! Also, choose a place that has a relatively flat horizon in the direction of sunrise/sunset that won't change. If you observe sunsets standing east of a multi-story building under construction, you will get inconsistent results.

2. Decide whether you will observe sunsets or sunrises for this project. You cannot switch in the middle of the lab. It must be one or the other. Remember, you will be doing this periodically for about six weeks.

3. During your first observation, make a careful sketch of the horizon in the direction of sunrise/sunset. Be sure to include landmarks and objects that will help you to locate the exact location of the sunrise/sunset on your horizon. Update this sketch with every subsequent observation, or make a new sketch. For sunsets, mark due West on your sketch. For sunrises, mark due East on your sketch.

Possible option: photographs of the sunset/sunrise show this very neatly.

4. Record the exact time, date, and location of sunrise/sunset every 3 to 4 days (this can be changed slightly to allow for bad weather) for 6 weeks. Sunset is defined as the moment when the last portion of the Sun moves below the horizon. Sunrise is defined as the moment when the first portion of the Sun moves above the horizon.

Use the techniques from the Altitude and Azimuth lab to measure the Azimuth the sun rises, or the Azimuth the sun sets. Use the data table on the next page to record the information from your observations.

5. Answer the questions following the data table. Referencing a basic astronomy text may be helpful.

Be sure to include your sketches or photographs when you turn in your project.

III. Data Tables

IV. Questions

1. What did you notice about the times of Sunrise/sunset during the project?

2. What did you notice about the locations of Sunrise/sunset?

3. Compare your times of sunset/sunrise to those in a local newspaper or astronomical website for your observation dates. Were they the same? Discuss why there can be differences between your observations and the paper's times.

4. Explain in detail the physical reasons for your answers to questions #1 & #2. Include at least one sketch of the Earth-Sun system as viewed from space in your discussion.