Geometry
Chapter 12, Astronomy and Geometric Models
Geometry can be used to find out about celestial bodies other than the earth. Even though a human has never actually set foot on Mars, there are many existing pictures of the planet's surface. Features on Mars are identified using a latitude and longitude grid like that on Earth. In this lesson, you will use longitude and latitude markings on Mars to figure out distances on the planet. You will also think about which units of measurement are best to measure which types of distances.
Part B, Longitude and Latitude
1. Go to the Martian Hemisphere Web site to see four separate views of Mars
projected into "point perspective." What does "point
perspective" mean in these images?
a. For this exercise, you will concentrate on the Schiaparelli and Syrtis Major mosaics. What are the latitude and longitude of the center of each of these images?
b. What are the latitude and longitude limits of each of these mosaics?
c. Which of these mosaics covers a greater surface area of the planet? How many degrees of longitude along Mars' equator does this image cover?
d. Go to the Mars Web site to find information which will allow you to find the circumference of Mars at the equator. Calculate this value to the nearest kilometer.
e. How many kilometers along Mars' equator does the Schiaparelli image cover?
f. Assuming that both the Schiaparelli and Syrtis Major mosaics are centered on the equator, what is the distance in kilometers between the centers of these images?
Part C, Measurement in Astronomy
2. Return to the Mars Web site to answer the following question.
a. Find out approximately how far Mars is from the Sun in both kilometers and astronomical units (A.U.).
b. According to your textbook, a light-year is approximately 9.5 trillion kilometers. What is the distance between the Sun and Mars in light-years?
c. Which of these three units is the best for measuring the distance between the Sun and Mars?
3. Mars has two moons, or satellites.
a. Find the names of these two moons and their circumferences at their equators in kilometers.
b. What are their circumferences in astronomic units? (According to your text,)
c. In general, when is it most appropriate to use kilometers? Astronomical units? Light-years?