Name: ______Date: ______Period: ______

Calculating the Eccentricity of the Orbit of a Planet

Directions: Solve the following problems using your knowledge of Earth Science and a calculator. Be sure to show all work (put your measurements in the appropriate places in the eccentricity formula and calculate your answer).

  1. What is the approximate eccentricity of the ellipse shown below? Round your answer to the nearest tenths place.
  1. What is the approximate eccentricity of the ellipse shown below?

Base your answers to the following questions on your knowledge of Earth science, the Earth Science Reference Tables, and the diagram below. The diagram represents four planets, A, B, C, and D, traveling in elliptical orbits around a star. The center of the star and letter f represent the foci for the orbit of planet A. Points 1 through 4 are locations on the orbit of planet A.

  1. What is the eccentricity of planet A’s orbit around its star? Your answer must be rounded to the thousandths place
  1. List the planets from shortest period of revolution to longest?
  1. If planets A, B, C, and D have the same mass and are located at the positions shown in the diagram, the planet that has the greatest gravitational attraction to the star is
  1. Describe what will happen to the planet A’s orbital velocity as it travels from position 1 to position 3.
  1. On the diagram above place an X on planet D’s orbit where the orbital velocity is slowest and the gravitational attraction between the star and the planet is weakest.
  1. What is the astronomical term for the planet in this position?
  1. At what location in planet A’s orbit would the sun appear to be largest? What location would it appear to be smallest?
  1. When the distance between the foci of an ellipse is increased, the eccentricity of the ellipse will
  1. Increase
  2. Decrease
  3. Remain the Same
  1. What shape would the orbit of a planet with an eccentricity of 1 be?
  1. What shape would the orbit of a planet be if it had an eccentricity of 0?
  1. Using your answer to question 12, do any planets in our solar system have an orbit this shape?
  1. Is there any pattern in the eccentricity of a planet’s orbit in our solar system and its distance from the sun?

Base your answers to questions 16 and 17 using your knowledge of Earth science, the Earth Science Reference Tables, and the diagram below.

  1. What is the eccentricity of the planet shown in the diagram? Your answer must be rounded to the thousandths place.
  1. Which graph correctly shows the gravitational attraction of the star on the planet as it orbits the star?

The diagram below is a constructed ellipse. F1and F2are the foci of the ellipse.

  1. The eccentricity of this constructed ellipse is closest to the eccentricity of the orbit of which planet?

1