1. as the distance between the foci increased, how did the shape of the ellipses you drew change 2
it became more eccentric
2. what is the correct name for the shape produced when the two foci are one point? ellipse
3. what is the eccentricity of an ellipse that has its 2 foci as one point?
4. the major axis of the earth's orbit is approximately 186,000,000 miles in length. the distance
between the sun and the imaginary second focus is approximately 3,000,000 miles. what is the
approximately eccentricity of the earth's orbit?
5. if the sun is at one focus of the earth's orbit, where is the second focus? (hint - see question #4)
6. which of the three ellipses that you drew, ellipse ab, ellipse cd, or ellipse ef most closely
resemble the earth's eccentricity? why did you choose that ellipse?
7. list two specific differences between an ellipse and a circle.
- oval shaped orbit
- 2 focal points
8. complete the chart below. (all distances are in aus). round off to three decimal places.
planet
distance between foci (au) major axis (au)
eccentricity
mercury
0.16
0.78
venus
0.00
1.44
earth
0.03
2.00
mars
0.28
3.04
jupiter
0.50
10.44
saturn
1.06
19.20
uranus
1.80
38.46
neptune
0.60
60.20
pluto
19.70
78.80
using the chart - answer the following:
1a. which two planets have the most circular orbits?
1b. what are their relative positions in the solar system?
2a. which two planets have the most eccentric orbits?
2b. what are their relative positions in the solar system?
3. list the planets in order from the most circular to the least circular.
4. how does the earth's orbit compare to all the other planets?
bonus: a new planet has been discovered with an aphelion of 35 au and a perihelion of 29 au.
calculate its eccentricity and explain what you did.