Solar System Lab

What is the time between retrograde periods for Uranus? (The time between retrograde periods is the same as the time between successive oppositions and is known as the synodic period.)

12 months

Retrograde motion occurs when Earth passes an outer planet in its orbit around the Sun. The frequency of the retrograde motion is different for each planet. What is the time between retrograde periods for Jupiter? (The time between retrograde periods is the same as the time between successive oppositions and is known as the synodic period.)

13 months

There are two named bright stars located closest to Jupiter on the screen. Jupiter is forming a triangle with these two stars. What are the names of the two stars?

Betelgeuse and Aldebaran

Use the "right bracket" key (]) to move forward one week at a time for several months. Watch the motion of Uranus relative to the nearby stars as you move forward in time. (In this view, east is down and to the left.) When does Uranus first go through retrograde motion?

July through December 2013

Press the "right bracket" (]) key to move forward one week at a time. Watch the motion of Jupiter relative to the nearby stars as you move from June 1, 2103, to November 2, 2013. (You may wish to back up and observe more than once.) Which statement below accurately describes the motion of Jupiter that you observed?

Jupiter moves slowly eastward coming to a stop closest to Pollux.

Continue to move forward one week at a time ("right bracket" key). Watch the motion of Jupiter relative to the nearby stars as you move from November 2, 2103, to March 22, 2014. Which statement below accurately describes the motion you observed of Jupiter in this time frame?

Jupiter moves slowly westward stopping near Alhena.

You observe four planets orbiting the Sun. Planet A has retrograde periods that are 18 months apart. Planet B has retrogrades every 13 months. Planet C has retrogrades every 12 months. Planet D has retrogrades every 12 months also. Which planet is closest to Earth?

Planet A

The slower a planet moves in its orbit, the closer together its retrograde periods will be. How does the speed of a planet in its orbit relate to that planet's average distance from the Sun?

The slower the planet moves, the farther away it is from the Sun.

Retrograde motion occurs when Earth passes an outer planet in its orbit around the Sun. Jupiter's retrograde period happens less frequently than Uranus's. What can you deduce about their relative orbital speeds?

Uranus is moving slower because its retrograde periods are closer together.

Continue to move forward from March 22, 2014 one week at a time ("right bracket" key). When is the next time Jupiter undergoes retrograde motion?

from December 2014 to April 2015