College of San Mateo Exploring the Planets Using Stellarium Questions

Today, you are going to use Stellarium, a free planetarium program, to investigate what the sky looks like on different planets.

PROCEDURE:

Go to the web and type stellarium.org and download the program. It works on Macs and PCs. Once you do that, go to the lower left of the program and you will see a number of panels. Go to the top one, which is the Location window (F6). Click on it and find San Mateo and click on it. You are now in San Mateo. Below the Location window, is the Date/time window (F5). Click on it and a window will appear to the right. The leftmost part of the window is the month, day, and year. The rightmost part is the time in 24 hour time. At the bottom left of the screen, you will see icons for constellation lines, stars, and the planets. Click on them to show them in the sky. Try to keep the FOV (field of view) to ~ 89 degrees or so.

Set Stellarium for today s date, April 22 at 7 hr 0 min 0 sec. Face East (E) and notice that the Sun is just above the horizon. We are now going to visit 5 planets to see how a long a day is on them. Go again to the Location window. At the bottom right of this window, you will Planet. Right now it is on Earth, since we set the location to San Mateo. Scroll through until you find Mars and close this window. You will see that the time is 14 hr 0 min 0 sec. Now, face East (E). Scroll through the hour in the Time window until the Sun just appears above the horizon. The hour will be around 22 hr. Now, increase the time until the Sun appears again at the same place on the horizon. How many hours have passed? That number of hours is a day on Mars.

Mars

1. a) Time Sun is above horizon _________hr

b) Next time Sun is above horizon _________hr

c) Difference in time = Length of a Martian day_________hr

Once done with Mars, go to Jupiter, Saturn, Uranus, and Neptune and repeat the procedure.

Jupiter

2. a) Time Sun is above horizon _________hr

b) Next time Sun is above horizon _________hr

c) Difference in time = Length of a Jovan day_________hr

Saturn

3. a) Time Sun is above horizon _________hr

b) Next time Sun is above horizon _________hr

c) Difference in time = Length of a Saturnian day_________hr

Uranus

4. a) Time Sun is above horizon _________hr

b) Next time Sun is above horizon _________hr

c) Difference in time = Length of a Uranian day_________hr

Neptune

5. a) Time Sun is above horizon _________hr

b) Next time Sun is above horizon _________hr

c) Difference in time = Length of a Neptunian day_________hr

Investigating Saturn

6. a) Go to the Location window and set it to Saturn and face South (S). You are now at the same latitude on Saturn as you were in San Mateo. Set the date to today s date, April 22 and set the time to sunset by setting the hours to 11 hr 0 min 0 sec. Notice Saturn s rings! Keeping the Location window open, click on the latitude of 37^o and scroll it upwards about 10^o above 37^o and downward about 10^o below 37^o. What did you notice happened to the rings as you changed your latitude? (a few sentences)

b) Return the latitude to 37^o close the Location window and face South. Make sure that the time is set for 11 hr 0 min 0 sec, which will be around sunset. Change the time slowly from 11 to 15 hr and notice and explain what happens with Saturn s shadow.

6 c) Set the time back to 12 hr. You should now see a number of Saturn s moons. What moons do you see? You can tell that they are moons since they will have names that are not constellations and each moon will be followed by (SII, SVI), etc.

7. Lastly, set the time to 20 hr and face West. The Sun should be above the horizon. Find the Search window (F3), (the 4^th icon from the top on the left side of the program). Type Earth and click on it. The program will now center Earth on your screen, but, since it is still daylight, you won t see anything. Now, zoom inward and what do you see? (a few sentences).

What phase is the Earth?

What have you learned in this lab?