Chabot College - Astronomy Worksheet- Scott Hildreth

Moon phases around the world

Soon as the evening shades prevail,
The moon takes up the wondrous tale,
And nightly to the listening earth
Repeats the story of her birth.
- Joseph Addison

Most people who have not taken as astronomy course believe that the moon appears in a different phase at different places on Earth (on the same day) - for example, that when the moon is full in the San Francisco Bay Area, it might be in the first quarter phase in Hawaii, or maybe a crescent over Japan.  This is wrong -

In this homework you'll explore this question, and more. Please turn in your results, typed and spellchecked, on paper in class or post your results in the Blackboard if you are absent.

1.  (Investigation) What does the Moon look like in Timbuktu when it is full in Hayward?  

Contact a friend or family member this week who lives somewhere else in the US, or even better, the world!  (Please choose someone who lives far away - at least 500 miles.  Los Angeles is OK, but San Jose is not!)  Ask them to go outside and view the moon, and to tell you what the moon looks like.  In particular, ask them what (local) time it is when they viewed the moon, and whjch side (left or right) is lit, and which is dark. Note that the moon this week will rise after sunset and before midnight, and it should be visible everywhere (weather permitting) in the early morning hours before sunrise.

IF you don't know anyone who lives far away, you have a bit more work to do - use the web to find a lunar phase table or newspaper for this week in a city outside of the US, or go to the library and find a paper from another city or country and search for the local moon phase on that day.  Compare what people there should see, and when, to what we can see.

Record in your response who you talked with, where they were, and what they saw.  Did they see the same shaped moon as you?  Could you see the moon at the same moment?  Where they surprised when you shared that the moon was the SAME shape for you?  How did YOU explain why the Moon is the same phase no mater where you are on Earth?  (And if you don't understand why this is, think carefully about how long it takes the moon to change its phases and how long it takes the Earth to spin!)  Aim for a paragraph on this question.

2. Additional Extra Credit

For extra credit, please locate an article or two on the subject of "The Moon Illusion", and evaluate it as to its scientific credibility as best you can.  Be sure to include all proper citation information, including author, date, title, publishing institution, and URL if found online. Look at Chabot College's website on citing online resources, available at:

And even more Extra Credit:

Re-read the section in chapter 2 on Eclipses. Then, research the Solar and Lunar Eclipses that will occur this year. Consider using the excellent website by Fred Espanak, at . Note specifically:


1/11 - SH

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