Wondering About Gravity

Sometimes when I don't take time to think about something, the conclusion is usually faulty.  I know that I am not alone on this.  I was wondering where I would weigh the most if I used the same spring scale but got weighed in different locations.  So, don't take time to think about this but tell me, where do you think you would weigh less, in Death Valley or on top of Mount Everest?

My quick answer without thinking was Death Valley because I would be closer to the center of the Earth, as if the center of the Earth is where gravity comes from.  Well, after thinking about it, I changed my mind and now think it would be on top of Mount Everest.  Why, because there is more mass below me up on the mountain than there would be down in Death Valley.  Mass is (or particles are) what posses the attracting force we call gravity, so anywhere there is more mass under you, you would weigh more on a spring scale.

The same is true for the moon.  In my latest copy of Discover, there was an article in it that told about two moon orbiters that have sent back information about gravity on the moon.  The warmer colors, like reds, are the highest and the darker the lowest.  Well, they say a picture is worth a thousand words, so I am going to post a picture to keep my hands from getting too tired trying to type a thousands more words:

OK, I think I made it large enough to read what it says, if not, click on the picture to download it or enlarge the blog page.  Now you all have a great out of this world day, you hear?