Jupiter Definition and 157 Threads

This was a bonus question on my astronomy homework, but my knowledge of basic physics is so incredibly limited that I am really struggling with it. It's bugging me because I'd just really like to know how this works. "Given that Jupiter has no solid surface, how could you weigh yourself on...

http://www.space.com/scienceastronomy/jupiter_dark_spot_031023.html

21 new satellites of Jupiter have been found this year. Many are thought to be due to an ancient collision of a larger moon with a comet. Jupiter has four large moons and dozens of smaller ones (there are 60 satellites known so far). Galileo first discovered the four largest moons of...

http://www.jpl.nasa.gov/galileo/countdown/impact.html

http://news.bbc.co.uk/2/hi/science/nature/3109892.stm

egad! http://www.cnn.com/2003/TECH/space/04/05/jupiter.moons.ap/index.html

Has anyone else heard about this? http://science.nasa.gov/headlines/y2003/12mar_darkspot.htm?list827141