Name: ________________________ | DUE 10/11 |
ID number: ________________________ |

Between January 7 Using these and other observations, Kepler tried to determine
if the Galilean Satellites obeyed his third law. The first part
of this assignment is to reproduce Kepler's calculation. To do
this you need to measure the semimajor axis To measure the semimajor axis Record your measurements below, and find
Is Kepler's third law obeyed? __________ |

The second part of this assignment is to use the generalized form
of Kepler's third law to estimate the mass of Jupiter. To do this,
you first need to pick *any* one of the satellites, and express
its semimajor axis *a* in AU and its period *P* in years.
Use the small-angle formula to find *a* in AU:

Given *a* and *P* in the right units, compute
*a*^{3} ÷ *P*^{2}, which is Jupiter's
mass in units of the Sun's mass. Do this calculation in the space
below. If you've done everything right, you should get a value of
about 0.001 -- Jupiter is only 0.1% as massive as the Sun.

Joshua E. Barnes (barnes@ifa.hawaii.edu) Last modified: October 5, 1999