On November 30, 2000, the Cassini spacecraft was travelling
toward Jupiter at a speed of 44200 km/hr, was 29.6 million km
away from Jupiter and 577 million km away from Earth.  (You can
check http://www.jpl.nasa.gov/cassini/english/ to get continuously
updated information on Cassini's status and whereabouts.)

(a) At about 3:03 PM Eastern Standard Time on December 30, 2000, 
the Cassini spacecraft made its closest approach to Jupiter.
About how far away will it be from Jupiter's center?  You will find
http://www.jpl.nasa.gov/jupiterflyby/ and its "FAQs" link useful.
What will be the gravitational acceleration from Jupiter on Cassini 
at that moment?

(b) All of Jupiter's visible light comes from reflected sunlight.
Jupiter reflects 50% of the visible light that strikes its cloudtops.
If the Sun's luminosity in visible light is 10^26 watts, what is
Jupiter's luminosity in visible light?  You will need to know the
distance between Jupiter and the Sun, and the area of the part of
Jupiter that faces the Sun at any given time.

(c) At its closest approach to Jupiter, what will be the flux of
visible light from the planet that strikes the Cassini spacecraft?