I don’t like to direct quote too much, but. . .
(From the caption)

“ Explanation:
When passing Earth on your way to Jupiter, what should you look for?

That question arose for the
robotic Galileo spacecraft
that soundlessly coasted past the Solar System’s
most photographed orb almost two decades ago.

The Galileo spacecraft, although originally
launched
from Earth, coasted past its home world twice in an effort to
gain speed
and shorten the duration of its trip to
Jupiter.

During Galileo’s first Earth flyby in late 1990, it made a majestically silent
home movie of our big blue marble rotating by
taking images
almost every minute during a 25-hour period”

Link to the page, full caption, and animation (quicktime vid.)
http://antwrp.gsfc.nasa.gov/apod/ap070514.html