Galileo:
Liked the famed astronomer for which it was named, Galileo
spacecraft logged quite a few firsts during its 14-year
mission to
Jupiter. Among its discoveries: an intense radiation belt
above Jupiter's cloud tops, helium in about the same concentration as
the sun, extensive and rapid resurfacing of the moon
Io because of
volcanism, and evidence for liquid water oceans under the moon
Europa's icy
surface.
The orbiter carried a small probe that became the first to sample the
atmosphere of a gas planet. The probe measured temperature, pressure,
chemical composition, cloud characteristics, sunlight and energy
internal to the planet, and lightning. During its 58-minute life, the probe
penetrated 200 km (124 miles) into Jupiter's violent atmosphere before it was
crushed, melted, and/or vaporized by the pressure and temperature of the
atmosphere.
Galileo was deliberately crashed into Jupiter in September 2003 to avoid
an accidental collision with - and possible contamination of - one of Jupiter's moons.
Read More About Galileo
Visit the Galileo Website