A human probe cannot land on
the surface of Jupiter. The swirling, turbulent atmosphere grades into
a gaseous surface, getting increasingly solid as the probe would
aimlessly fall into Jupiter. The solid portion of Jupiter is thought
to be in a melted state of metal, so the probe would disintegrate,
before any data could be obtained.
Jupiter radiates nearly twice as much heat as it
receives from the Sun. Satellites that formed nearer to the planet are
terrestrial like, similar to our Moon. Galileo discovered them in 1610
and hence they are sometimes referred to as the Galilean moons.
In addition to the Galilean moons, Jupiter has several smaller
satellites and rings.
Jupiter is almost a world into its own, with
just a little more helium and hydrogen it might have been its own