now a spacecraft that's far away really doesn't have the ability to measure much
besides the overall mass of the planet.
It can't tell any deviations from this non-vehicle major.
As the spacecraft has an orbit that's potentially closer in.
It might feel the difference between something at the poll and something at
the equator and start to measure the first order effect of this elongation like this.
Even closer in you have the chance of measuring even more subtle variations.
In real life it's not going to be that there's dense material here and
everything else is exactly the same.
There's going to be increasingly dense hydrogen compressed in through here.
Less dense up through here, more dense up through here.
Super dense material in through here.
And the closer the spacecraft gets,
the more subtle those variations become between the elongation of these layers,
and the gravitational pull that they feel For now,
we haven't had space crafts efficiently close to really do this, to measure
what's going on in detail in what's called the density profile of Jupiter.
There's a mission that's at Jupiter right now will do precisely this.
We'll talk about that at the end of this unit on giant planets.
Even this Cassini spacecraft, which has been in orbit around Saturn for
such a long time, has been in a distant orbit
unable to measure much other than the very highest order effects.
But as Cassini Gets to its ends of its life, they will eventually
orbit it really close to a Saturn before it plunges into the atmosphere.
In those really close orbits will have the opportunity to
really see a detail what the Dead Sea structure is like.
For now with the modernly good measurements we have I
will tell you that it is consistent with the idea that Jupiter has.
Heavy material in it just like we said before and
that that heavy material is concentrated in a core.
Remember the alternative was that heavy material was throughout Jupiter like this.
This core of material on the inside of Jupiter, this 15 Earth mass core Is
a huge clue into how Jupiter formed.
How it assembled itself from the original material of the solar system.
We'll talk in detail about that at a later class, but as we talk about that,
in that later class, remember that this measurement of the core on Jupiter is
still probable, but not certain.
And when we talk about different ways of forming it,
remember that it might be the other way around where this material is distributed
much more uniformly throughout the planet.
And that's one of those key things that the Juno spacecraft,
its really big solar panels is orbit around Jupiter to try to find out.