The galileo spacecraft dropped a probe into jupiter's atmosphere that survived 200 km, or 0.3% of jupiter's radius. which is the deepest layer that this probe was able to directly sample?

Gaseous Hydrogen Layer

Explanation:

The reason the deepest layer that this probe was able to directly sample is just the gaseous hydrogen layer is because Jupiter's upper atmosphere is about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules. So the 200km this problem was able to cover is still composed of gaseous hydrogen.