How do scientists know (with some certainty) the composition of planets’ (w/in our solar system) interior and core make up? How do they guesstimate the radius of the core? Thanks.

Question

An example of this is Mars. Here is a quote from Mars’ Wikipedia Page:

“Current models of its interior imply a core with a radius of about 1,794 ± 65 kilometres (1,115 ± 40 mi), consisting primarily of iron and nickel with about 16–17% sulfur.”

How the heck can this be estimated?

In: Geology

Answer 1

We can tell what the composition of the earth’s interior is by measuring seismic waves emitted by Earthquakes different materials affect the waves in certain ways such as speed and direction changes and we can measure that and I think we do the same for other planets using probes also I believe by observing a planets magnetic field we can get an idea of what’s under the surface but don’t quote me on that I’m not entirely sure