1578
Sea Level
(imgs.xkcd.com)
A place for majestic STEMLORD peacocking, as well as memes about the realities of working in a lab.

Rules
This is a science community. We use the Dawkins definition of meme.
We probably won't have better data soon. Actually resolving planets directly is incredibly far out of reach. Measuring their core is implausible.
The core, no, but detecting the effects of a magnetic field are not out of the question.