the.com/terrestrial planet
a planet that grew up solid instead of puffing into a gas cloud.
means a small, rocky, dense planet with a hard surface, unlike the bloated gas giants further out.
from from latin terra, earth — coined to distinguish rocky worlds like earth, mars, venus, and mercury from the gaseous outer planets that never bothered forming a crust.
solar system countonly four exist: mercury, venus, earth, mars
formation zoneborn close to the sun where ice couldn't survive
density edgefar denser than any gas giant despite being smaller
core structurelayered like an onion: core, mantle, crust