Understanding Comparative Planetology
Why Venus is a furnace, Mars a frozen desert, and Earth alive — the handful of processes, of interiors and atmospheres and magnetic fields, that play out to wildly different ends across the worlds. Built on real planetary science; hypothetical world-types are labelled as proposed.
Related entities
- Planetary process
Plate Tectonics
The slow motion of a planet's rigid surface plates over its convecting mantle, continually creating and recycling crust. Earth is the only body where plate tectonics is known to operate today, and it is deeply tied to Earth's long-term climate and habitability.
- Planetary process
Atmospheric Escape
The gradual loss of a planet's atmosphere to space — light gases escaping thermally, the solar wind stripping the air from an unmagnetised planet, or impacts blasting it away. It is why Mars, which lost its magnetic field, also lost most of its once-thick atmosphere.
- Planetary class
Ocean World
A world with a large body of liquid water — most securely the global oceans hidden beneath the ice of moons like Europa and Enceladus, and possibly some water-rich exoplanets. Ocean worlds are among the most promising places to search for life beyond Earth.
- Planetary interior layer
Core
The dense central region of a planet or moon, typically the heaviest material that sank inward as the body formed. In the terrestrial planets it is largely iron; where it is partly molten and convecting, as in Earth, it can generate a global magnetic field.