The Solar System

accretion albedo altitude ammonia asteroids astronomer atmosphere atoms axial period bodies carbon centre of mass comets consist convection core crust Cytherean density depleted depth diameter distance dust Earth equatorial gases gravitational greater haze heat helium hydrogen hydrostatic equilibrium icy materials impact craters indicates interior iron isotopes Jovian Jupiter kg/m³ late heavy bombardment lava less liquid lunar magnetic dipole magnetic field magnetosphere mantle mare Mars Martian massive Mercurian Mercury methane molecular clouds molecules Moon motion Neptune observations oceans orbital period outer outlined in section oxygen particles planetary polar pressure radar radius regions result ring rocks satellites Saturn semi-major shown in Figure sidereal sidereal orbital period silicates solar radiation solar relative abundances Solar System solar uv radiation solar wind spacecraft spin axis star surface temperatures synchronous rotation terrestrial planets theories thermosphere tidal Titan Uranus Venus volatiles wavelengths waves yield