inner planets
Mercury through Mars
The inner planets are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars.
Also called terrestrial planets, they share characteristics that distinguish them from the outer planets—they're relatively small, rocky, and dense, with solid surfaces rather than gaseous compositions.
The inner planets orbit within the asteroid belt.
Covered with stones
- terrestrialRelating to land
- silicateOxygen-bound crystal compound
- iron coreCentral metallic magnetic component
- mantleCovering or wrap
crust · dense · differentiated · basaltic · volcanism · cratered · solid surface · regolith
All life on Earth
- hydrospherePlanet's total water mass
- atmosphereGaseous layer around planets
- oceansVast saltwater bodies
- continentsEarth's largest landmasses
tectonics · climate · seasons · life · water cycle · magnetic field · ozone layer · ecosystems
Predawn planet or weapon
- evening starVenus after sunset
- VenusianOf the second planet
- greenhouse effectAtmospheric heat retention mechanism
- volcanic plainsFlat areas from cooled lava
Magellan · atmospheric pressure · longest day · Akatsuki · coronae
Massive Martian shield volcano
- PhobosMars's largest moon
- DeimosMars's outer satellite
- dust stormsWindblown particulate weather events
- polar ice capsFrozen regions at Earth's extremes
Curiosity · Perseverance · Ingenuity · iron oxide · terraforming · thin atmosphere · water ice · colonization
Oval-shaped or indirect
- proximityNearness in space
- eclipticSun's apparent annual path
- transitMovement between places
- elongationIncrease in length
conjunction · opposition · Kepler · perihelion · aphelion · gravitational · retrograde motion · astronomical unit
Central metallic magnetic component
- extreme temperaturesSevere heat or cold conditions
- MESSENGERMercury-studying space probe
- exosphereAtmosphere's outermost region
- solar windsStellar plasma streams
Hermes · tidally locked · scarps · eccentric orbit · magnetic field
rocky
Covered with stones
- terrestrialRelating to land
- silicateOxygen-bound crystal compound
- iron coreCentral metallic magnetic component
mantle · crust · dense · differentiated · basaltic · volcanism · cratered · solid surface · regolith · tectonics
biosphere
All life on Earth
- hydrospherePlanet's total water mass
- atmosphereGaseous layer around planets
- oceansVast saltwater bodies
continents · tectonics · climate · seasons · life · water cycle · magnetic field · ozone layer · ecosystems · biodiversity
morning star
Predawn planet or weapon
- evening starVenus after sunset
- VenusianOf the second planet
- greenhouse effectAtmospheric heat retention mechanism
Magellan · volcanic plains · atmospheric pressure · longest day · Akatsuki · coronae
Olympus Mons
Massive Martian shield volcano
- PhobosMars's largest moon
- DeimosMars's outer satellite
- dust stormsWindblown particulate weather events
polar ice caps · Curiosity · Perseverance · Ingenuity · iron oxide · terraforming · thin atmosphere · water ice · colonization
elliptical
Oval-shaped or indirect
elongation · conjunction · opposition · Kepler · perihelion · aphelion · gravitational · retrograde motion · astronomical unit
iron core
Central metallic magnetic component
- extreme temperaturesSevere heat or cold conditions
- MESSENGERMercury-studying space probe
- exosphereAtmosphere's outermost region
solar winds · Hermes · tidally locked · scarps · eccentric orbit · magnetic field
- planetsEarth, Mars, Jupiter, Saturn, Venus
- solar systemsun, Earth, Mars, Jupiter, Saturn
- spacespace, sun, moon, stars, star
- astrologyastrology, zodiac, horoscope, horoscopes, birth chart
- space scienceastronomy class, cosmology, stars, space exploration, galaxies
- space explorationrockets, Saturn V, satellites, mission, Falcon Heavy
inner planetsouter planets
Planets past the asteroids
gas giants · giant planets · ice giants · Neptune · Uranus
inner, planet, planets, inward, inwardly, inwards, innermost, planetary, interplanetary