Terrestrial Planets Mercury Venus Earth Mars Source of images Planetary photojournal:
Mercury ☿ Mean radius 2439 km = 0.38R E Mass 3.3 ˣ kg = 0.055M E Mean density 5427 kg/m 3 Rotation period d (length of day) Orbital period 88 d (length of year) → 3:2 spin – orbit resonance Sun distance ~0.387 AU Mercury Volcano
Inner structure 1 Crust 100 – 200 km 2 Mantle -600 km Nucleus – 1800 km Core ~42% of volume Higher iron content than any other planet
Mercury surface map All images: NASA & JHUAPL Messenger Mission
Mercury Kepler Debussy Pantheon Fossae Impact ejecta spokes
Venus Mean radius 6051 km = R E Mass 4868 ˣ kg = M E Mean density 5204 kg/m 3 Rotation period -243 d Orbital period d Sun distance ~0.7 AU Surface pressure 93 bar
Venus Magellan Radar Images Ridges formed by crustal shortening Eistla region with Gula Mons in the Background
Image resolution Venera vs. Magellan
Earth Mean radius 6371 km Mass ˣ kg Mean density 5515 kg/m 3 Rotation period -1 d Orbital period d Sun distance 1 AU Surface pressure 1 bar Earth Moon system to scale
Mars Mean radius 3396 km = R E Mass 6418 ˣ kg = M E Mean density 3933 kg/m 3 Rotation period d = h Orbital period d Sun distance ~1.5 AU Surface pressure 0.7 mbar Opportunity: Greeley Haven winter stopover
Mars “Homestake” mineral, possibly Gypsum vein from Oportunity MRO North polar erg with sand dunes Snake River Rocks, Curiosity
Mars MEX: Buried glaciers around Phlegra Montes
Mars MRO Chemical alteration by water, Jezero Crater Delta