|Feature||% of radius|
Every inner planet has a core. The cores of Mercury, Venus, and Earth are composed of iron-nickel. Mars's core is made of liquid iron sulfide mixed with some nickel.
Inner and Outer Cores
Earth and Venus have an inner core and an outer core; the inner core is solid due to the trememdous weight of the matter above it, and the outer core is liquid. Both inner core and outer core have the same composition.
Every inner planet has a mantle. Except for Mercury's, the mantle is a layer which is about of the planet's radius. Every planet's mantle is made of the same stuff: melted silicates mixed with some metallic oxides.
Every inner planet has a crust. The crust ranges from about .5% of an inner planet's radius to about 2%. It is always made of rock silicates and metals in these inner planets.
Although Mercury's blanket of gas can barely be called an atmosphere, every inner planet has one. The atmosphere is where planets show the greatest range; Mercury's is helium at near-vacuum pressures, Venus's is extremely dense and acidic, ours is nitrogen-oxygen, and Mars's is a thin carbon dioxide atmosphere. They extend from the surface a distance of 2 to 3% of each inner planet's radius.
|Albedo||Average: 32%||Minimum: 11%||Maximum: 65%|
|Axal Inclination||Average: 12.9°||Minimum: 0°||Maximum: 25.2°|
|Average Distance to Sun||84,400,000 mi||36,000,000 mi||141,500,000 mi||135,800,000 km||57,900,000 km||227,700,000 km|
|Equatorial Diameter||5,674 mi||3,031 mi||7,926 mi||9,131 km||4,878 km||12,756 km|
|Escape Velocity||4.84 mi/sec||2.67 mi/sec||6.96 mi/sec||7.79 km/sec||4.3 km/sec||11.2 km/sec|
|Grav. Acceleration||21.2 ft/sec²||12.2 ft/sec²||32.1 ft/sec²||6.5 m/sec²||3.7 m/sec²||9.8 m/sec²|
|Mass||6.508 1024 lbs||7.244 1023 lbs||1.317 1025 lbs||2.952 1024 kg||3.286 1023 kg||5.974 1024 kg|
|Mean Density||Average: 5.03 water density||Minimum: 3.94 water density||Maximum: 5.52 water density|
|Number of Moons||Average: 1 (to nearest whole moon)||Minimum: 0||Maximum: 2|
|Orbital Eccentricity||Average: .081||Minimum: .007||Maximum: .206|
|Orbital Inclination*||Average: 4.1°||Minimum: 1.8°||Maximum: 7°|
|Orbital Period||Average: 341.23 earth days||Minimum: 87.97 earth days||Maximum: 686.98 earth days|
|Average Orbital Velocity||76,530 mph||53,980 mph||107,130 mph||123,160 kph||86,870 kph||172,410 kph|
|Polar Diameter||5,661 mi||3,031 mi||7,900 mi||9,110 km||4,878 km||12,714 km|
|Rotational Period||Average: 75.93 earth days||Minimum: 23 hrs 56 mins||Maximum: 243.02 earth days|
|Minimum Temperature||40° F||-350° F||835° F||5° C||-210° C||445° C|
|Maximum Temperature||480° F||80° F||900° F||250° C||25° C||480° C|