Mercury vs. Neptune vs. Venus

Discovery

Discovered By

Unknown

n/a

n/a

Discovery Site

Unknown

n/a

n/a

Discovered At

Prehistoric

n/a

n/a

Physical Characteristics

Mean Diameter

Volume

Mass

Mean Density

Surface Gravity

Mean Temperature

Atmosphere Characteristics

Surface Pressure

Composition

42% O, 29% Na, 22% H

80% H, 19% He

97% CO2, 3% N

Surroundings

Natural Satellites

Ring System

No

No

Global Magnetic Field

Yes

No

Orbital Characteristics

Median Orbital Radius

Apoapsis / Aphelion

Periapsis / Perihelion

Sideral Orbital Period

Sideral Rotation Period