A Class-E planet designates a world that is very similar to Earth. Its primary characteristics are similar size to Earth, temperate and varied climate, oxygen/nitrogen atmosphere, and a large amount of surface water. Earth is the model for the class. Among the Class-E worlds in the Compact include Earth, Tian, and Dakota.
Average atmospheric pressure: 800-1200 millibars
Typical atmospheric content: 60-80% hydrogen, 12-30% oxygen, other elements in non-lethal levels or combinations
Diameter: 9000-14,000 km
Average temperature range: -200◦ – 50◦ C
Gravity: .7 – 1.3 g
Additionally, Class-E worlds have active magnetic fields, 30-80% water coverage, multiple and varied climates, and generally (but not always) an abundance of complex life forms.