Earth is the third planet from the sun and home to the only known life. It's the model of what we would want terraformed bodies to look and feel like, in simplest terms.
[Dry] Atmosphere: 78.08% Nitrogen, 20.95% Oxygen, 0.93% Argon, and 0.039% Carbon Dioxide.
Surface Temp: Minimum:-89.2 degrees celsius. Mean: 15 degrees celsius. Maximum: 56.7 degrees celsius.
[Sidereal] Rotation Period: 23hr 56min 4.1sec
Surface Gravity: 9.80665 m/s^2