Breif discussion:
Earth is the only planet to be covered with a large percent of water and an atmosphere made of mostly nitrogen and oxygen. If the conditions of position, atmosphere, or size and mass were any different then they are on Earth, then we would not live here. Earth is the largest of the four inner planets.
In detail:
# Planet Away from the Sun: 3
Diameter: 12.75 km
Size comparison with Planets: 5th
Rotation period: 23 hrs 56 mins 04 secs
Distance from Sun: 147-152 million km
Visibility: Uhhh, look down.