The Earth is just the right size with a diameter of 7926 miles

Smaller Diameter?

• This would result in a much weaker surface gravity
• As a result, too much water would escape the atmosphere along with other lighter gases
• Therefore, the atmosphere would be poisonous

Larger Diameter?

• This would result in much stronger surface gravity
• Too much ammonia and methane gas would persist in the earth’s atmosphere
• Again, the earth's atmosphere would be poisonous

The Earth is just the right size to support life!