Earth characteristics compared to other planets (kids explanation)

While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with the life we know or are starting to know of, for example, us as human beings. Just slightly larger than nearby Venus, Earth is the biggest of the four planets closest to the Sun, all of which are made of rock and metal. Other planets such as Jupiter are not so likely to have life like us there, for it is full of gas we don't breathe, and gases which are harmful to us, unlike the oxygen we have here on earth.