With a radius of 3,959 miles, Earth is the fifth largest planet in our solar system, and it's the only one known for sure to have liquid water on its surface. Earth is also unique in terms of ...

This also guides planetary scientists in their search for other habitable (or inhabited!) worlds in our solar system and beyond! Scientists now think the Earth’s story began around 4.6 billion years ...

MADDIE: There are a lot of stars in our universe ... And when we do that we work out that the Earth, the sun and everything in the solar system is 4.6 billion years old! MADDIE: Jupiter is ...