Earth

Earth is the third planet from the Sun and the only astronomical object that is confirmed to harbor life, including plants, animals, fungi, microbes and protists. Earth is often used as a benchmark for a habitable planet because of this, although there are theorized forms of life on very inhospitable objects such as icy objects with underground water (like Europa). Earth is a terrestrial planet composed primarily of oxides, iron, and water and is the largest, most massive, and densest terrestrial planet in our solar system. About 70% of the surface is covered in salt water oceans, and the remainder consists of continents and islands. The current average surface temperature is 14.76 °C, at which water is liquid under atmospheric pressure. Earth is unique for it's relatively large moon], [[The Moon which is a quarter of the size of the Earth and is the 5th largest moon in the solar system.