Earth
Earth is a very special planet, being that it is the only planet
in our solar system to support life. This is most likely because
of the water on Earth, water which covers nearly 70% of the
Earth’s surface (3). We have a fragile atmosphere consisting
of 78% Nitrogen, 21% oxygen, and 1% other gasses (3). The
atmosphere on Earth protects us from nearly all harmful radiation
from the Sun and also protects us from meteors by having them
burn up before impact (3). Our atmosphere swells by day and
contracts by night due to solar activity (3).
On the surface, Earth is covered by many interesting features
such as mountains, volcanoes, plains, oceans, rivers, and lakes.
Hot springs, volcanoes, and the high temperatures inside mines
tell us that Earth’s interior is very hot (2). The
temperatures on the surface of the Earth can range from 58º C to
-90º C (1). The four seasons we experience are a result of Earth
being tilted more than 23º on its axis (3). It revolves around
its axis in approximately 24 hours, and it revolves around the
sun in about 365.26 days (1). Earth is 150 million km from the
Sun, has a diameter of 12,756 km, and has one moon.