Word Bank:

     

life	hours	miles per hour
gases	moon	Autumn
third	aphelion	sunlight
nitrogen	93 million	Earth
planet	seasons	July

 

The Earth is the     third    planet from the Sun in our Solar System. It is the planet we evolved on and the only planet in our Solar System that is known to support life. The Earth is about 7,926 miles (12,756 km) in diameter; it is the fifth-largest    planet   in our Solar System. The Earth's mass is about 5.98 x 10²⁴ kg. Earth is the densest planet in our Solar System. To escape the Earth's gravitational pull, an object must reach a velocity of 24,840    miles per hour   (11,180 m/sec).

The Earth's atmosphere is a thin layer of    gases   that surrounds the Earth. It composed of 78%   nitrogen   , 21% oxygen, 0.9% argon, 0.03% carbon dioxide, and trace amounts of other gases.

The Earth has one    moon  . The moon is about one quarter of the diameter of the Earth. The moon may have once been a part of the Earth; it may have been broken off the     Earth    during a catastrophic collision of a huge body with the Earth billions of years ago.

On average, the Earth orbits at    93 million    miles (149,600,000 km) from the Sun. The Earth is closest to the Sun (this is called perihelion) around January 2 each year (when we are 91.4 million miles = 147.1 million km from the Sun); it is farthest away from the Sun (this is called    aphelion  ) around   July    2 each year (when we are 94.8 million miles = 152.6 million km from the Sun).

Each day on Earth takes 23.93   hours  . Each year on Earth takes 365.26 Earth days (that is, it takes the Earth 365.26 days to orbit the Sun once). The Earth's rotation is slowing down very slightly over time, about one second every 10 years.

The Earth's axis is tilted from perpendicular to the plane of the ecliptic by 23.45°. This tilting is what gives us the four   seasons   of the year: Summer, Spring, Winter and    Autumn  . Since the axis is tilted, different parts of the globe are oriented towards the Sun at different times of the year; this affects the amount of   sunlight    each receives.