Word Bank:
|
life |
hours |
miles per hour |
|
gases |
moon |
Autumn |
|
third |
aphelion |
sunlight |
|
nitrogen |
93 million |
Earth |
|
planet |
seasons |
July |
The Earth is the
___________________________ 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 ___________________________. The Earth is
about 7,926 miles (12,756 km) in diameter; it is the fifth-largest
___________________________ 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
___________________________ (11,180 m/sec).
The Earth's atmosphere is a thin
layer of ___________________________ that surrounds the Earth. It
composed of 78% ___________________________, 21% oxygen, 0.9% argon,
0.03% carbon dioxide, and trace amounts of other gases.
The Earth has one
___________________________. 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
___________________________
during a catastrophic collision of a huge body with the Earth billions
of years ago.
On average, the Earth orbits at
___________________________ 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
___________________________) around
___________________________
2 each
year (when we are 94.8 million miles = 152.6 million km from the Sun).
Each day on Earth takes 23.93
___________________________. 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 ___________________________ of the year:
Summer, Spring, Winter and ___________________________. 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
___________________________ each receives.
