Earth is the third planet in our Solar system. It is the largest of the four terrestrial planets namely Mercury, Venus, Earth, and Mars.
Earth formed some 4.54 billion years ago.
In size, Earth is slightly larger than Venus.
Earth is the only known planet that supports life.
is estimated that life initiated in the oceans some 3.8
billion years ago.
the planets have been named after some Greek or Roman God but not Earth.
Earth is composed of four main layers – inner core,
outer core, mantle, and crust.
is the fifth largest planet in terms of size
Light from the Sun reaches
in approximately 8 minutes and 20 seconds.
Earth is not a perfect sphere. It is a unique shape called a geoid,
which means ‘Earth shaped’.
The study of the shape of the Earth is called geodesy. In the past,
geodesy depended on ground-based surveys. Today, satellites play a major role.
Earth is also the only place in the solar system where water is present
in all the three states – solid, liquid and gas.
Earth is also known as the “Blue Planet” because of its bluish appearance from the outer
space. Almost 70% of Earth’s surface is covered with water.
Earth is constantly moving. Thus, the surface of the earth at the
equator moves at a speed of 460 meters per second–or roughly 1,000 miles per hour. You may feel like you’re
standing still, but you’re actually moving and moving quite fast.
Earth spins faster at the Equator than at the Poles, because the Equator
is farther from the Earth’s spinning axis.
The extra speed of the Earth at the Equator flings it out in a bulge,
while it is flattened at the Poles.
The speed of
rotation of Earth is gradually slowing down; meaning that in some 140 million years from now, the length of a day on
Earth would be 25 hours.
Equatorial bulge was predicted in 1687 by Isaac Newton. The equatorial
bulge was confirmed 70 years after Newton – by French surveys in Peru by
Charles de La Condamine, and in Lapland by Pierre de Maupertuis.
The Earth’s diameter at the Equator is 12,758 km. This is larger, by 43 km,
than the vertical diameter from North Pole to South Pole.
The official measurement of the Earth’s radius at the Equator is
6,376,136 m plus or minus 1 m.
Earth has strong
magnetic field due to the presence of inner Nickel-Iron core. This magnetic field is also responsible for
preventing heavy solar winds from blowing on the Earth and causing damage to
various life forms.
Earth is the only
planet in the solar system that has tectonic
its surface. These plates are floating on top of the magma inside of the Earth.
When these plates collide, earthquakes happen. Movement of these plates is also
very important for other geological and life-supporting purposes.
There are five layers in Earth’s atmosphere including – the
Troposphere, the Stratosphere, the Mesosphere, the Thermosphere, and the
Exosphere. Earth’s atmosphere is the thickest from ground level up to a height
of 50 km and extends up to 10,000 km.
highest point: The peak of Ecuador’s Mount Chimborazo, located just one degree
south of the Equator is the highest point on Earth. At this point, the Earth’s
bulge is greatest.
deepest known place: “Challenger deep” – near a trench called the “Mariana
Trench” beneath the surface of the Pacific Ocean to the southeast of Japan — is
the deepest known place on Earth. This trench is nearly seven miles deep.
highest recorded temperature: it is 56.7°C (134°F), measured on 10 July 1913 at
Greenland Ranch, Death Valley, California, USA.
The coldest permanently inhabited place: Oymyakon, a village in Siberia, Russia, is where the temperature reached -68 degree Celsius. And the coldest temperature ever recorded on Earth was at Antarctica’s Vostok station – minus 89.2 degree Celsius.
Wettest place: Mawsynram in Meghalaya, India is the wettest place on land on Earth. It receives an average annual rainfall of 11,871 mm. This place is just 10 miles away from the town of Cherrapunji (another record holder for the wettest month and year ever recorded.)
Driest place: Dry Valleys in Antarctica is the driest place on Earth. This place has seen no rainfall for the past 2 million years. This is a 4800 square kilometer region with no ice, snow or water.
Flattest country: the Maldives is the flattest country in the world with an average highest above sea level of 2.4m.
The Nile is the longest river
on Earth that extends 6,695 km from its source in Burundi to the Mediterranean
sea. However, Amazon is the biggest river in the world in terms of the water
that flows down it.