GK Question: The Solar System for competitive Exam
The sun
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It contains 99.8 per cent of the solar
system’s mass and is a hot ball of glowing gases
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Planets orbit the sun in oval-shaped paths
called ellipses, with the sun slightly off-centre of each ellipse.
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The sun is by far the largest object in our
solar system.
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Without the Sun’s energy, there will be no
life on earth.
The Planets of Solar System
The closest four planets namely Mercury,
Venus, Earth, and Mars are termed terrestrial planets, which means they have a
hard rocky surface. The farthest four planets of solar system namely Jupiter,
Saturn, Uranus, and Neptune are called gas giants. These planets are much
larger and their surface is composed of gas elements (mostly hydrogen). There
are eight planets in our Solar System that are revolving around the Sun in
elliptical orbits.
1. Mercury
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It takes only about 88 days to complete one
round along its orbit.
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It takes 59 earth days complete one Spin on
Axis (One Earth Day)
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It is the nearest planet to the sun.
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It is the smallest planet of our solar
system.
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It can be observed just before sunrise or
just after sunset, near the horizon.
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Mercury has no satellite/moon of its own.
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Fastest revolution time.
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Extreme weather +400°C & –200°C.
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Mercury is also known as the Roman God of
Commerce.
2. Venus
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It takes only about 225 earth days to
complete one round along its orbit.
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It takes 243 earth days complete one Spin on
Axis (One Earth Day)
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It is the brightest planet in the night sky.
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It is the hottest planet.
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It is often called as a morning or an evening
star although it is not a star.
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Venus is considered as the ‘Earth’s-twin’
because its size and shape are very much similar to that of the earth.
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Venus has no moon or satellite of its own.
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It rotates from east to west while the Earth
rotates from west to east.
3. The Earth
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It is known as the Blue Planet.
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It is slightly flattened at the poles. Hence,
its shape is described as a Geoid.
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It takes 24 hours complete one Spin on Axis
(One Earth Day)
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It takes only about 365 days to complete one
round along its orbit.
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The Earth has only one moon.
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The earth is the 3rd nearest planet to the
sun, it is the fifth-largest planet.
4. Mars
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It appears slightly reddish due to the
presence of iron oxides and, hence, it is also known as the red planet.
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It is also known as the Roman God of war.
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It takes 24 hours complete one Spin on Axis
(One Earth Day)
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It takes only about 687 Earth days to
complete one round along its orbit.
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Mars has two small natural satellites or
moons.
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Nix Olympia is a mountain spotted in Mars
which is 3 times higher than Mountain Everest.
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The name of two Satellites are Phobos and
Deimos.
5. Jupiter
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It has 75 moons or natural satellites.
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It has faint rings around it.
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It rotates very rapidly on its axis.
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It takes 10 Hours complete one Spin on Axis
(One Earth Day)
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It takes only about 4333 earth days to
complete one round along its orbit.
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Jupiter is the largest planet of the solar
system.
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The mass of Jupiter is about 318 times that
of our Earth.
6. Saturn
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It has 82 moons or natural satellites.
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It is the least dense among all the planets.
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It is the second-largest planet of the solar
system.
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It looks beautiful because of the rings. It
has 7 main rings.
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It takes 10.7 Hours complete one Spin on Axis
(One Earth Day)
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It takes only about 10759 earth days to
complete one round along its orbit.
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Saturn also has a large number of satellites.
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Saturn appears yellowish in colour.
7. Uranus
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It is called Green Planet because of the
presence of Methane gas.
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It takes 17 Hours complete one Spin on Axis
(One Earth Day)
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It takes only about 30687 earth days to
complete one round along its orbit.
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Like Venus, Uranus also rotates from east to
west.
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Uranus has five major moons: Miranda, Ariel,
Umbriel, Titania, and Oberon. It has a total 27 moons.
8. Neptune
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It is the Coldest planet and the windiest
planets.
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It takes 16 Hours complete one Spin on Axis
(One Earth Day)
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It takes only about 165 earth days to
complete one round along its orbit.
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There are 14 Satellites. At least 5 main rings
are present.
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Voyager 2 is the only spacecraft visited
there.
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It is an Ice Giant.