The document discusses the solar system and its key components. It begins by providing context about the universe and galaxies before focusing on the Milky Way galaxy and how the solar system formed. It then describes the eight planets in our solar system - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune - and provides one or two notable facts about each planet and its composition. The document concludes by stating that Pluto is no longer classified as a planet.

1. The solar system
The universe is commonly defined as the totality of everything that exists,
including all physical matter and energy, the planets, stars, galaxies, and
the content of intergalactic spaces. the study of the universe is known
as Cosmology. The galaxy is a vast system of billions of stars, which also
contains a large number of gases and dust. there are about a hundred
billion galaxies in the universe, and each galaxy has an average of a
hundred billion stars. the milky way galaxy is the home of the earth and
our solar system.
The Milkyway galaxy was formed 5 billion years after the big bang, and
the origin of the universe is explained by the big bang theory, formulated
and proposed by the Belgium astronomer and cosmologist Abbe Goerge
Lemaitre.
The solar system consists of the sun, the eight planets, and their
satellites, and thousands of other heavily smaller bodies known as the
asteroids, comets, and meteors. the sun is at the center of the solar
system and all these bodies are revolving around it. the gravitational pull
of the sun keeps all the planets and other objects revolving around it.
Thus the motion of all the members of the solar system is governed

2. mainly by the gravitational force of the sun as we all know the all the
planets revolve around the sun in an elliptical orbit. as a matter of fact,
the sun is the source of energy in the solar system.
Some are the notable facts about planets and their satellites
mercury
• Mercury is the closest planet to the sun and it also the extremely
hot planet in the solar system
• the planet has no water and it does not contain any of the gases
like carbon-dioxide, nitrogen, hydrogen, oxygen
• this planet does not contain any of the protective blankets
like ozone protected around it.
venus
• It is the brightest and nearest planet to our earth
• the venus planet is known as the evening star
• the planet is surrounded by a thick cloud cover which is known as
a veiled planet
• it is similar to the earth size and mass, hence the planet is known as
the earth twin.
• Venus is the hottest planet due to its veil of cloud

3. Earth
• Earth is the only planet which supports life.
• it is the 5th largest planet of the solar system with 3,959 miles of
radius
• earth atmosphere contains almost 78% nitrogen, 21% oxygen, and
1% of other gases like carbon dioxide, water vapor, argon
• By research, our scientists have found that our planet is 4.5 billion
years old.
• earth rotates at a serious speed of 30 km per second.
Mars
• As we all know that mars are called the red planet of the solar
system.
• It is the second smallest planet of the solar system with a diameter
of 6,797 km, half of the earth diameter
• The highest mountains of the solar system prest in the mars which
are whooping 24km high
• the gravity on the mars is much weaker than the earth
• it has two satellites known as phoebes and Demos.
Jupiter
• Jupiter is the largest planet in the solar system
• it is also known as the winter planet the temperature is below -148
degrees
• Jupiter has the shortest days of all the planet which is 9 hours and
55 minutes

4. • its atmosphere consists of the three layers of compressed hydrogen
gas, liquid metallic hydrogen, the core of ice, rock, metals
• Till now eight space crafts are visited the Jupiter planet
Saturn
• It is the most distant planet seen from the naked eye
• Saturn is the flattest planet of all the solar systems and it rotates its
own axis in 10 hours and 34 minutes.
• it rotates the sun every 29.4 earth years
• the Saturn planet is mostly made of hydrogen
• Saturn has the most extensive rings in the solar system which
stretch about 120,700km from the planet, and are amazingly thick
which is 20 meters thick.
• Titan is the largest satellite of Saturn.
Uranus
• Uranus is 4 times the size of the earth this planet appears green in
color because of methane gas present in it.
• it is the coldest planet in the solar system which consists of -201
degrees
• the day at the north pole of Uranus lasts about 84 earth years this
would follow 42 years of darkness.
• it is the second least dense planet in the solar system
• the Uranus atmosphere contains ice.
Neptune
• Neptune is the second-largest gravity planet in the solar system

5. • Neptune takes about 164.8 earth years to orbit around the sun
• the planets spin very quickly on their axis
• on the upper atmosphere of Neptune, the large storms hit at a
speed of 1,340km per second, there the climate on the Neptune is
extremely active
• it has an average atmospheric temperature of about -214 degree
Celcius
pluto is not now a planet, under the IUA's new definition of planets, the
number of planets is reduced from nine to eight.