Solar System

Chapter

Solar System

Definition– It is our Sun and everything that travels

around it

• Nearly 5 billion years old

• It is nestled inside a very large galaxy of stars called the Milky Way

• Our Solar System is elliptical in shape

• It is made up of – Eight planets– Dwarf planets– Around 170 moons– Other celestial bodies

The Big Bang Theory

• According to the Big Bang theory, our Universe burst into sudden existence in a massive explosion called the Big Bang

• It occurred around 13.7 billion years ago if the theory is valid

• Nobody knows what was there before the Big Bang

• At that time, the entire Universe was inside a bubble that was thousands of times smaller than a pinhead

• It was hotter and denser than anything we can imagine

• The theory maintains that, in the instant—a trillion-trillionth of a second—after the big bang, the universe expanded with incomprehensible speed from its pebble-size origin to astronomical scope

• Scientists can't be sure exactly how the universe evolved after the big bang.

• Many believe that as time passed and matter cooled, more diverse kinds of atoms began to form, and they eventually condensed into the stars and galaxies of our present universe

Sun

• Center of the Solar System

• Closest star– An enormous ball of burning gases

• Name Sol– That is why our system of planets is

known as Solar System

Sun

• Contains around 99.8% of total mass of the Solar System

• Sun spins slowly on its axis – 25 to 36 days

• Temperature – Over 1,000,000 Kelvin – Emits intense light and solar

radiation

– Sun being gigantic with a powerful gravity attracts all the other objects in the Solar System towards it

• Two phenomenon occur simultaneously:

– These objects, which are moving very rapidly, try to fly away from the Sun, outward into the emptiness of outer space

• As a result of the two forces –They spend eternity orbiting around their parent star

Planets

• Planets are Sun’s satellites

• A Greek word meaning wanderer

Definition– A celestial body moving in an elliptical

orbit around a star

Planet

Controversy

• In 2005– The issue of a clear definition for planet

arose with the discovery of the trans-Neptunian (literally "beyond Neptune") object named Eris, a body larger than the smallest then-accepted planet, Pluto

• In 2006 – The International Astronomical Union

(IAU) redefined what a planet is

– Under this new definition, Pluto, along with the other trans-Neptunian objects, do not qualify as a planet

• Many scientists have accepted the definition, some in the astronomical community have rejected it outright.

Properties of a Planet

• Must orbit a star

• Does not emit light

• Must be large (3032 miles) enough so that its own gravity pulls it into the shape of sphere

• Clears smaller objects out of its orbit by attracting the small bodies into itself

List of Planets

Following is the list of planets:

1. Mercury2. Venus3. Earth4. Mars5. Jupiter6. Saturn7. Uranus8. Neptune

Mercury

• Messenger of the gods– Mercury revolves around the sun

fast and was known to be swift on foot

• Smallest planet

• Closest planet to the Sun

• Movement– Revolution 88 Earth days– Rotation 59 Earth days

• Moons None

Merc

ury

• Called a Morning Star– Because it shines brightly in the

early morning, just before the sun rises.

• Also called an Evening Star– Because it shines brightly just

after the Sun sets for a brief period of time

Venus

Ven

us

• The goddess of love and beauty

– Venus is known to be the most beautiful planet in our solar system

• Brightest object at night-time– Reflective clouds

• Earth’s sister planet– Almost identical in size– Made up of almost the exact

same types of materials

• Why does not life exist?

– Does not have an ozone layer• As a result, the ultraviolet radiation

from the Sun finds its way directly into Venus' atmosphere

– Consists of 97% carbon dioxide• Which creates a massive greenhouse

effect that overheats the planet

– Atmosphere is toxic • Contains clouds of sulfuric acid,

chlorine, and fluorine

• Moon None

• Movement– Revolution 225 Earth days– Rotation 243 Earth days

• Rotates very slowly, so that a day on Venus actually lasts longer than a year

• Rotates in the opposite direction as almost all the other planets

• The highest mountain Maxwell Montes, comparable to Mount Everest

Earth

• Our Home Planet

• The only planet to harbor life

• Third planet from the sun

• The fifth largest planet

• Moon One– Its name is Luna 

Eart

h

Mars

• The god of war – Mars is red…the color of war

• Also known as the Red Planet

• Moon 2– Phobos– Deimons

• The largest volcanic mountain in the solar system Olympus Mons– 3 times taller than Mount Everest

Mars

• Movement– Revolution 687 Earth days – Rotation 24 hours and 27

minutes

• Mars once had rivers, streams, lakes, and even an ocean

• Today the only water on Mars is either frozen in the polar caps, or underground

Jupiter

• King of gods – This is the largest and most

magnificent of the planets

• After sun, Jupiter contains most of the mass

• Largest planet

• Has no solid surface; made mostly of hydrogen and Water

• Moon 63

Jup

iter

• Movement– Revolution 4,331 Earth days– Rotation 10 hours (spins really

fast)

• Great Red Spot A huge storm that has existed for nearly 400 years– Very much like a hurricane on

Earth– Large enough to fit three Earths

Saturn

• The god of agriculture

• Like Jupiter, Saturn is made mostly of hydrogen, methane and helium

• The most windiest and lightest planet as hydrogen and helium are the two lightest elements in the universe

• Moon 61• It spins very fast due to lighter weight

Satu

rn

• The most extensive ring system– Consists of chunks of ice and

dust and rocks.– They are more than half a mile in

size (0.62 miles)

• Movement– Revolution 10,759 Earth days– Rotation 10 hours and

13minutes

Uranus

• Lord of the skies - Uranus• It is a gas giant

• The blue planet– Due to methane gas in its

atmosphere

• Spins on the axis which points directly towards the sun

• Moon 27

• Rings 11

Ura

nu

s

• Movement– Revolution 30,687 Earth days– Rotation 17 hours

Neptune

• The god of water/sea– Because the color of the planet is

blue

• Last planet

• Has a blue tinge – Because its atmosphere is a mixture

of hydrogen, helium and methane

• Moon 13

• Rings 6

Nep

tun

e

• Movement– Revolution 60,190 Earth days

or once every 165 years– Rotation 16 hours

Classification of Planet

• Categorized in the following ways:– By composition

• Terrestrial or Rocky planets• Jovian or Gas planets

– By size• Small planets• Big planets

– By position relative to the Sun• Inner planets• Outer planets