The Solar System : The Solar System An Intro
www.CBSEQuestionPaper.com About the lesson…. : About the lesson…. Things we will learn: Components of our Solar System.
Relative positions of our planets.
Some Interesting facts about space!!!
More about Sun.
What are Planets & Satellites??
Terrestrial and Jovian Planets.
About Asteroids, Meteors and Comets.
Internal Structure of Earth An Introduction : An Introduction Solar System consists of:
The Nine Planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto)
Large number of Asteroids between the orbit of Mars and Jupiter
Large number of Comets revolving around sun in highly elliptical paths. Lets See How It Looks Like.. : Lets See How It Looks Like.. Planets revolve around the sun and also rotate about there own axis. All planets, except Pluto, revolve in almost the same plane. Some Interesting Facts : Some Interesting Facts Do you know?????
Sun accounts for 99.9% of the mass of the solar system.
Mercury is the smallest planet.
Jupiter is the largest planet.
Alpha Centauri is the nearest star to our solar system (about 4.3 Light Years)
Cirus, the brightest star, is about 8.7 light years away from us.
Only Earth has life on it among all the planets in our solar system. Sun The centre of Attraction!! : Sun The centre of Attraction!! It is the nearest star from us and hence looks much bigger than other stars.
The sun has a diameter of about 1, 392, 000 Km (about 109 times the diameter of earth!!!!)
Sun is about 333000 times as heavy as Earth.
Average distance of sun from earth is 15 crore Km
Light takes about 500s (about 8 minutes) to travel from sun to earth.
The temperature at the core of Sun is about 14 x 106 Kelvin. Sun is the source of energy for earth. It is made up of Hydrogen (70%), Helium (28%) and other gases like Nitrogen, Oxygen and Carbon (2%). The energy is produced in the Sun due to Nuclear Fusion Reaction in which four hydrogen nuclei fuse to form a Helium nuclei (and two positrons). The Planets : The Planets What are they?
The heavenly bodies that revolve around the stars (like Sun) in an orbit are known as planets.
e. g. there are Nine planets in our solar system. They have different structures due to their different temperatures. These have been divided into two types depending upon their similarity of structure.
Jovian Planets. Terrestrial Planets : Terrestrial Planets The four planets near to Sun, namely Mercury, Venus, Earth and Mars are known as Terrestrial Planets because their structure is similar to Earth. Common Features of these planets are:
A thin rocky crust.
A mantle rich in Iron and Magnesium
A core of Molten Metals.
Very few moons The first colour image of the Martian Surface, transmitted by Viking 1 Lander on July 26, 1976. (NASA) Jovian Planets : Jovian Planets The five planets beyond the orbit of Mars are known as Terrestrial Planets because their structure is similar to Jupiter. These are Jupiter, Saturn, Uranus, Neptune & Pluto. Common Features of these planets are:
They are Gaseous Bodies
They have ring system around them.
Except Pluto they all have a large number of moons (i.e. natural satellites). Pluto has only one moon.
They are too distant from Sun as compared to Terrestrial Planets. How to remember their Sequence? : How to remember their Sequence? Just remember the phrase.. My
Pluto A brief intro - Mercury : A brief intro - Mercury Nearest to Sun
Very Hot during Day and Very Cold at night. A brief intro - Venus : A brief intro - Venus Closest to Earth
Size almost same as Earth
Visible before dawn and after sunset.
Known as Morning (or Evening) Star
Called sister planet of Earth due to similarities. A brief intro - Earth : A brief intro - Earth Diameter: 12 800 Km
Mass: 6 x 1024 Kg
Rotation time: 24 hours.
One Revolution: 365 ¼ days
Only Planet that can sustain life.
Has Nitrogen and Oxygen rich atmosphere. A brief intro - Mars : A brief intro - Mars Known as RED PLANET
Has two Moons
Has a lot of solid CO2. A brief intro - Jupiter : A brief intro - Jupiter Largest Planet
Can contain as many as 1300 earths!!!!!!
Covered by clouds of gases
Has 28 Moons !!
Storms are always raging on its surface A brief intro - Saturn : A brief intro - Saturn Has beautiful rings around it
Has 30 moons in addition to rings!!
Appears bright yellow. A brief intro - Uranus : A brief intro - Uranus Very Cold
Has 21 moons in addition to rings A brief intro - Neptune : A brief intro - Neptune Very far from Sun
Has 8 moons. A brief intro - Pluto : A brief intro - Pluto Farthest planet
Has just one moon Satellites : Satellites What are they?
The heavenly bodies that revolve around the PLANETS (like Earth) in an orbit are known as satellites.
e. g. Moon is the satellite of Earth. It revolves around earth in an elliptical orbit. Other planets like Mars, Jupiter and Saturn also have their satellites Moon’s Surface Asteroids : Asteroids The small rock like bodies revolving around Sun between the orbits of Mars and Jupiter are called Asteroids.
These are very small to be considered as Planets. The largest among them is Ceres with a radius of about 800 Km only while the smallest one is as small as a pebble.
Where did they come from?
It is believed that they were formed due to some collision between planets which resulted into its breaking into small fragments. Though their exact origin is not known till date. Asteroid Named GASPRA Asteroid Named IDA
(Along with its tiny satellite) Meteors (Shooting Stars) : Meteors (Shooting Stars) These are pieces of rocks floating in space, which sometimes enter the earth’s atmosphere. They experience a force of friction of air and start burning. They appear as a ball of fire falling towards earth emitting intense light. They are also known as Shooting Stars but they are not actually Stars or in anyway connected to them. Most of them get completely burnt in the atmosphere. Meteorites Some meteors are so large and do not get completely burnt. So they reach earth and are known as Meteorites. Comets : Comets These are heavenly bodies which revolve around the sun in highly elliptical paths. They appear in the sky as a ball of fire with a TAIL. The tail always pointing away from the Sun. e.g. HALLEY’S COMET Why do they have tail???
They are composed of rocks like material surrounded by large masses of easily vaporised substance like water, ammonia, methane etc. When these approach Sun, some of its material gets vaporised due to heat of the Sun. Light of the Sun exerts pressure on these vapours and forces them away from the comet in form of a tail.
Are they Important?
Yes, from the analysis of their material we can know about the origin of Universe and the life of Universe. Halley’s Comet
It has a time period of 76 years. Last seen in 1986 and will now be visible in 2062. Structure of Earth : Structure of Earth Crust Mantle Outer Core Inner Core The Earth can be broadly divided into Three different Layers. Structure of Earth : Structure of Earth Earth is composed of a number of layers. Though we have not been able to dig more than 10 Km into the earth’s crust but we have studied it in details from the study of Seismic Waves.
Seismic waves are produced during Earthquakes. But in addition to natural seismic waves we can also produce artificial waves by Underground Nuclear Tests.
Velocity of seismic waves depends on composition of region from which they pass. From the study of their velocities we can collect more information and a picture of earth’s interior. Three layers of earth are: The Three Layers- A Comparison : The Three Layers- A Comparison Crust:
a. Top 30-40 Km layer of earth.
b. Contains mainly rocks of silicates (Containing SiO2).
c. Its thickness is lesser under sea floor.
a. From 40 km – 3000 Km.
b. Rich in Iron and Magnesium Silicates.
c. Not under direct observation.
a. Innermost layer beyond 3000 Km.
b. It consists mainly of Pure Iron alloyed with some Nickel.
c. Its material is in FLUID state. Slide 27: True or False 1. Meteors that reach Earth are called Meteorites. 2. Planets revolve around their satellites. 3. There are Nine Planets in our Solar System. 4. Asteroids are there between the orbits of Mars and Saturn 5. Mercury is the nearest planet to the Sun. True False know your knowledge … : know your knowledge … Q1. _________ is NOT a planet.
Mars know your knowledge … : know your knowledge … Q2. The debris present between the planets Mars and Jupiter are called __________.
Asteroids know your knowledge … : know your knowledge … Q3. The ratio of diameter of Sun to that of earth is _______
33000 know your knowledge … : know your knowledge … Q4. Morning and Evening Star is the name given to the planet _______
Neptune know your knowledge … : know your knowledge … Q5. Hottest Planet in our Solar System is:
Earth Slide 33: I Know !!! There are ???? planets in our solar system. They are ?????, Venus, Earth, Mars, ???????, Saturn, Neptune and ????. They ?????? around Sun and rotate about their own axis. ??? is at the centre and accounts for about 99.9% of the mass of solar system. Planets have been classified into two types namely ?????? planets and ??????? planets depending on similarity of their structures. Beside these planets our solar system has Asteroids between the orbits of ???? and ??? Then we have ?????? which revolve around sun in highly elliptical paths. We can see ?????? ????? after every 76 years. Slide 34: I Know !!! There are nine planets in our solar system. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune and Pluto. They revolve around Sun and rotate about their own axis. Sun is at the centre and accounts for about 99.9% of the mass of solar system. Planets have been classified into two types namely Terrestrial planets and Jovian planets depending on similarity of their structures. Beside these planets our solar system has Asteroids between the orbits of Mars and Jupiter Then we have comets which revolve around sun in highly elliptical paths. We can see Halley’s comet after every 76 years. Slide 35: Home Work Q 1. Name the nine planets of our Solar System.
Q 2. What is a comet?
Q 3. Why is life only possible on earth?
Q 4. Define following terms:
Q 5. Differentiate between Jovian and terrestrial planets. Slide 36: From:
Class X Students