Basic concept of solar system and planets

OUR SOLAR SYSTEM

BASIC CONCEPT OF SOLAR SYSTEM                                                                                                                                                                                                                                                                  

OUR SOLAR SYSTEM : Our solar system consist of a star (sun), eight planes, Dwarf planets and countless fragments of left-overs called asteroids ,meteors, comets and satellites of the planets called small solar system bodies.



Origin of solar system  : Various theories have been given by different persons to explain the origin of solar system.  Gaseous hypothesis ----  Kant, Nebular hypothesis of ---  Laplace,
Planetesimal hypothesis ---  Chamberlin & Moulton,Tidal hypothesis ---  James jeans & Harold Jaffery, Binary star hypothesis --- H.N Russel, Fission hypothesis --- Ross Gun,Cepheid hypothesis --- A.C Banerji, Nova hypothesis --- Hoyle & Lyttleton, Electromagnetic hypothesis --- H.Alfven,Intersteller dust hypothesis --- Schmidt,Nebular cloud

hypothesis --- Dr. Van Weizsacker, Protoplanet hypothesis--- G. kuiper ,                                                                                      

                                                                     

MERCURY

MERCURY  :It is the closest planet to the sun. ROTATION : 58.65 days, REVOLUTION: 88 days fasted revolution in solar system. Maximam diurnal range of temperature. its days are scorching hot and nights are frigid.It has no atmosphere and no satellite.It is a hot planet.Here has no water on it.Mercury has no gas .it has no protective blanket like ozone around it to prevent us from harmful radiations.Diameter of mercury planet  is 4878 km. It has no satellite.Only one spacecrapt has visited to the mercury.Mercury surface callled when a new nasa mission go to mercury.

VENUS

VENUS

VENUS  Also called Earth's twin because it is slightly smaller than the Earth(500km less in  liameter). Popularly know as evening star and morning star.Brightest object after Sun and Moon.Closest planet to Earth.It is the hottest planet in solar system, it is because of the green house effect as its atmosphere contains 90-95% carbon di oxide. The night and day temperatures are almost the same.Rotates backwards clockwise unlike others.Slowest rotation in solar system 257 days.Almost equal rotation and revolution 224.7 days.

URANUS

URANUS

URANUS : Uranus is about four times the size of the earth. this planet appears greenish in colour because of methane gas present in its atmosphere. Uranus was discovered in 1781 by sir William Hersiel. uranus is the 7th planet from the sun.  ROTATION : 10.8 hrs,REVOLUTION : 84 yrs

Surrounded by a system of 9 faint rings. Has 27th satellites prominent are miranda, ariel etc.              

MARSH

MARS :- Also called red planet. Revolution-687 days, Rotation- 24.6 hrs. almost equal to Earth.

It has a thin atmosphere comprising of Nitrogen and Argon.The highest mountain here is named "nix olympia" which is three times higher than mount Everest.It has to satellites- Phobos and Deimos.

JUPITER

JUPITER:- 5th Planet from the Sun and Jupiter is largest planet of the solar system.Jupiter is also known as winter planet as its average temperature is very low 148 degree centigrade. Jupiter is also called lord of heavens.Its Atmosphere contains hydrogen,helium, methane and amonia. A great red spot is detected on it. It represents a huge storm a super hurricane,existing for hunderd of years, without abating. ROTATION : It has fasted rotation time 9.8 hrs in the solar system. REVOLUTION:12 yrs. It has 66 satellites prominent are  Io,europa, ganymede and callissto called galileo galilei in january 1610. ganymede is the largest satellite of the solar system.Jupiter has been explored on several occasions by robotic spacecraft most natably during the early pioneer and voyager missions and later by Galileo Orbiter. The recent probe to visit jupiter was the pluto-bound new horizons sacecraft in late february 2007.The probe used the grauity from jupiter to increse its speed.

SATURN

SATURN : Named after the Roman God Saturn,it is the sixth planet from the sun and the second-largest planet in the solar system, after jupiter, REVOLUTION :29 yrs ,ROTATION : 10.3 hrs.Saturn has bright concentric rings which are made up of ice-covered dust particles which revolve around it.Titan,the satellite of saturn, is the largest satellite in the solar system .

NEPTUNE

NEPTUNE

         














NEPTUNE :Neptune is the 8th planet of the solar system. The temperature on the surface of neptune remains low. neptune is very similar to uranus and can be considered its twin-appears as greenish star.

REVOLUTION : 165 yrs , ROTATION : 15.7 DAYS.It discovered by JG Galle of berlin in 1846. Neptune was the first planet found by mathematical prediction rather than by empirical observation. Has 13 satellites prominent are Triton and Nereid.Neptune is surrounded by methene rings of subzero temperature.

PLUTO

PLUTO :  On the basic of the law definition of planet given by the IAU, the world's top institution on space science research, leading astronomers participating in IAU' meet at prague on august 24, 2006, declared that pluto would no longer remain a planet .PLuto is the second largest know dwarf planet in the solar system. Weeks after it was demoted to a subplanetar status, pluto was given a new name to reflect its new status as a dwarf planet in semtember 2006.The former 9th planet was assigned the asteroid number 134340 by the minor planet centre, the official organisation responsible for collecting data about asteroids and comets in our solar system.  pluto's companion satellites, charon, nix and hydra are considered part of the same system and will not be assigned separate asteroid numbers. Instead, they will now be called 134340 1,11,111 respectively. Before loosing its planetary status on 24th august, 2006, pluto was the outermost planet of the solar system.

MOON

MOON : The moon is the only natural satellite of the earth ,and the fifth largest satellite in the solar system.It is the largest natural satellite of a planet in the solar system relative to the size  of its primary, having a quarter the diameter of earth and 1/81 its mass.Moon is the second largest satellite after Io, a satellite of jupiter .circumference of moon is 11,000 km.,diameter is 3475km ,gravitational pull is 1/6th of earth. Its orbit around earth is elliptical.The maximum distance of the moon from the earth is 406,000 km and the minimum distance is 364,000 km.The average distance is 3,82,200 km.takes 27 days,7 hours, 43 min and 11.47 sec to complete one revolution around earth.Rotates on its axis in exactly the same time as it takes to complete one revolution.That is why we see only one side of the moon.To our unaided vision, moon seems to be made-up of bright and dak patches.The bright parts are the mountains and highlands,while the darker patches are low-lying planes.The highest mountains, which are 10,660 m high.They are situated at moon's south pole.Moon has no atmosphere, no twilight and no sound . Moonlight takes 1.3 sec to reach earth .It has low albedo .It reflects only 7% and the rest is absorbed. NEIL AMSTRONG and BUZZ ALDRIN reached moon on july 21, 1969 .The moon is the only celestial body other  than earth on which humans have set foot.While the union's luna programme was the first to reach the moon with  unmanned space craft in 1959, the united states nasa apolo program achieved the only manned mission to date ,begining with the first manned lunar orbiting mission by apollo 8 in1968, and six manned lunar landings between 1969 and 1972 , with the first being apollo 11. These missions returned over 380 kg of lunar rocks, which have been used to develop geological understanding of the moon's origins, the formation of its internal structure, and its subsequent history .It is thought to have formed some 4.5 billion years ago.After the apollo 17 mission in 1972 , the moon has been visited only by unmanned spacecraft , notably by the final soviet lunokhod  rover .since 2004, japan ,china, india , the united states, and the european space agency have each sent lunar orbiters.These spacecraft have contributed to confirming the discovery of lunar water ice in permanently shadowed craters at the poles and bound into the lunar regolith .Future manned missions to the moon have been planed,including government
as well as privately funded efforts .The moon remains,under the outer space treaty, free to all nations to explore for peaceful purposes.

SUN

THE SUN :It is one of the stars in the milky way galaxy. It takes 224 million years to complete one circle (Revolution ) around the galactric circle called Cosmic year.The sun is 109 times bigger than the earth and weights we see , is called photosphere. Above the photosphere is the chromosphere .Beyond chromosphere is the chromosphere is the corona which is visible during eclipses.The core of the sun has the temperature about 15 million degrees k. The sun is at the centre of the solar system and all this bodies are revolving around it.Its size is Thirteen lakh times as that of the Earth it is the nearest Star to the Earth.It is an ultimate source of energy for life on earth.its diameter is 14 lakh kms. it is composed of 71% hydrogen,26.5 helium and elemants. Hydrogen and helium are the main gases present in the sun .Within the sun,hydrogen is converted to helium due to nuclear fusion releasing a tremendous amount of heat and light.It has a surface temperature of about 6000 degree centigrade, the temperature at the centre is around 15,000000 degree centigrade.The sun constantly emitting streams of its substance as protons in all directions.Sometimes these emissions are massive.Such emissions are called prominences.Sometimes these emissions roll out of the atmosphere of the sun for thousands and thousands of miles, when they are seen as solar flares. A persistent stream of protons and electrons is blowing out of the corona and sweeping over the whole solar system.This stream is called solar wind.The earth's magnetosphere acts as a shield against the ever -blowing solar wind and deflects it away from the earth. Nevertheless ,particles of solar wind sometimes piercethe magnetic shield and enter the upper atmosphere, where, like the solar flares,theycause auroral displays.In the artic region, they are called aurora borealis and in the antarctic region, they are known as aurora australis.The surface of the sun changes continuously.Bright spots called plages and dark spots called sunsports occurthere. Sunspots appear dark because they are cooler,ie, they have a temperature of about 1500 degree c.Sunspots have a periodicity of 11 years.The energy of sun comes from the fusion of hydrogen into helium.Sunlight takes eight min,16.6 sec to reach earth.Ecliptic is an imaginary annual path of sun across the sky.It age is 5 billion years and the total life is ten billion years.                                                                                      

Some important question and answer of planets                                                                                                 

QUE 1 : What is the hottest planet  in our solar system ?

ANS    :  Venus.      

QUE 2 : What is the closest planet to the sun ?

ANS    :  Mercury.

QUE 3 : What is the smallest planet in our solar system ?

ANS    :   Mercury.

QUE 4 : What is the biggest planet in our solar system ?

ANS    :   Jupiter.

QUE 5 : What is the coldest planet in our solar system ?

ANS    :  Neptune.

QUE 6 : What is the name of the 2nd biggest planet in our solar system ?

ANS    :  Saturn.

QUE 7 : What planet is famous for its big red spot on it ?

ANS    :  Jupiter.

QUE 8 : What planet is famous for the beautiful rings that surrounded it ?

ANS     : Saturn.

QUE 9 : What planet is know as the red planet ?

ANS    :  Marsh.

QUE 10 : Earth is located in which galaxy ?

ANS       :  The milky way galaxy 15. sputnik.

QUE 11 : Phobos and Deimos are two satellite of which planet ?

ANS      :  Mars.

QUE 12 : What is the name of the first satellite sent into the space  ?
ANS      :  Sputnik.
QUE 13 : Titan is a satellite of which planet ?
ANS       :  Saturn.
QUE 14 : What is the name of Nasa's most famous space telescope ?
ANS       : Humble space telescope.
QUE 15 : Which satellite is the Biggest satellite ?
ANS       : Gannymede.
QUE 16 : Which satellite is the Smallest satellite ?
ANS      : Deimos.
QUE 17 :Which planet is called Blue planet ?
ANS       : Earth.
QUE 18 : Which planet is called Moring star ?
ANS       : Venus.
QUE 19 :Which planet is called Green planet ?
ANS       : Neptune.
QUE 20  :Which planet is called Evenin star ?
ANS        : Venus.
QUE 21 : Which planet is called earth's twin ?
ANS       : Venus.
QUE 22 : Which planet is the called lord of heavens ?
ANS       : Jupiter.
QUE 23 : Which planet is the heaviest planet ?
ANS        : Jupiter.
QUE 24  : Which planet is the hottest planet ?
ANS        :Venus.
QUE 25  :Which planet has maximum satellite ?
ANS        : Jupiter.
QUE 26  :Which star is brightest star after the sun ?
ANS        : Sirius.
QUE 27  : Which planet is the nearest planet to  earth ?
ANS        : Venus.
QUE 28 :  Which planet is the farthest planet from sun ?
ANS        : Neptune.
QUE 29 :  Which is called Dog star ?
ANS        :Sirius.