Sun’s family is known as solar system. The major objects that form the solar system are Comets, Meteors, Sun, satellites (or moons), nine planets and asteroids. We will discuss all the components in detail. Let us first discuss about the sun which is the major part of solar system.
1. Sun: The brightest star of our solar system is sun. The approximate diameter and mass of sun is approximately 1.392 X 109m and 1.98 X 1030kg respectively. The sun is 109 times bigger than that of earth.
Earth and sun have an average distance of near about 1.496 X 10 11m. This distance can be called as1 Astronomical unit. Basically two types of rotations are there one is rotation around some other body and other is rotation around own axis. For a complete rotation around its axis sun needs 25 days. As we all know it is a ball of heat and gases. So there is no need to explain that the temperature and pressure inside the sun are extremely high. By conducting experiments the approximately calculated temperature on the surface of sun is near about 6000k. The light from the sun reach at the earth surface in near about 8.3 minutes.
2. Planets: The heavenly body which doesn’t have light of its own. These bodies revolve around the sun. They have the capability to reflect the light of sun that falls on them. Nine planets are present in our solar system. All of these are rotating in different orbital around the sun and also on their own axis.
Ordered list of all these planets is given below:
Mercury: The planet nearest to sun is mercury. Its radius and mass are 2410km and 3.35 X 1023 respectively. Time taken by it to complete one revolution around sun is 88 days. Due to high temperature on the planet no water is present their. Hence occurrence of life on mercury is impossible.
Venus: The planet present after mercury in sequence is Venus. This planet is similar to that of earth. Its density, radius, mass etc are approximately similar. Due to its similarities it is also known as ‘Earth’s sister’. The percent of carbon dioxide on Venus is extremely large as compared to that of other gases. 95% composition is of Carbon Dioxide and 5% composition is of the other gases. Force exerting per unit area on Venus is approximately 100 times more than that of earth. Temperature present on the surface of Venus is also very high as compared to earth. It is near about 450oC. Due to such high temperature the life on Venus is also not possible. It takes about 225 days to complete its one revolution around the sun. It is also known as morning star. It is called so because it is the brightest planet in the solar system. It does not have any satellite of its own.
Earth: Starting from the sun and moving towards Pluto it is the third planet. It takes near about 365.25 days to complete one revolution around the sun. After the passage of four years we get a leap year because the rotation time .25 after four years (.25+.25+.25+.25=1day) becomes 1 .So, one day is increased after 4 years. In a leap year rather than having 365 days we have 366 days. Atmospheric conditions are suitable for life that’s why we are living on earth. Water is also present in plenty.
Mars: Planet next to earth is mars. Its radius is about 3400km. It takes near about 1.9 years to complete its one revolution around the sun. Like Venus carbon dioxide gas is present here in plenty. But atmosphere is not so thick like other planets. Some patches are present on its surface. They contract and expand according to the environmental conditions. Mostly expansion can be seen in winters and contraction can be seen in summers. It’s like chameleon which changes color as the season changes. Yet no life has been founded on mars. Mars is also called as the red planet of the solar system. Fobos and Dimos are the names of its two moons.
Remaining planets: As we go farther from the sun the atmospheric temperature goes on decreasing. So, on the other planets the temperature on their surfaces is low. On the remaining planets most of the poisonous gases like methane, ammonia etc can be found. Due to these poisonous gases no occurrence of life can be seen there.
Moon: Earth has only one natural satellite i.e. Moon. Moon is present at a distance of near about 3.84 X 10 5. Radius of moon is about 1740km. Total mass of moon is 7.35 X 10 22. The gravitational pull of moon is 1/6 then the gravitational pull of earth. Moon completes its one revolution around the earth in 27.3days. It is also called ‘Radio moon’ because it has the capability of emitting of electromagnetic waves in radio wave region. Moon face that is towards earth remains always the same. Temperature ranges of moon in day time and at night are 110oc and -150oc. Both water and atmospheric conditions are absent on moons surface. Earlier it was said that there was no water and atmosphere present on the moons surface. But Scientists have found some evidences of water molecules on the moons surface. So, we can say that at some later stage their may be the possibility of life on moons surface. According to the estimations, it is said that age of moon is near about four billion years.
Asteroids: This is an area also we can say it as a belt between mars and Jupiter in which large no of bodies having irregular shapes are present. These bodies are called asteroids. These are large no of rock pieces moving at higher speed between both mars and Jupiter and around the sun. The largest asteroid is Ceres. It is about 350km.The smallest asteroid of all is having a radius of near about 50m. It is supposed that these rock pieces are the broken pieces of any large planet, which were broken due to the string gravitational pull of the planet Jupiter. The asteroids which is larger in size, completes its one revolution around sun in approximately 4.6 years.
Comets: Comets are heavenly bodies made up of hard and soft rocks mostly covered with substances that can be changed into vapors easily like water, ice methane etc. Their revolution around sun is in fixed orbits. When the comets are passing near to the sun they show a long tail behind them with a bright head. On the other hand when the comets are far from the sun then their tail disappears.
When the comets came near to sun then due to the extreme hot temperature of sun some of the material present in the comet gets evaporated. The vapors of comet feel great pressure due to sun light. The light of the sun also compel them to leave the comet. This process helps in formation of tail of the comet.
Halley comet completes its one revolution around the sun in 76 years. Last it was seen in the year 1986. Now it is expected that we will able to see it again in the year 2062.
Meteors: Due to the damage of the comets some small pieces of metals and rocks are formed. These are called Meteors. But these cases are very rare. As we know that friction is present in our atmosphere. It is due to the presence of air and the gravitational pull of earth. As the meteors enter the region of earth’s gravitational pull these are burnt out due to the friction. When the meteors catch fire then the bright light is produced. The light produced can be seen easily from the earth’s surface. These luminous meteors are called as fire balls or shooting stars. Meteors can be of any size. Some large meteors, after entering the earth’s atmosphere did not burn completely. Then those meteors reach the earth’s surface in state of stones, iron balls, etc and cause destruction in the form of large craters.
The table given below is showing the detailed information of all the planets.
|S:no||Name of Planet||Radius R X 103||Mass as compared to earth||Mean distance from sum X 10 6||Time of revolution around sun||No of satellites||Time taken to complete one revolution around their own axis|
|1.||Mercury||2.4||.055||57.9||88 days||-||59 days|
|2.||Venus||6.1||.815||108.2||225 days||-||243 days|
|3.||Earth||6.3||1||149.6||1 Year||1||23 hrs 56 kin|
|4.||Mars||3.4||.108||227.9||1.9 Year||2||24 hrs 27 min|
|5.||Jupiter||71.4||317.9||778.3||11.8 Year||14||9 hrs 50 min|
|6.||Saturn||60.0||95.2||1427||29.5 Year||10+Ring||10 hrs 14 min|
|7.||Uranus||23.4||14.6||2870||85 Year||5+Ring||10 hrs 49 min|
|8.||Neptune||22.3||17.2||4594||165 Year||2||15 hrs|
|9.||Pluto||3.2||.002||5900||248 Year||-||6.39 days|