Social Studies is an important section for CTET, MPTET, State TET, and other teaching exams as well. Social studies is the main subject in the CTET exam Paper II. In CTET Exam, the Social Studies section comprises a total 60 questions of 60 marks, in which 40 questions come from the content section i.e.History, Geography and Political Science and the rest 20 questions from Social Studies Pedagogy section.
At least 10-15 questions are asked from the Geography section in the CTET Social studies section. Here we are providing important facts related to the Solar System.
All planets of our solar system can be categorised into two types, namely rocky (terrestrial) and gaseous planets. Rocky planets include Mercury, Earth, Venus, and Mars. Whereas gaseous planets include Jupiter, Uranus, Saturn, and Neptune, in which Jupiter and Saturn carries highest amount of hydrogen and helium. There are four planets that have rings around them and these are Jupiter, Uranus, Saturn, and Neptune. In our solar system, the entire planets orbit around the sun. Neptune is the outermost planet that orbits and revolves around 30 astronomical units from the sun. astronomical unit is calculated as follows:
an astronomical unit = Distance between Sun and Earth (149 million km)
The galaxy that we live in is named as ‘Milky Way’, and it has many planets of different nature, shape, and size.
It is the nearest planet to the sun. it is the smallest planet in our galaxy and has no satellite.
- It has a magnetic field
- It has lesser density, even less than water
- It has extremely hot days and very cool nights.
- It has temperature difference of approximate 560°C.
It is the nearest planet of earth. It is also known as the evening star and morning star. It revolves clockwise, which is different from other planets, as they revolve anticlockwise. It does not have any satellite.
It is also known as red planet, as it is red in colour. It has two poles like earth, that is, North Pole and South Pole. It completes a circuit on its axis in 24 hours, it takes 687 days to complete one circumambulation of Sun, where for Earth it is 365 days and it is called a year.
It is the largest planet of the solar system. It takes 10 hours to rotate on its axis, it takes 12 years to complete one circumambulation of Sun.
It is the second largest planet of the solar system. It has seven bracelets around it. The biggest satellite of this planet is Titan,
It is the third largest planet of the solar system. It was discovered by William Herschel in the year 1781. It rotates form east to west on its axis. The biggest satellite of this planet is Titania.
It was discovered in 1846 by German astronomer Johann Galle. Cold methane cloud rotates around it. It has more than one satellite, among them satellite Triton is important. It is 17 times larger than the earth.
The nearest star of Earth is Proxima Centauri,
Shape and Size of Earth
It is oblate spheroid in shape. The diameter of earth on equator is approximately 12,762 km, the polar diameter is of 12,713 km.
Moon is the satellite of Earth. It rotates on its axis along with its rotation on the orbit round the Earth. Its axis makes an angle of 58.48° with the axis of earth. It has a radius of 3480 km, and its mass is 1/8 of the earth. During the rotation, when it is closer to the earth, it is known as perigee, when it is farthest, distance of 407,00 km.
Between the orbits of Mars and Jupiter, there are small celestial bodies that rotate around the sun, and these are called asteroids. Sometimes these asteroids come into the atmosphere of earth and collide with its surface forming big digs or pits. One such example is Lonar Lake in Maharashtra.
Asteroids can be categorised into three types. First is Type-C (carbonaceous). These are greyish in colour. These are made up of clay and stones. Type-S (silicaneous) asteroids are greenish and reddish in colour. These are made up of nickel iron and silicate materials. Type-M is reddish in colour. These are also known as metallic asteroids.
There are millions of heavy bodies on the exteriors of solar system, which are called comets. The rotational time of the comet is called Halley, which is 76 years. Last time, it was seen in the year 1886 and in the year 1962.