1. 2. THE SOLAR SYSTEM [Section 2] Topics CoveredSlide Numbers 2 Origin [2 ] 2.1 Age[3] 2.2Characteristics[4-22] Published by Pearson Education India Authored by Edgar Thorpe & Showick Thorpe

2. Question 1: First scientific system regarding the origin of solar system was put forward by whom? Answer: Marquis de Laplace (France) in 1796. Extra Fact Punch He propounded a theory: the sun is spinning rapidly as it contracted after its birth, threw off from its centre, rings of the gaseous material, each of which condensed into a separate planet.

3. Question 2: We know that the Solar system formed 4,600 million years ago. By which method was the age of solar system confirmed? Answer: Radioactive decay. Extra Fact Punch By measuring such decay in meteorites, scientists learned that the Sun and the planets formed 4600 million years ago. This was confirmed by the study of moon rocks.

4. Question 6: Objects found further than the most distant planet in our solar system, Pluto are? Answer: Varuna(2000), Ixion(2001), Quaoar(2002), and Sedna(2003). Extra Fact Punch The nearest star is about 9,000 times farther away than most distant planet in our solar system.

5. Question 8: Pluto is considered as dwarf planet and was discovered by? Answer: Clyde Tombaugh in 1930. Extra Fact Punch It is now classified as a dwarf planet along with Ceres and Eris.

6. Question 9: Arrange different layers of Sun moving from the innermost to the outermost layer. Answer: Corona, Chromosphere, Photosphere. Extra Fact Punch Glowing surface is called the photosphere. Above the photosphere is the chromosphere, and beyond this layer is the corona which is visible during eclipses.

7. Question 12: Is it possible to view Sun’s layer during total solar eclipse? If yes name the different layers. Answer: The Chromosphere and corona. Extra Fact Punch The chromosphere appears as a pinkish-violet layer with occasional prominence.

8. Question 14:_____ are dark irregular shaped regions with diameters extending to tens of thousands of miles. Answer: Sunspots. Extra Fact Punch The astronomers believe that sunspots occur when lines of magnetic forces break through the sun’s surface..

9. Question 19: Sunspots group have an average life of _____. Answer: From 2 to 3 weeks. Extra Fact Punch But some sunspots group have lasted for more than a year. The record duration of the sunspot is 8 years.

10. Question 24: When did the Viking-1 and Viking-2 spacecrafts land on mars to study the existence of life on the Planet? Answer: Viking-1, landed on mars in July 1979 and Vikings-2 in September1979. Extra Fact Punch The experiments revealed no traces of life.

11. Question 26: ______is the largest satellite in our solar system. Answer: Ganymede. Extra Fact Punch Ganymede is a prominent satellite of Jupiter along with Europa and Callisto.

12. Question 27: ____is the biggest satellite of the planet with ring system? Answer: Titan. Extra Fact Punch Saturn is outer planet visible to naked eye. Ring system is made up of a variety of separate particles which move independently in circular orbits..

13. Question 28: Uranus is the first planet discovered through Telescope. Who discovered it? Answer: William Herchel in 1781. Extra Fact Punch The most prominent satellite of Uranus are Miranda, Ariel, Umbriel and Titanis.

14. Question 29: Neptune was discovered by? Answer: J.G Galle of Berlin in 1846. Extra Fact Punch Major satellites are Triton and Nereid.

15. Question 31: Moon takes ____days, _____hours,____ minutes and _____ seconds to complete one revolution of the earth? Answer: 27 days 7 hours 43 minutes and 11.47 seconds. Extra Fact Punch It takes 1.3 seconds for moonlight to reach the earth, whereas sunlight takes about 8 minutes and 16.6 seconds to reach the Earth.

16. Question 32: Neil Armstrong and Edwin Aldrin first stepped on the surface of moon on July 21,1969? True or False. If true then name the spacecraft? Answer: Apollo 11. Extra Fact Punch A total of 12 Americans walked on the surface of the Moon during Apollo programme.

17. Question 33: Asteroids are also known as _______. Answer: Planetoids. Extra Fact Punch The first ten minor planets include: Ceres, Pallas, June, Vesta, Astraea, Heba. There are about 50,000 known asteroids in our solar system.

18. Question 35: The word ‘Comet’ is derived from Greek letter ‘Kometes’ what does ‘Kometes’ mean? Answer: Kometes means ‘hair –like’. Extra Fact Punch There are about 1,00,000 comets in our solar system.

19. Question 36: Halley’s comet is named after Edmund Halley. When did it last appear? Answer: It last appeared in 1896. Extra Fact Punch Halley stated that the comets were seen in 1531,1607 and 1682 ad it may reappear after 76 years.

20. Question 37: When is Comet ‘Smith-Tuttle’ likely to collide with the earth? Answer: On August17, 2116. Extra Fact Punch Smith Tuttle was first sighted in 1862. it travels at a speed of 60 km/sec.

21. Question 38: When and by whom was comet ‘Shoemaker Levy-9’ discovered? Answer: it was discovered on March 24,1993. By Scientists (a) Carolyn (b) Eugene Shoemaker (c) David Levy. Extra Fact Punch Comet was around 6 miles long and weighted about 500 billion tonnes.

22. Question 39: ‘Aurora Borealis’ is also known as? Answer: Northern lights. Extra Fact Punch The luminous occurrences in high altitudes of both hemispheres are called ‘Aurora Borealis’ or ‘northern lights’ in the northern hemisphere, and ‘Aurora Australis’ in the southern hemisphere.