Chapter 12 Celestial Bodies and Indian Calendar

RBSE Solutions for Class 9 Science Chapter 12 Celestial Bodies and Indian Calendar

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Rajasthan Board RBSE Class 9 Science Chapter 12 Celestial Bodies and Indian Calendar

Celestial Bodies and Indian Calendar Textbook Questions Solved

Objective Type Questions

Question 1.
Celestial bodies which have their own light and heat are known as:
(A) Stars
(B) Planets
(C) Satellites
(D) Meteors
Answer: A

Question 2.
Moon is categorised in which series of solar system?
(A) Star                      ”
(B) Planet              ”
(C) Satellite
(D) Asteroid
Answer: C

Question 3.
According to Indian Panchang, the number of Nakshatra are:
(A) 15
(B) 27
(C) 12
(D) 07
Answer: B

Question 4.
According to Indian Panchang the number of Rashis are:
(A) 15
(B) 27
(C) 12
(D) 07
Answer: C

Question 5.
Which is the largest body in our Solar System?
(A) Jupiter
(B) Sun
(C) Earth
(D) Saturn
Answer: B

Question 6.
Which is the largest planet in our Solar System:
(A) Jupiter
(B) Saturn
(C) Uranus
(D) Naptune
Answer: A

Question 7.
After how many years did Adhik Mass occurs?
(A) After 1 year
(B) After 2 years
(C) After 3 years
(D) After 4 years
Answer: B

Question 8.
In which Rashi, Sun is located after starting of Dakshinayan?
(A) Cancer
(B) Leo
(C) Capricorn
(D) Aquarius
Answer: A

Celestial Bodies and Indian Calendar Very Short Answer Type Questions

Question 9.
Who wrote the book Lilawati based on Arithmetic?
Answer
Bhaskaracharya.

Question 10.
The first Indian Satellite was named on which scientist?
Answer
Aryabhatta.

Question 11.
Which the occurs after chaturdashi of Shukla paksh?
Answer
Panchami.

Question 12.
Name the Chandramass in which moon is at Mrigashira Nakshatra on Pumima.
Answer
Marga Shirsh.

Question 13.
Which planet has the least orbital time period?
Answer
Mercury. Its orbital time period is 88 days.

Question 14.
Write the name of the planet in serial order on the basis of their distance from the Sun?
Answer
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Question 15.
Write the name of ‘terrestrial planets’?
Answer
Terrestrial planets are – Mercury, Venus, Earth, Mars.

Question 16.
Life is discovered on which planet, except Earth?
Answer
Mars.

Question 17.
Name the shadow planets according to Indian Panchang?
Answer
The shadow planets according to Indian Panchang are Rahu and Ketu.

Question 18.
Two Planets A and B are simultaneously a distance X and Y from Sun. IfYis greater than X, then which planet has the largest revolution time.
Answer
Y is greater than X, so Y has the larger revolution time.

Celestial Bodies and Indian Calendar Short Answer type Questions

Question 19.
Name the planets in series according to their distance from Earth?
Answer
Venus, Mars, Mercury, Jupiter Saturn, Uranus, Neptune.

Question 20.
Name the main five and of Indian Panchang?
Answer
A Hindu muhurta (forty-eight-minute duration) can be represented in five attributes of Hindu astronomy, namely, vara the weekday, tithi, nakshatra the Moon’s asterism, yoga. The angular relationship between Sun and Moon and /carana-half of a tithi.

Question 21.
What do you mean by nakshatra? It is divided in how many parts? Name any five nakshatras?
Answer
Nakshatra
Nakshatras are considered to be the lunar mansions seen higher up in the sky, which creates a huge impression on the people and impact their lives as well as behaviour. Vedic astrology divides nakshatra into 27 parts and each part has its unique name.
They are:

Name	No. of Stars in group
Ashvini	03
Bharani	03
Krithika	06
Rohini	05
Mrigashirsha	03

Question 22.
Explain in brief how do you specify tithi on the basis of Indian Panchang?
Answer
Tithis: In Vedic timekeeping, a tithi (also spelled thithij is a lunar day or the time it takes for the longitudinal angle between the Moon and the Sun to increase by 12°.
Tithis begin at varying times of day and vary in duration from 19 to approximately 26 hours. Thithi plays an important role along with nakshatra in Hindu’s daily as well as special activities, in selecting the muhurta. There are good tithis, as well as bad tithis.

The good tithis are called shulkla paksha (bright fortnight) and the bad tithis are called Krishna Paksha (dark fortnight), when fast moving moon gives an interval of 12° from Sun, then that time interval is called Pratipada Tithi.

Question 23.
Write the name of planets according to their size?
Answer
Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, Jupiter.

Question 24.
Explain the Uttarayan and Dakshinayan.
Answer
Uttarayan- Dakshinayan

• Uttarayan- After 22 December, the Sunrise gradually shifts towards east. This continues till 21 June. It is the period between the makar Sankranti and karka Sankranti. Uttarayan means north movement. This is the six month period which indicates a semantic of the northward movement of the Sun on the celestial hemisphere. In this period days are bigger than night.
• Dakshinayan: The summer solstice occurs around 21 June. So, from 21 June, the Sunrise gradually shifts towards the south. This continues till 22 December. According to Indian Astronomy, in this period the Sunrise is said to be dakshinayan, moving towards the south. It is the period between karka Sankranti and Makar Sankranti. In this period days are shorter than night.

Question 25.
Explain the different motion of the Earth.
Answer
The motion of the Earth around the Sun is called a revolution. It revolves around the sun at a distance of 150000000 km (app.) in a nearly circular orbit. It takes 365.25 days to complete one revolution around the Sun. Earth spins about its own imaginary axis like a top, from west to east. This motion of the Earth about its own axis, is called rotation. Earth completes one rotation about its own axis in 24 hours. Days and nights are formed due to the rotation of Earth about its own axis, in 24 hours. Seasons are caused due to the revolution of Earth around the Sun and the tilting of its axis of rotation.

Question 26.
According to Indian Panchang, what type of motion is related to Rashi? How Rashis are specified?
Answer
Rashi: Moon sign at the time of the birth is known as Rashi. Moon sign is the name of the zodiac in which the moon was located at the time of the birth are affected due to the revolution of Earth around the Sun, as well as the by the preception of Sun moving along elliptical path along the space occupied by 12 reshis and 27 nakrashtra (or constellations).

Question 27.
What do you mean by Makar Sankranti?
Answer
When the earth moves from one Rashi to another Rashi, it is called Sankaranti. Makar Sankranti marks the transition of the Sun into the zodiacal sign of Makra (Capricorn) on its celestial path.

Question 28.
What do you understand by Adhika Mass?
Answer
In 2018, there is an extra month or Adhika mass as per the Hindu calendar. This month is also known as the Mai Mass or Londa Mass or Purushottam Mass. The Adhika mass starts from May 16, 2018 and ends on June 13, 2018 and is dedicated to Lord Shri Krishna. The position of this month in the Hindu calendar is not fixed and it can occur between any two months, randomly. The Radhika mass is added to the Lunar calendar, to compensate for the extra days of the lunar and solar calendars.

Question 29.
Explain the Transit of Mercury and compare it with Transit of Venus?
Answer
A transit of Mercury across the Sun takes place, when the planet Mercury passes directly between the Sun and a superior planet, becoming visible against the solar disk. During a transit, Mercury can be seen from Earth as a small black disk moving across the face of the Sun. The duration of such transits is usually measured in hours (the transit of 2012 lasted 6 hours and 40 minutes).

Comparison between Transit of Mercury and Transit of Venus:During a transit, Mercury can be seen as a very small black disk moving across the face of the Sun. Transits of Mercury with respect of Earth are much more frequent than transits of Venus, with about 13 or 14 per century, in part because Mercury is closer to the Sun and orbits it more rapidly. Transits of Mercury occur in May or November. The last four transits occurred on November 15, 1999; May 7, 2003; November 8, 2006 and May 9, 2016 and the transit of Venus took place on 8, June 2004. The next transit of Venus will be on 10-11, December 2117 and 9 December 2115 and the next transit of Mercury will occur on November 11, 2019, and then on November 13, 2032.

Question 30.
Write the Solar months name according to Indian Panchang?
Answer
Solar month name:Vaisakha
Jyaistha
Aashaadha
Sraavana
Bhaadrapada
Asvayuja(Aasvina)
Kaarthika
Maarghasira
Pausa (Pushyam)
Maagha
Phalguna
Chaitra

Celestial Bodies and Indian Calendar Long Answer Type Questions

Question 31.
Write the biography of Aryabhatta and describe their main scientific works in detail?
Answer
Aryabhatta: Aryabhatta was an acclaimed mathematician astronomer. He was born in Kusumapura (Patna) in Bihar, India. His contribution to mathematics, Science and astronomy is immense and yet he has not been accorded the recognition in the world history of science. At the age of 24, he wrote his famed “Aryabhatiya”. He was aware of the concept of zero, as well as the use of large numbers up to 1018. He was the first to calculate the value for ‘pi’ accurately, to the fourth decimal point. He devised the formula for calculating areas of triangles and circles. He calculated the circumference of the earth as 62832 miles, which is an excellent approximation, and suggested that the apparent rotation of the heavens was due to the axial rotation of the earth on its axis.

He was the first known astronomer to devise a continuous counting of solar days, designating each day with a number. He asserted that the planets shine, due to the reflection of sunlight, and that eclipses occur due to the shadows of the moon and earth. His observations account for the ‘flat earth concept and lay the foundation for the belief that earth and other planets orbit the Sun.

Scientific works and achievements:

Direct details of his work are known only from the Aryabhatiya, His disciple Bhaskara I, calls it Ashmakatantra (or the treatise from the Ashmaka). The Aryabhatiya is also occasionally referred to as Arya-shatas-ashta (literally, Aryabhata’s 108), because there are 108 verses in the text. It also has 13 introductory verses, and is divided into four or chapters.

Aryabhatiya’s  first chapter, Gitikapada, with its large units of timc-Kalpa, manvantra, and Yuga-introduces a different cosmology. The duration of the planetary revolutions during a mahayuga is given as 4.32 million years.

Ganitapada, the second chapter of Aryabhatiya has 33 verses, covering mensuration, arithmetic and geometric progressions, gnomon or shadows, simple, quadratic, simultaneous, and indeterminate equations. Aiyabhatiya’s third chapter, Kalakriyapada explains different units of time, a method for determining the positions of planets for a given day, and a seven – day week with names for the days of week.

The last chapter of the Aryabhatiya, Golapada describes Geometric/ trigonometric aspects of the celestial sphere, features of the ecliptic, celestial equator, shape of the earth, cause of day and night and zodiacal signs on the horizon.

• It is speculated that Aryabhata used the word (approaching), to mean that not only is this an approximation but that the value is incommensurable or irrational.
• In Ganitapada, he gives the area of a triangle as: “for a triangle, the result of a perpendicular with the half-side is the area. He discussed sine, by the name of ardha-jya or half-chord.
• Like other ancient Indian mathematicians, he too was interested in finding integer solutions to Diophantine equations, with the form – + by = c; he called it the (meaning breaking into pieces) method.
• His contribution to the study of Algebra is immense. In Aryabhatiya, Aryabhata provided elegant results for the summation of series of squares and cubes through well-tried formulae.
• He correctly believed that the earth rotates about its axis daily.
• In Aryabhatiya, he writes that ‘setting and rising of planets’ is a perception, similar to that of Someone in a boat going forward sees an object going backwards.
• He correctly, asserted that the planets shine, due to the reflection of sunlight, and that the eclipses occur due to the shadows of moon and earth, and not caused by a demon called ‘Rahu’.
• He correctly deduced that the orbits of the planets are ellipses.

Other Achievements:

The gave the knowledge of Algebra, Intermediate equations, Trigonometry, Place value system and zero and also the motions of the Solar system.

Question 32.
Write the biography of Bhaskaracharya? and describe their main scientific works in detail?
Answer
Bhaskara was born in 1114, near Vijjadavida (believed to be Bijjaragi of Vijayapur in modern Karnataka).
Bhaskara II, also known as Bhaskara or as Bhaskaracharya, was a 12th-century Indian mathematician. He was also a renowned astronomer, who accurately defined many astronomical quantities, including the length of the sidereal year. A brilliant mathematician, he made the significant discovery of the principles of differential calculus and its application to astronomical problems and computations centuries before European mathematicians, like Newton and Leibniz made similar discoveries.

It is believed that Bhaskara II was the first to conceive the differential coefficient and differential calculus. Bhaskara II wrote the first work with full and systematic use of the decimal number system and also wrote extensively on other mathematical techniques and on his astronomical observations of planetary positions, conjunctions, eclipses, cosmography, and geography. In addition, he also filled many of the gaps, in his predecessor, Brahmagupta’s work. In recognition of his invaluable contributions, to mathematics and astronomy, he has been called the greatest mathematician of medieval India.
Scientific work and achievements:
1. He made many significant contributions to mathematics, throughout his career. He is credited to have given a proof of the Pythagorean theorem, by calculating the same area in two different ways, and then cancelling out terms, to get a2 + b2 = c2 .

2. His work on calculus was groundbreaking and much ahead of his times. He not only discovered the principles of differential calculus and its application to astronomical problems and computations but also determined solutions of linear and quadratic indeterminate equations (Kuttaka). The works in calculus performed by the European mathematicians of the 17th century is comparable to the rules he had discovered, way back in the 12th century.

3. His major work ‘Siddhanta Siromani’(“Crown of treatises”) was completed in 1150 when he was 36 years old. Composed in the Sanskrit Language, the treatise consists of 1450 verses. The work is divided into four parts called “Lilavati, “Bijaganita’, and ‘Goladhyaya’, which are also sometimes considered four independent works. The different sections deal with different mathematical and astronomical fields.

4. The first part “Lilavati’ consists of 13 chapters, mainly definitions, arithmetical terms, interest computation, arithmetical and geometrical progressions, plane geometry and solid geometry and many others aspects of mathematics. It also has a number of methods for computing numbers, such as multiplication, squares, and progression.

5. His work “Bijaganita’(“Algebra”) was a work in 12 chapters. This book covered topics like positive and negative numbers, zero, surds, determining unknown quantities, and elaborated the method of ‘Kuttaka’for solving indeterminate equations and Diophantine equations. He also filled many of the gaps in his predecessor, Brahmagupta’s work.

6. The sections ‘Ganitadhyaya’ and ‘Goladhyaya’ of ‘Siddhanta Shiromani ’ are devoted to astronomy. He used an astronomical model developed by Brahmagupta, to accurately define many astronomical quantities, including the length of the sidereal year. These sections covered topics such as mean longitudes of the planets, true longitudes of the planets, solar and lunar eclipses, cosmography, geography etc.

7. Bhaskara II was especially known for his in-depth knowledge of trigonometry Discoveries first found in his works, including computation of sine of angles of 18 and 36 degrees. He is credited to have discovered spherical trigonometry, a branch of spherical geometry, which is of great importance for calculations, in astronomy, geodesy and navigation.

8. Bhaskara-II major work was the treatise-‘Siddhanta Siromani’, which was further divided into four parts, each of them dealing with diverse topics on arithmetic, algebra, calculus, trigonometry, and astronomy. He is considered to be a pioneer in the field of calculus, as it is probable that he was the first to conceive the differential coefficient and differential calculus.

Question 33.
What is the base of naming the Indian months? Write the name of the Indian months and describe their position in the sky at that time.
Answer
The complexity of the Indian calendar system is not just in the plethora of available calendar, but also in the manner in which they link up with one another. A principal point of linkage of most Indian calendars is their name of the months, As we shall see, the similar set of month names are used in more than one calendar. We aim to formulate the rules, determining the name of months. Our motivation is not just taxonomic, month names, as we shall see, are critical for understanding the Indian calendar system.

The set of month names named after nakshatras is used by both solar and lunisolar calendars, adding to the complexity of the Indian calendar system. Indeed, as we shall see, this type should actually called months initially named after nakshatras; there has been an infusion of solar rules into an essentially lunar convention. The motion of the moon is related to lunar months.

Let us then, first consider the original rule. Saha and Lahiri mention that Pakshas or fortnights were differentiated based on the nakshatra. That is to say, if a particular full moon occurs near, say, the lunar asterism, Visakha, the full moon would be called as Vaisakha Pumimasi, and the month would be Vaisakha. The earliest lunisolar months, then, were pumimanta, that is, the name of the full moon corresponded to the name of the month. Of course, the full moon occurs at all nakshatras. Fifteen were taken into account for the naming of the month, spaced more or less equally. We thus have the following set of names along with their respective nakshatras:

Rashi	Approximate nakshatra on Purnima	Lunar month name	Solar month name
Mesha	Chitra	Chaitra	Vaisakha
Vaishnava	Visakha	Vaisakha	Jyaistha
Mithuna	Jyestha	Jaishta	Aashaadha
Karkata	(Purva & Uttara) Aashaadha	Aashaadha	Saravana
Simha	Sravana	Saravana	Bhadrapada
Kanya	(Purva & Uttara) Bhadrapada	Bhadrapada	Asvayuja (Aasvina)
Tula	Asvini	Asvayuja	Kaarthika (Aasvina)
Vrischika	Krittika	Kaarthika	Maarghasira
Dhanush	Mrugasira	Maarghasira	Pausa (Pushyam)
Makara	Pushyami	Pausa	Maagha (Pushyam)
Kumbha	Maagha	Maagha	Phalguna
Mina	(Uttara & Purva) Phalguni	Phalguna	Chaitra

Question 34.
Explain our Solar System in detail?
Answer
The Sun along with the eight planets, their moons, asteroids, comets and meteors constitute our solar system.

Sun is the biggest star of our solar system. The diameter of the Sun is 109 times the diameter of the earth. Sun is approximately 300000 times heavier than the earth. Sun is a huge bright ball comprising hydrogen and helium gases. It is the primary source of energy. Formation of day and night, change of seasons and formation of rain all these occur because of Sun. The life of all living beings depends upon solar energy.

A solid heavenly body which revolves around the Sun in a closed circular orbit is called a planet. There are eight planets in all, including the earth. All planets rotate from the west to the east except Venus, which rotates from east to west. Due to their different speeds, the position of the planets with respect to the earth changes every day. In Indian, the planets are called Graha. The small pieces of rocks or metals which revolve around the Sun between Mars and Jupiter are called asteroids.

The bright star-like objects with a long tail, approaching the Sun, in a highly elliptical orbit are called comets.

The bright star-like objects which appear suddenly in the sky, for a few moments and glow with a brilliant white flash of light falling towards the earth and finally disappearing, are called meteors. It is believed, that meteors are the debris of comets floating in the sky. When a chunk of this debris enters the gravitational field of the earth, it starts falling towards the earth. When it passes through the atmosphere, it becomes white hot, on account of friction of the atmosphere. Thus, it catches fire and appears like a brilliant flash of light. Meteors are commonly known as shooting stars, though they are not stars.

If a meteor is too big and fails to burn completely in the atmosphere, then a part of it reaches the surface of the Earth. The unburnt piece of a meteor, which reaches the surface of the earth, is called a meteorite.

In the Solar System, there are three types of Planets:

They are:

• Terrestrial Planets- Mercury, Venus, Earth, Mars.
• Heavier Planets- Jupiter, Saturn, Neptune, and Uranus.
• Dwarf Planets- Yama.Pluto etc.

1. Mercury [Budha]: It is the first planet in the solar system and is closest to the Sun. Because’ of its closeness to the sun, it is one of the hottest planets in the solar system. The surface features of mercury are similar to that of the moon. It neither has water nor atmosphere. Because of his extremely high temperature, lack of water and atmosphere, life is not possible.

2. Venus [Shukraj]: It is the second planet from the sun. Except for the sun, and the moon, it outshines all the heavenly bodies and hence, regarded as the brightest and hottest planet. It appears as an evening star, just above the western horizon for 292 days. After this, it appears as a morning star for another 292 days in the eastern horizon. In spite of the fact that Venice is the second in distance from the sun, as compared to Mercury, it is the brightest due to the cloudy atmosphere of carbon dioxide. This cover reflects more than of the sunlight falling on its surface. The mass of Venus is 0.8 times the mass of the earth. However, its’size is almost similar to that of the Earth.

3. Earth [Prithvi]: Earth is the third planet from the Sun. The tilted axis of rotation of the earth is always in the same direction. Due to this tilt in the axis of rotation, the position of the northern and southern hemispheres of the Earth towards the sun keeps on changing, throughout the year.

4. Mars [Mangal]: It appears like a red star and hence, it is sometimes called the Red Planet. There are two moons revolving around it. namely, Phobos and Deimos. Both these moons are very close to the surface of the Mars and are less than 20 km in diameter.

5. Jupiter [Guru or Brihaspati]: It is the largest planet in the solar system. One special feature of this planet is a great red spot, which is 30000 km long and 13000 km wide. It is known to have 61 moons. It has a faint ring around its equatorial plane.

6. Saturn [Shani]: Saturn is surrounded by three flat rings, which consist of rocks whose size may vary from a speck to a few kilometres in diameter. Among them, the second ring B is the brightest. It has 31 known moons, the largest being Titan. Besides, in Vedic astrology, Rahu and Ketu are known as invisible planets or shadowy planets.

Celestial Bodies and Indian Calendar Addition Questions Solved

Multiple Choice Questions (MCQs)Question 1.
The substance which constitutes the material of the Sun and stars is:
(A) helium
(B) hydrogen
(C) carbon
(D) uranium
Answer: B

Question 2.
A heavenly body with a long tail is called a/an:
(A) asteroid
(B) meteor
(C) comet
(D) pluton
Answer: C

Question 3.
When the moon is not visible at night in a clear sky, the moon is called:
(A) full moon
(B) eclipsed moon
(C) dark moon
(D) new moon
Answer: D

Question 4.
Which of the following is not a planet of our Sun?
(A) Pluto
(B) Neptune
(C) Earth
(D) Jupiter
Answer: A

Question 5.
Which one of the following is not a member of our solar system?
(A) comet
(B) constellation
(C) asteriod
(D) meteor
Answer: A

Question 6.
A group of stars which appear in clusters, are called a:
(A) asteroids
(B) Milky way
(C) constellation
(D) None of these
Answer: C

Question 7.
The vast unimaginable space which encompasses most distant stars, planets and anything else, which exists, is called:
(A) Sky
(B) Universe
(C) Both (A) and (B)
(D) None of these
Answer: A

Question 8.
Bodies like earth, moon, planets, sun, stars,meteors, comets, etc. are known as:
(A) Heavenly bodies
(B) Celestial bodies
(C) Both (A) and (B)
(D) None of these
Answer: C

Question 9.
Planets are heavenly bodies which:
(A) Revolve round the sun in the same way as our earth
(B) are eight in numbers
(C) do not twinkle
(D) All of these
Answer: D

Question 10.
Sun is the:
(A) Nearest star from the earth
(B) Medium-order star in terms of its mass brightness
(C) Both (A) and (B)
(D) None of these
Answer: C

Question 11.
Nakshatra is divided into how many parts?
(A) 2
(B) 4
(C) 6
(D) 9
Answer: B

Question 12.
A planet which is commonly called Evening Star:
(A) Mercury
(B) Venus
(C) Pluto
(D) Mars
Answer: B

Question 13.
The number of planets according to Indian Panchang are:
(A) 7
(B) 10
(C) 8
(D) 9
Answer: D

Question 14.
Pratipada tithi will be the interval of:
(A) 12 – 24
(B) 10 – 24
(C) 20 – 24
(D) None of these
Answer: A

Question 15.
Siddhanta Siromani is written by:
(A) Aryabhatta
(B) Bhaskara
(C) Bhaskara II
(D) Varamihira
Answer: C

Celestial Bodies and Indian Calendar Very Short Answer Type Questions

Question 1.
Name the bodies of the solar system that have failed to assemble into a planet?
Answer
Asteroids.

Question 2.
Name the planet that is known to have the largest number of natural satellites.
Answer
Saturn, having 30 satellites.

Question 3.
Which planet of the solar system is largest and smallest in size?
Answer
(a) Largest planet- Jupiter
(b) Smallest planet- Mercury.

Question 4.
Who gave the relation between circumference and diameter of circle?
Answer
Aryabhatta.

Question 5.
Rashi contains how many charans?
Answer
Nine.

Question 6.
Planets revolue in which direction?
Answer
West to East.

Question 7.
Name the two satellites of Mars?
Answer
Phobos and Deimos.

Question 8.
How does the phases of moon occurs?
Answer
The phases of moon occurs due to relative change in the position of the earth and moon, while revolving around the Sun.

Question 9.
What are Asteroids?
Answer
Asteroids are the small piece of rocks or metals which revolve around the Sun, between the orbits of Mars and Jupiter.

Question 10.
What are comets?
Answer
The bright shiny star-like objects with a long tail, approaching the sun in a highly elliptical orbit are comets.

Celestial Bodies and Indian Calendar Short Answer Type Questions

Question 1.
What are cetestial bodies? Name some of these?
Answer
The heavenly bodies found outside the earth’s atmosphere, either small or massive in size are called celestial bodies. For example, stars, Sun, Moon, planets etc.

Question 2.
Write two features of a constellation?
Answer
Constellation has the following characteristics:

1. It is a group of a few stars.
2. A constellation appears to resemble an animal or a human being or some other known object in shape.

Question 3.
What are the Planets? How are they different from a Star?
Answer
A solid heavenly body which revolves around the Sun in a closed circular orbit is called a planet.
Star:

1. Stars have their own light.
2. Stars produce their own energy, due to the fusion of hydrogen.
3. Stars appear to twinkle at night.
4. Stars have enormous mass.
5. Stars do not change their relative position in the sky, every day.
6. Stars appear to move from east to west in the sky.

Planet:

1. Planets do not have their own light.
2. Planets do not produce their own energy. They have to depend upon the Sun for energy.
3. Planets do not twinkle at night.
4. Planets have insignificant mass, compared to the stars.
5. Planets change their position in the sky, on a daily basis.
6. Planets appear to rotate from the west to east in the sky.

Question 4.
Classify the following into planets, satellites, stars and constellation. Moon, Alpha centuri, Neptune, Orion, Mercury, Ursa major, Sun, Phobos.
Answer
Planets: Neptune, Mercury.
Stars: Alpha Centuri, Sun. Constellations: Orion, Ursa Major. Satellite: Moon, Phobos.

Question 5.
Name a celestial body which is not a star, but is called a star. Explain.
Answer
Venus is a planet. It is called as the morning star or evening star, due to its appearance as a very bright dot, just before Sunrise for about eight weeks in the eastern sky and for about eight weeks in the western region of the sky immediately, after sunset.

Question 6.
Why Uttarayan is considered as an auspicious period?
Answer
In Hindu religion, people believed that if a person dies in uttarayan that person is supposed to go to heaven.

Question 7.
What are Basant and Sharad equinox?
Answer
An equinox is an astronomical event in which the plane of Earth’s equator passes through the centre of the Sun. It occurs twice each year around 20 March and 23 September.On an equinox, days and nights are of approx equal duration, all over the planet, due to the angular size of the Sun and atmospheric refraction.

Celestial Bodies and Indian Calendar Long Answer Type Questions

Question 1.
Write the biography of Varamihira and explain the scientific works of Varamihira in detail?
Answer
Varahmihira was born in 499 A.D., in a family of Brahmins, settled at Kapittha, a village near Ujjain. His father, Adityadasa was a worshipper of the god Sun and it was he, who taught Varahamihira, astrology. On a visit to Kusumapura (Patna), young Varahamihira met the great astronomer and mathematician, Aryabhatta. The meeting inspired him so much, that he decided to take up astrology and astronomy as a lifetime pursuit. At that time, Ujjain was the centre of learning, where many schools of arts, science and culture were flourishing, in the prosperity of the Gupta reign. Varahamihira therefore, shifted to this city, where scholars from distant lands were gathering.

In due course, his astrological skills came to the notice of Vikramaditya Chandragupta II, who made him, one of the Nine Gems of his court. Varahamihira’s mathematical work included the discovery of the trigonometric formulas. He improved the accuracy of the sine tables of Aryabhata-I. He defined the algebraic properties of zero as well as that of negative numbers. Furthermore, he was among the first mathematicians, to discover a version of what is now known as Pascal’s triangle. He used it to calculate the binomial coefficients.

His treatise such as Pancha Siddhantika (Five Principles), Brihatsamhita (Master collection), Brahjataka (Astrological work) have put him on as high a pedestal in Astrology, as Kautilya’s in Political philosophy, Manu’s in Law or Panini’s in Grammar.

Varahamihira’s main work is the book Pancha Siddhantika (“Treatise on the five Astronomical Canon’s which gives information about old Indian texts, which are now lost). The work seems to be a treastise on mathematical astronomy and it summarises five earlier astronomical treatises, namely, the Surya Siddhanta

Romaka Siddhanta, Paulisa Siddhanta, Vasishtha Siddhanta and Paitama Siddhanta. Panch Siddhanta holds a prominent place, in the realms of astronomy.

Varahamihira was learned in the Vedas, but he was not a blind believer in the supernatural. He was a scientist. Like Aryabhatta before him, he declared that the earth was spherical. In the history of science, he was the first to claim that some “Force” might be keeping bodies stuck to the round earth. The force is now called gravity.

Question 2.
Explain the phases of the Moon.
Answer
Moon is a non-luminous body. It has no light of its own. It only reflects the light of the sun falling on its surface. When this reflected light reaches the earth, we see the moon. Only that part of the moon is visible, which reflects the sunlight towards the earth. On the New Moon Day, the moon is present between the sun and the earth. Thus, the reflected light from ‘the moon does not reach the earth, and hence, is not visible.

The night just after the new moon day, we see the crescent moon. It happens because only the reflected light from the crescent part reaches the earth. The rest of the moon is only faintly visible because the sunlight reflected from the earth also falls on the moon’s disc.

The crescent goes on increasing every day, till, on the fifteenth day, the full bright face of the moon is visible. On this day the earth is between the sun and the moon, such that the night side of the earth is facing the day side of the moon. This is called full moon day. This gradual increase in the bright disc of the moon is called waxing of the moon.

After the full moon, the bright face of the moon goes on decreasing every night. This decrease in the bright disc of the moon is called waning of the moon. By another fifteen days, the new moon is formed. This waxing and waning of the disc of the moon, are the moon revolves around the earth is called phases of the moon.

Question 3.
What is Panchang? Write its parts.
Answer
Panchang consists of two words: Panch- Five Ang-Parts. Panchang is a Hindi word and made up of 5 parts:
1. Tithi: It is calculated with the help of position of Sun and Moon, in transit. Tithi is calculated by Moon longitude of Sun longitude. Tithi vridhi is the tithi present at sunrise on the first day, as well as on the second day, and so on. Days- Seven days of the week are: Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday.

2. Nakshatras: The 360-degree zodiac is divided into 27 parts to achieve nakshatras. There were 27 nakshatras. Every Nakshatra is divided into 4 A Rashi consist of two and a quarter of a Nakshatra.

3.Yoga: There are 27 yogas, it is calculated by (moon longitude + sun longitude)/13 degree, 20 minutes.

4. Karan: One tithi consists of two Karan. There are total 11 Karan. Among them, 4 are fixed and seven are not fixed. Karan is calculated by tithi.

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