UNIT 1: Origin And Understanding Of Universe Flashcards

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1
Q

One of the earliest and famous hypothesis was given by German philosopher

A

Immanuel Kant

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2
Q

In 1796 what theory was given by a Mathematician_____________ and what did the theory state

A

Nebular Hypothesis

Laplace

Sun was rotating, slowly and the formation of planets was associated with a cloud of material related to a youthful sun.

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3
Q

A wandering star approached the sun. A material was extended in cigar shape and got separated from the solar surface. With the moving of the passing star, that separated material from the solar surface continued to revolve around the sun and then got condensed slowly forming the planets;

Who, When, who all supported it, what were the arguments called and why

A

Chamberlain, Moulton
1900

Sir James Jeans, Sir Harold Jeffery

“Binary theories”-the arguments considered a companion to the sun to have been coexisting, an these arguments are called binary theories

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4
Q

Later, who are revised the nebular hypothesis when and what was it

A

Otto Schmidt in Russia and Carl Weizacar in Germany, 1950

They argued that the sun was surrounded by a solar nebula containing mostly hydrogen, helium and dust. It also argued that a disk-shaped cloud was formed due tot he friction and collision of particles, and the planets were formed through the process of accretion. However, later scientists took up the problems of the origin of the entire universe and not just that of the earth or the planets.

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5
Q

Who and when provided the evidence suggesting that the universe is expanding or we can say that the distance between the galaxies were found to be increasing, as the time crosses, galaxies will further move apart.

A

1920 Edwin Hubble

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6
Q

What are the three stages of Big Bang theory

A
  1. “Tiny ball “ (singular atom) at one place, which had infinite temperature and density, and an unimaginably small volume
  2. It exploded. First atom began to form within the first three minutes
  3. The temperature dropped to 4500K within 300,000 years and the atomic matter emerged
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7
Q

When did Big Bang take place

A

13.7 Billion years ago

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8
Q

What is an alternative Bigbang theory

A

Hoyle’s concept of steady state

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9
Q

Why was Hoyle’s concept of steady state regected

A

Cause it proposed that the universe would be of the same size at any given point of time

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10
Q

Evidence that proves that the Universe is expanding

A
  1. Redshift of the objects in the universe
  2. Hubble law
  3. The presence of Cosmic Microwave background
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11
Q

Redshift of the objects in the universe

A

Movement of objects relative to us is measured using the Doppler shift. Done by measuring the frequency of the objects. Light also has a Doppler shift.

Light coming towards us: blue shift
Light going away from us: red shift

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12
Q

Hubble law

A

This law suggests that the velocity of recession is proportional to the distance of the galaxy from us. Astronomer, Edwin Hubble measured in 1929, the velocities of a large selections of galaxies and found that the majority of galaxies are moving away from us.

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13
Q

Cosmic Microwave background

A

According to the Bigbang, theory, the early universe was a very hot place and the gas within it get cool, as it expands. This means there should be radiation, meaning the leftover heat from the Big Bang, called the “cosmic microwave background”, or CMB all over the universe. Thus, the existence of the CMB radiation was observed in 1965 by Arno Penzias and Robert Wilson. Presently, the the temperature of the CMB radiation is at 2.725degrees above absolute zero

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14
Q

The existence of CMB was observed in ____ by______. Presently the CMB radiation is at _______

A

1965
Arno Penzias, Robert Wilson
2.725˚ above absolute zero

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15
Q

_____________ gave rise to gravitational forces

A

Density differences

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16
Q

Hydrogen gas started accumulating as a huge cloud called

A

Nebula

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17
Q

Nebula——> ______————> __________———->

A

Localised clumps of gas
Dense gaseous bodies
Stars

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18
Q

When was stars formed

A

5-6 billion years ago

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19
Q

Individual galaxies have diameters ranging from

A

80,000-150,000 light years

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20
Q

What are the types of Galaxies

A

3 types

  1. Elliptical galaxies: spheroid or an elongated sphere shape; two dimensional
  2. Spiral galaxies: Bulge, disk or halo; Milky Way
  3. Irregular galaxy: No regular shape; asymmetrical
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21
Q

The condensation of gas cloud develops as small circular objects around the core. With the help of the process of cohesion, these small circular objects develop into ________ which comprises a large number of small bodies

A

Planetesimals

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22
Q

When was the solar system formed

A

9 billion years ago; 4.5 billion years ago; conflicting sources

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23
Q

Stages in which solar system was formed

A
  1. Supernova
  2. Solar Nebula
  3. Formation of the sun
  4. Formation of other planets
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24
Q

Solar system comprises of

A
  1. Planets
  2. Dwarf planets
  3. Moons
  4. Asteroids
  5. Comets
  6. Meteoroids
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25
Q

Terrestrial plants Jovian planets

A

First four

Last four

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26
Q

When was Pluto deemed as a Dwarf planet and by whom?

A

International Astronomical Union
August 24, 2006

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27
Q

Difference between the terrestrial and Jovian planets

A
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28
Q

When was sun formed and how far is it

A

5-6 billion years ago
150 million km

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29
Q

How long can sun go further

A

5 billion years

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30
Q

Layers of the sun

A
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31
Q

Mercury is not the hottest because

A

It does not have the atmosphere

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32
Q

Mercury does not have any moons and it takes____ days to complete one rotation and ___ days for one revolution

A

59
88

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33
Q

Which is the densest planet in the solar system

A

Earth

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34
Q

Which is the second densest planet in the solar system

A

Mercury

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35
Q

Size of mercury is _____ of earth

A

1/3

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36
Q

Mercury has the smallest ______ and ________ of its orbit is the largest of all planets

A

Tilt
Eccentricity

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37
Q

Mercury has ______ instead of atmosphere and it mainly contains of

A

Thin exosphere

Oxygen, sodium, hydrogen, helium and potassium

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38
Q

______ is the sixth largest planet

A

Venus

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39
Q

_______ is the hottest and brightest planet of the solar system and why

A

Venus

Because its full of carbon di oxide and clouds made up of sulfuric acid

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40
Q

_____ is considered to be an active planet and why

A

Venus
it has volcanoes

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41
Q

_______is called earth’s twin and why

A

Venus
Similar in size and density

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42
Q

Which rotates from east-west

A

Venus, mercury

Uranus too but it rotates on its side

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43
Q

Which planets does not have moon

A

Mercury and Venus

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44
Q

Venus completes one revolution in

A

225 days

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45
Q

Venus completes one rotation in

A

243 days

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46
Q

Which is the fifth largest planet in the solar system

A

Earth

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47
Q

Water covers _____ percentage of earth’s surface

A

71

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48
Q

Earth’s atmosphere is composed of

A

77-nitrogen
21-oxygen
Traces of argon, carbon di oxide and water

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49
Q

Earth revolution

A

356+1/4 days

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50
Q

Why does earth have seasons

A

23.5˚angle tilt

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51
Q

Which is the second smallest planet

A

Mars

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52
Q

_______ is like a cold desert, and half the size of earth

A

Mars

53
Q

Why is mars called red planet

A

Rusty iron

54
Q

Mars where does water exist

A

Thin clouds and icy dirt

55
Q

Whats Mars atmosphere made of?

A

Carbon di oxide, nitrogen, and argon

56
Q

______ mass is less than 10 times of the earth

A

Mars

57
Q

The Axis of rotation of Mars is tilted at

A

25.2˚

58
Q

What are the two moons of mars

A

Phobos and Deimos

59
Q

Which is the biggest of the eight planets?

A

Jupiter

60
Q

What is the biggest storm found on mars

A

Great Red Spot

61
Q

Is Jupiter solid or gas

A

Its a giant planet, but without a solid surface and it may have a solid inner core

62
Q

What is the mass of Jupiter relative to other planets?

A

The mass of the Jupiter is more than twice as that of all the other planets combined.

It has 318 times the mass than that of the Earth

63
Q

Jupiter is the _______ brightest object after ________, _______, ________.

A

Fourth brightest object

Sun
The Moon
Venus

64
Q

Atmosphere of Jupiter consists of

A

90% Hydrogen
10% Helium

Methane, water ammonia and rock

65
Q

Jupiter has conformed _______ moon, and the largest one is called ________, which is also the biggest one in the solar system. The three other moons are _____, _________, and __________. All these four are called____________.

A

67 moons,
Ganymede
Io, Europa, Callisto
Galilean Moons

66
Q

Why does Jupiter does not have seasons

A

Because its tilted only at an angel of 3.13˚

67
Q

What are the bright ringlets of Saturn made of ?

A

Ice and rock

68
Q

What is Saturn called

A

The Ringed Planet

69
Q

______________ is the farthest planet that can still be viewed with the naked eye.

A

Saturn

70
Q

How many moons does Saturn have?

A

150 moons

71
Q

What is the largest moon of Saturn?

A

Titan

72
Q

What is the second largest moon in the solar system?

A

Titan

73
Q

What is the atmosphere of titan made of

A

Nitrogen

74
Q

What angle is Saturn tilted at

A

27˚

75
Q

Which planet of the solar system, have the lowest density

A

Saturn

76
Q

What is the appearance of Saturn and why is it so

A

Yellow
Atmospheric layer composed of ammonia crystals. Below these crystals, there is a layer of clouds probably made up of water ice, and below that are the layers of sulfur ice and cold hydrogen mixtures.

77
Q

_________ what are the regular storms experienced by Saturn

A

Great White Spot

78
Q

Which is the third largest planet of the solar system?

A

Uranus

79
Q

What is Uranus made up of

A

Small rocky center above which it has water, methane and ammonia fluids

80
Q

What is Uranus’s atmosphere made of

A

Methane, hydrogen and Helium

81
Q

Uranus: ________- in its atmosphere gives it a _______ colour.

A

Methane
Blue

82
Q

Which is the only planet know to rotate on its side

A

Uranus

83
Q

How many known moons does Uranus have

A

27 known moons

84
Q

_________ diameter is 4 times as that of the Earth

A

Uranus

85
Q

The Volume of Uranus is _____ times greater than that of the Earth

A

63

86
Q

_________ takes the shortest time of all planets to complete one rotation and how much is it

A

Uranus
17 hours

87
Q

______ has the coldest atmosphere

A

Uranus

88
Q

________ and ______ are called ice giants

A

Uranus and Neptune

89
Q

What is the fourth largest planet

A

Neptune

90
Q

What planet has the same colour as that of Uranus

A

Neptune

91
Q

Neptune has how many rings

A

6 rings

92
Q

_________ planet has the highest density of all gas giants

A

Neptune

93
Q

How many moons does Neptune have

A

14

94
Q

What is the largest moon Neptune has

A

Triton

95
Q

Where is asteroid belt located

A

between mars and Jupiter

96
Q

Which is the only dwarf planet in the asteroid belt

A

Ceres

97
Q

What are the four largest asteroids of the belt

A

Ceres, Vesta, Pallas, Hygeia

98
Q

Meteorite

A

Meteoroid when it enters the earths atmosphere but does not completely burn up and hit the ground is called Meteorite

Which completely Burns are called meteors

99
Q

What are comets made of

A

Frozen gases, rock and dust.

Called as snowballs

100
Q

________ stretches away from the sun

A

Comet tail

101
Q

Billions of comets are orbiting our Sun in the ______________ and _________________.

A

Kuiper Belt
Oort Cloud

102
Q

Oort Cloud

A

It is an extended spherical shell of icy objects in the outermost stretch of the solar system. They are considered to be the source of origin of most of the long-period comets

103
Q

Kuiper Belt

A

This is a region beyond the 8 planets in the Solar System, extending from the orbit of Neptune. It is like an asteroid belt, but at least 20 times as wide as 20 to 200 times as massive as that of an asteroid belt. Most of the Kuiper Belt objects are mode of frozen volatiles, such as methane , ammonia and water. The Kuiper Belt has three dwarf planets- Haumea, Pluto and Makemake.

104
Q

What are the three dwarf planets Kuiper Belt has

A

Haumea, Pluto, and Makemake

105
Q

How old is Earth

A

4.5 to 4.6 billion years ago

106
Q

Which is the fifth largest planet of the solar system

A

Earth

107
Q

Earth is the largest among terrestrial plants in terms of

A

Density, mass and diameter

108
Q

Earth is of what shape

A

Gelid

109
Q

Temperature inside the earth increased due to the

A

Gradual increase in density

110
Q

Why does earth have crust, core and mantel

A

Heavier density elements sinked to the center

Moons gravitational pull, pulled the lighter materials upwards

111
Q

Evolution of atmosphere

A
  1. Loss of primordial atmosphere because of the impact of solar winds
  2. Cooling of earth resulted in gases and water vapour
  3. Photosynthesis, volcanic eruptions, gases expelled from earth
112
Q

Life began to evolve around

A

3800 million years ago

113
Q

The process of photosynthesis began around

A

2500-3000 million years ago

114
Q

Geological time scale

A
115
Q

Moon is also known as

A

Luna

116
Q

How is moon believed to be formed

A

“Giant impact”, “Giant Splat”

A body called their, thrice to the size of Mars collided with earth shortly after it was formed. It separated a part of the earth into space, which continued to orbit around the earth and took the form of moon about 4.44 billion years ago.

117
Q

The diameter of moon is _____ to that of earth

A

Quarter

118
Q

Moon completes revolution in about

A

27 days

119
Q

Which is the fifth largest moon in the solar system?

A

Earth’s Moon

120
Q

Which is the second brightest object in the sky (when seen from earth)

A

Moon

121
Q

The time taken by the moon for successive new moons is ________days

A

29.5

122
Q

Tides are caused by

A

Earth and the Moon

123
Q

The terrain of moon is primarily made of two types:

A

A. The highlands that are heavily cratered
B. The Maria that is relatively smooth and younger. The Maria are huge impact craters on the moon’s surface, which comprise about 16% of the surface.

124
Q

The moon has _____(atmosphere)

A

No

125
Q

It is suggested that there might be some water ice in ______________

A

In deep craters near the South Pole of the Moon as well as the North Pole.

126
Q

The crust of the moon is about ____________think on average

A

68km

127
Q

Unlike earth, moon’s interior is no longer

A

Active

128
Q

The moon’s surface mostly covered with a mixture of fine dust and rocky debris produced by meteor impacts called

A

Regality