CLASS- XI
CHAPTER-02:- THE ORIGIN AND
EVOLUTION OF THE EARTH
What do you know about 'Nebular Hypothesis'?
Nebular Hypothesis considered that the planets were formed out of a
cloud of material associated with a youthful sun, which was slowly
rotating.
What is a nebula?
A galaxy starts to form by accumulation of hydrogen gas in the form of a
very large cloud. This slow circular moving gaseous clouds are called
nebula.
Define the term Planetesimals?
The gas cloud starts getting condensed and the matter around the core
develops into small-rounded objects. These small-rounded objects by the
process of cohesion develop into what is called planetesimals.
Define the term Galaxy.
Galaxy is defined as a cluster of millions of stars and solar systems.
What does the light year measure?
A light year is a measure of distance and not of time.
Which evidence was given by Edwin Hubble?
Edwin Hubble provided the evidence that the universe is expanding. With
time, the galaxies move further and further away.
Name a theory which is associated with the origin of the earth?
Nebular Hypothesis is associated with the origin of earth.
Which theory is most widely accepted regarding origin of the
universe at present?
The Big Bang Theory is mostly accepted regarding the origin of universe.
, What are Jovian Planets?
Jupiter, Saturn, Uranus and Neptune are called Jovian or Gas Giant planets.
Jovian means Jupiter-like. Most of them are much larger than the
terrestrial planets and have thick atmosphere, mostly of helium and
hydrogen.
Define solar system?
It consists of the sun, 8 planets, 63 moons, millions of smaller bodies like
asteroids and comets and huge quantity of dust grains and gases.
What are terrestrial planets?
Terrestrial planets are those planets which are formed in the close vicinity
of the parent star where it was too warm for gases to condense to solid
particles. Mercury , Venus, Earth and Mars are known terrestrial planets.
What is the diameter of the Milky Way ?
The diameter is between 80,000 to 1,50,000 light years.
Why do we study the celestial bodies?
We study the celestial bodies to know about the origin, evolution and
function of each and every celestial bodies.
What do you mean by light year?
A light year is equal to the number of kilometers travelled by light per
second. It is a measure of distance and not of time. Light travels at a speed
of 300,000 km/second. Considering this, the distances the light will travel
in one year is taken to be one light year. This equals to 9.461x1012 km. The
mean distance between the sun and the earth is 149,598,000 km. In terms
of light years, it is 8.311 minutes of a year. Light travels at a speed of
300,000 km/second. Therefore, the distances that the light will travel in
one year is taken to be one light year.
Name the various hypothesis associated with the formation of the
earth.
The various hypothesis associated with the formation of the earth are:
CHAPTER-02:- THE ORIGIN AND
EVOLUTION OF THE EARTH
What do you know about 'Nebular Hypothesis'?
Nebular Hypothesis considered that the planets were formed out of a
cloud of material associated with a youthful sun, which was slowly
rotating.
What is a nebula?
A galaxy starts to form by accumulation of hydrogen gas in the form of a
very large cloud. This slow circular moving gaseous clouds are called
nebula.
Define the term Planetesimals?
The gas cloud starts getting condensed and the matter around the core
develops into small-rounded objects. These small-rounded objects by the
process of cohesion develop into what is called planetesimals.
Define the term Galaxy.
Galaxy is defined as a cluster of millions of stars and solar systems.
What does the light year measure?
A light year is a measure of distance and not of time.
Which evidence was given by Edwin Hubble?
Edwin Hubble provided the evidence that the universe is expanding. With
time, the galaxies move further and further away.
Name a theory which is associated with the origin of the earth?
Nebular Hypothesis is associated with the origin of earth.
Which theory is most widely accepted regarding origin of the
universe at present?
The Big Bang Theory is mostly accepted regarding the origin of universe.
, What are Jovian Planets?
Jupiter, Saturn, Uranus and Neptune are called Jovian or Gas Giant planets.
Jovian means Jupiter-like. Most of them are much larger than the
terrestrial planets and have thick atmosphere, mostly of helium and
hydrogen.
Define solar system?
It consists of the sun, 8 planets, 63 moons, millions of smaller bodies like
asteroids and comets and huge quantity of dust grains and gases.
What are terrestrial planets?
Terrestrial planets are those planets which are formed in the close vicinity
of the parent star where it was too warm for gases to condense to solid
particles. Mercury , Venus, Earth and Mars are known terrestrial planets.
What is the diameter of the Milky Way ?
The diameter is between 80,000 to 1,50,000 light years.
Why do we study the celestial bodies?
We study the celestial bodies to know about the origin, evolution and
function of each and every celestial bodies.
What do you mean by light year?
A light year is equal to the number of kilometers travelled by light per
second. It is a measure of distance and not of time. Light travels at a speed
of 300,000 km/second. Considering this, the distances the light will travel
in one year is taken to be one light year. This equals to 9.461x1012 km. The
mean distance between the sun and the earth is 149,598,000 km. In terms
of light years, it is 8.311 minutes of a year. Light travels at a speed of
300,000 km/second. Therefore, the distances that the light will travel in
one year is taken to be one light year.
Name the various hypothesis associated with the formation of the
earth.
The various hypothesis associated with the formation of the earth are:
