-The
sun, the moon and all those objects shining in the night sky are called celestial
bodies.
-Stars
are celestial bodies which have their own heat and light and emit it in large
amounts.
-The
sun is a star.
-Various
patterns formed by different groups of stars are called constellations.
-Ursa
Major or Big Bear is one such constellation.
-One
of the most easily recognisable constellation is the small bear or Saptarishi
(Sapta-seven, rishi-sages). It is a group of seven stars.
-The
North star indicates the north direction. It is also called the Pole Star. It
always remains in the same position in the sky. We can locate the position of
the Pole Star with the help of the Saptarishi.
-Some
celestial bodies do not have their own heat and light. They are lit by the
light of the stars. Such bodies are called planets.
-The
word ‘planet’ comes from the Greek word “Planetai” which means ‘wanderers’.
-The
moon is a satellite. It is a companion of our earth and moves round it.
-The
sun, eight planets, satellites and some other celestial bodies known as
asteroids and meteoroids form the solar system.
-Those
who study the celestial bodies and their movements are called astronomers.
-Aryabhatta
was a famous astronomer of ancient India.
-Sun
provides the pulling force that binds the solar system.
-The
sun is about 150 million km away from the earth.
-There
are eight planets in our solar system. In order of their distance from the sun,
they are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
-Mercury
is
nearest to the sun. It takes only about 88 days to complete one round along its
orbit.
-Venus
is
considered as ‘Earth’s-twin’ because its size and shape are very much
similar
to that of the earth.
-The
earth is the third nearest planet to the sun. In size, it is the fifth
largest planet. It is slightly flattened at the poles. That is why, its shape
is described as a Geoid. Geoid means an earth-like shape.
-From
the outer space, the earth appears blue because its two-thirds surface is
covered by water. It is, therefore, called a blue planet.
-Jupiter,
Saturn and Uranus have rings around them. These are belts of small debris.
-Light
travels at the speed of about 300,000 km per second. Yet, even with this speed,
the light of the sun takes about eight minutes to reach the earth.
-Neil
Armstrong was the first man to step on the surface of the moon on 21 July 1969.
-Our
earth has only one satellite, that is, the moon.
-Moon
is about 3,84,400 km away from our earth.
-The
moon moves around the earth in about 27 days. It takes exactly the same time to
complete one spin. As a result, only one side of the moon is visible to us on the
earth.
-The
moon does not have conditions favourable for life. It has neither water nor
air. It has mountains, plains and depressions on its surface. These cast shadows
on the moon’s surface.
-A
Satellite is a celestial body that moves around the planets in the same way as
the planets move around the sun.
-Asteroids
are tiny bodies which move around the sun and they are found between the orbits
of Mars and Jupiter.
-The
small pieces of rocks which move around the sun are called meteoroids.
-A
galaxy is a huge system of billions of stars, and clouds of dust and gases.
- There are millions of such galaxies that make
the Universe.
-Our
solar system is a part of milky galaxy.
(Source: VI class NCERT Geography chapter - 1)
(Source: VI class NCERT Geography chapter - 1)