1- Universe -The Universe is everything that exists on celestial bodies and the space between them.
2- Galaxy – A group of stars is called a galaxy.
3-Asteroids – A large number of small bodies revolve around the sun between Mars and Jupiter are called Asteroids.
4-The mass of the Jupiter is 318 times that of the earth.
5-Saturn is yellowish colour planet.
6- Mars is the reddish planet.
7-The stars are not visible during day time because of the glare of bright sunlight.
8-Mars has two planets.
9-Uranus rotates on its axis from east to west just like Venus.
10-Halley Comet was seen in 1986. It can reappears 76 years later i.e in 2062.
11-The shape of the moon is spherical. The shape changes due to the rotation of the earth on its own axis as well as due to the rotation of the moon around the earth.
12-Great bear constellation, Casseopia constellation,Orion and Leo are some constellations.
13-The objects which are found on the sky are called celestial objects.
14-On the new moon day, sun and moon are on the same side of the earth.
15-On the full moon day, the sun and moon are on either sides of the earth.
16-The Pole star is situated in the direction of the earth’s axis and hence it appears as not moving.
17-A Meteor is a small object that occasionally enters the earth’s atmosphere.
18-A body that reaches the earth is called a Meteorite.
19-Artificial satellites are revolving at a height of 38,000 km from the surface of the earth and 44,300 km from the centre of the earth.
20-The time period of the artificial satellite in stationary orbit is 24 hours.