Space: Space means the whole universe including the earth.
Outer Space: Outer Space means all space other than the earth. Outer space is vast.
Milky Way: Milky Way is our home galaxy. The Milky Way is faint band of light crossing the night sky. It consists of stars in the Plane of our Galaxy. Milky Way is a spiral Galaxy about 100,000 light years in diameter, containing at least 100 billion stars, like our sun.
Galaxy: The cluster or bunch of billions stars. There are about 100 billion galaxies in the universe.
Nebula: Nebula is the cloud of gas and dust in the space. Nebula is the birth-place of stars.
Solar System: Solar System comprises of the sun and the nine other planets which orbit the sun.
The Sun: The Sun is the star at the center of the solar system. The Sun is about 4.7 billion years old and is composed about 70% hydrogen and 30% helium with other elements making up less than 1%. The Sun is at the distance of about 32,000 light years from the center of the Galaxy. The diameter of the Sun is 1,392,000km.
Planets: The Planets are large celestial bodies in orbit around a star (SUN), composed of rock, metal or gas. There are nine planets in our solar system. They are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Neptune, Uranus and Pluto.
Meteors: Meteor, the flash of light in the sky, popularly known as falling star or shooting star is caused by a particles of dust. Meteoroid is a piece of rock or metal like substance from space that reaches the earth’s surface or the surface of other celestial body.
Satellites: Satellites are small bodies that orbit a large one, either natural or artificial..
The Moon: The Moon is the natural satellite of our earth and is its nearest neighbor in space.
Comets: Comets are small icy bodies orbiting the sun, usually on a highly elliptical path.
Light Year: One light year is the distance light travels in one year at nearly 3, 00, 00 km a second. This is the speed of the light.
Eclipses: Eclipse is the passage of an astronomical body through the shadow of another.
Lunar Eclipse: The moon is said to be in eclipse when the earth comes between the moon and the sun and this is called lunar eclipse.
Solar Eclipse: The sun is said to be in eclipse when the moon comes between the sun and the earth and this is called as Solar Eclipse.
Tides: The tide is rise and fall of sea level due to the gravitational forces of the moon and the sun. The rise in the water level is called as high tide and the fall is called as low or ebb tide.
Atmosphere: Atmosphere is the mixture of gasses that surrounds the Earth, prevented from escaping by the pull of the Earth’s gravity.