Some Important Definitions:
Cosmology:
Cosmology is the science of the cosmos or universe.
OR
Cosmology is the branch of physical science which deals with the Universe.
Universe:
The universe is the sum total of all that exists, or has existed, both in space and time.
Galaxy:
A galaxy is a system of many thousands of millions of stars together with inter-stellar gas and dust.
OR
Galaxy is a fundamental unit of the universe. It is composed of hundreds of thousands of stars together with intra-stellar gas and dust.
Star:
Those heavenly bodies which are luminous and produce their own energy by nuclear reactions are called stars.
• Proximal Centauri second nearest after Sun to the Earth.
• Antares is one of the largest stars known.
Solar system:
A tiny system of our galaxy which consists of the /sun, a planet and their satellites, thousands of miniature planets called asteroids, meteoroids, comets, interplanetary dust and plasma.
Satellite:
Those heavenly bodies which revolve round the planets are called satellites.
Eclipse:
In astronomy, the term eclipse simply means the obscuring of one heavenly body by another, particularly that of the sun or a planetary satellite.
Lunar Eclipse:
A condition when the earth comes in between the sun and the moon and throws its shadow on the moon is called lunar eclipse.
Solar Eclipse:
A condition when the moon comes in between the sun and the moon and throws its shadow on the moon is called Solar Eclipse.
Astrology:
Astrology is the interpretation of the influence of planets and stars on human lives.
Asteroids:
Small, irregular shaped rocky objects which orbit the sun between the orbits of Mars and Jupiter are called Asteroids.
Meteorites:
Tiny chunk of material floating in space which can also enter the earth’s atmosphere and become meteor are known as meteorites.
Comets:
The bodies mainly composed of ice and dust which revolve round the sun are called comets.