STRUCTURES
QASIM UMER
Civil Services Preparatory School Contact: 033391688521
, Basic Concepts of Universe
• Comets
• Objects made up of ice, metals and dust moves around the sun.
• 3 parts solid center, head around center of dust and ice, long tail.
• Asteroids (Star Like)
• Comets without ice
• Small rocky objects that revolve around sun, CERES
• Most asteroids are formed between Mars and Jupiter.
• Meteoroids
• Small iron and rocky objects resulting from collision of asteroids.
• These are also formed when comets are disintegrated
• When they entre earths atmosphere burning due to friction meteor
Civil Services Preparatory School Contact: 033391688521
, Basic Concepts of Universe
• Nebula
• Greek word means cloud
• In sky, there are cloud like objects composed of gas and dust which are classified
Nebula.
• Constellation
• These are groups of star in sky.
• UFO
• The Universe
• Total of all that exists or has existed before. Universe is composed of billion of
galaxies. 1011 to 1012
• Star
• Astronomical object composed of hot gases that emits electromagnetic radiations,
especially light.
Civil Services Preparatory School Contact: 033391688521
, Basic Concepts of Universe
• Black Hole
• Theoretical object of extreme density and gravitational field that nothing can escape from
therefore, it appears totally black.
• Light year
• Distance travelled by light in one year.
• Astronomy
• It is a branch of science which investigates all the matter and energy in the universe.
• Cosmology
• Astronomy also includes cosmology, which is the study of the structure, origin and evolut
of the universe.
• Astrology
• It is the study of the movements and relative position of the celestial bodies.
• Asteroid<Moon<Sun<Star<Solar System<Galaxy<Universe
Civil Services Preparatory School Contact: 033391688521