Download Halley`s comet

Our Solar System
• Formed about five billion years ago from a
giant cloud of gas and debris
• Gravity caused Earth and other planets to
become layered according to density
differences in their material.
Planets differ from stars:
• Planets are colder and shine by reflective light
• Stars generate their own light through nuclear
fusion reactions
The characteristics of the planets are affected by
each planets location in relationship to the sun
• The Terrestrial planets are small, rocky, and
dense
– Mercury, Venus, Earth, and Mars
– Resemble Earth in size and rocky compostion
Venus is the hottest planet
Why does Mercury and the Moon have more
impact craters on their surface than Earth?
• The Earth has an atmosphere that protects us.
• The Earth has weathering and erosion that
breaks down the craters on the Earth’s
surface.
The Jovian planets are large, gaseous, and low
density
• Jupiter, Saturn, Uranus, and Neptune
• Gas Planets
Pluto
• Farthest from the Sun
• A special case among the Planets
Asteroids, Comets, meteors are components of
our solar system
• Impact events have been correlated with the
mass extinction and global climate change
• Impact craters can be identified on the Earth’s
crust
Asteroids
• Located mostly in a belt between the orbits of
Mars and Jupiter
• Tens of Thousands in number
Meteors
• Small solid particles from space that can be
caught by Earth’s gravity and dragged down
through the atmosphere
• As they are heated by friction with Earth’s
atmosphere, they burn up producing streaks
of light.
Comets
• Icy Objects
• Most originate in a region outside the planets
• Have an elliptical orbit around the sun
• Halley's Comet
• Halley's comet will next appear in the night
sky in the year 2062. It orbits the sun every
75-76 years