Download The Solar System, Planets and Small Celestial Bodies

The Solar System,
Planets and Small
Celestial Bodies
Big Bang Theory
• Scientific theory of the origin of the universe
• 10-15 billion years ago all matter came
together to one point
• Due to density and high temperature a huge
explosion (big bang) occurred
• Since the beginning universe has been
expanding
• Galaxies moving away from each other
Evidence for the Big Bang
• Red Shift
– Light shifting towards the red (longer
wavelengths) end of the spectrum
– Wavelengths getting longer
– Galaxy moving away from center of the universe
– Scientists use this as evidence that the big bang
occured
Models of the Solar System
• Geocentric – model that places Earth in the
middle of the solar system
• Heliocentric – model that places Sun in the
center of the solar system
Terrestrial Planets
• Four small, dense, rocky planets that orbit
closest to the Sun
– Mercury
– Venus
– Earth
– Mars
Gas Giants
• Have deep, massive gas
atmospheres, which are made up
of mostly hydrogen and helium
• Become denser as you travel
inside
• Small rocky cores
• Jupiter, Saturn, Uranus and
Neptune
Dwarf Planets
• Celestial bodies that orbit the sun
and range in size from 1500km to
2400km
Comet
• A small body of ice, rock and dust that follows
a highly elliptical orbit
• Close to the sun ice melts and creates a tail
• Dirty snowball
Oort Cloud
• Spherical region that surrounds
the solar system and extends half
way to the nearest star
Asteroid
• A small irregularly shaped rocky
object that orbits the sun
• The Asteroid Belt is between Mars
and Jupiter
Meteoroid – a sand grain-to boulder
size rocky body traveling through
space
Meteor – the rocky body enters
Earth’s atmosphere and is burned in
the mesosphere
Meteorite – the rock body hits
Earth’s surface