Our Solar System

1
Our Solar System
2
Discovering Planetary Motion

• Early Greeks, such as Aristotle, believed that
  Earth was the center of our universe with the
  planets revolving around it.
• This idea is called the geocentric system of
  planetary arrangement.

3
Discovering Planetary Motion

• Copernicus had a different idea. After studying
  the night sky, he discovered that the planets,
  including Earth, travel in orbits around the sun.
• Copernicus ideas were supported by the
  observations of Galileo.
• Later, Johannes Kepler added that the orbits were
  not perfectly circular. In fact, he observed that
  the orbits are ellipses.

4
The Inner Planets

• They are the four planets closest to the sun.
• The inner planets, call the terrestrial planets,
  are smaller and have rocky surfaces.
• The inner planets include Mercury, Venus, Earth,
  and Mars.

5
Mercury

• Planet closest to the sun.
• About 1/3 the diameter of Earth.
• Looks like our moon, has many craters.
• Is very hot when facing the sun and very cold
  when facing away.
• Has a very thin atmosphere, practically airless.
  This explains the dramatic temperatures.

6
Venus

• Can be seen as a bright object in the western sky
  after sunset.
• Similar in size to Earth often called Earths
  sister or twin.
• Retrograde Rotation is from east to west
  (clockwise) opposite direction from Earths
  rotation.
• Very thick, cloudy atmosphere mostly carbon
  dioxide and sulfur.
• Very, very hot heat cannot escape!!
• Contains volcanic activity.
• Day LONGER than year!

7
Earth

• Life
• Liquid water
• Oxygen to breathe

8
Mars

• The red planet-iron oxide
• Atmosphere is mostly carbon dioxide.
• Has polar caps made of frozen carbon dioxide.
• Has seasons similar to Earths.
• Has two small moons.
• Shows evidence of flowing water sometime in its
  history (frozen now).

9
The Outer Planets

• The last four planets in our solar system (so
  far).
• Also known as the Jovian planets.
• Very large.
• Have multiple moons.
• Primarily composed of gases.
• Have deep gas atmospheres.

10
Jupiter

• The largest planet in our solar system.
• 11 times the diameter of earth.
• Atmosphere is mostly hydrogen and helium.
• Home of the Great Red Spot a swirling storm in
  the atmosphere.
• Has 18 counted moons Ganymede being the largest
  in the entire solar system. 4 are named-Io,
  Callisto, Europa and Ganymede.

11
Saturn

• Second largest planet.
• Has visible rings made of dust and ice.
• There are 7 major bands, but thousands of rings
  in all.
• Has more than 18 moons.

12
Uranus

• Rotates on its side.
• Called the Emerald planet.
• Has five large moons.
• Has very thin rings around it not as
  spectacular as Saturns.

13
Neptune

• 30 times Earths distance from the sun farthest
  planet.
• Contains visible clouds in its atmosphere.
• Has at least 8 moons.
• Largest moon is Triton.

14
Comets, Asteroids, and Meteors

• Our solar system is made up of much more than
  just the sun, planets, and moons.
• Comets, asteroids, and meteors are much smaller
  than planets.
• They do rotate around the sun in orbits slightly
  different than planets.

15
Comets

• Chunks of ice and dust.
• They orbit the sun in long, narrow ellipses.
• Due to the long orbital path, it takes comets
  several years to make one trip around the sun.
• Structure includes the head made up of the
  nucleus and the coma and the tail made up of
  particles released from the head.
• The tail of a comet points away from the sun.

16
Asteroids

• Small, rocky objects rotating around the sun.
• Most are found in the space between Mars and
  Jupiterthis area is called the asteroid belt.

17
Meteoroids, Meteors, and Meteorites

• Chunks of rock or dust that typically come from
  comets or asteroids.
• Meteoroids chunks in space.
• Meteors chunks that enter Earths atmosphere
  and produce a streak of light as it burns in the
  atmosphere.
• Meteorites chunks that make it through the
  atmosphere and actually hit Earths surface.

18
Light Year

• The distance light travels in a year
• About 9.46 trillion kilometers

19
Parallax

• An apparent shift in the position of an object
  when view from different locations.
• A method used to determine a stars distance from
  the earth.

20
The Big Bang Theory

• Just what is the Big Bang theory of the origin
  of the universe?
• One scientist summed it up "The explosion from
  zero volume at zero time of a corpuscle of energy
  equivalent to the mass and radiation that now
  constitute the Universe."

21
Sowhat does that mean?

• That everything we now see or know about was once
  compacted into an unimaginably small blip that
  suddenly expanded in a huge explosion that
  created the very space and time it was expanding
  into
• The Big Bang is a process of expansion in our
  universe that is still active today
• The Big Bang theory holds that hydrogen and
  helium were the first elements created when the
  universe was formed.