 The time it takes for light to travel from the sun to earth is 1 AU.  Light Year- The distance light travels in 1 year  Light Minute- The distance light can travel in 1 minute  Light Hour- The distance light can travel in 1 hour.

 The earth orbits in an ellipse! Not a circle!  It takes 365 day for the earth to revolve 1 time around the sun. We call 1 revolution 1 year!  Rotation is different from revolution!  It takes 24 hours to rotate 1 time. This is the same as 1 day!  All planets rotate and revolve.

 1 rotation Is equal to 1 day

 Isaac Newton explained that gravity is and inertia holds the planets in orbit around the sun.  Inertia is when an object in in motion until forced to stop.  Gravity depends on the distance and mass of the object. For example the earth has more gravity than the moon because the earth has more mass(size).

 The telescope was used to help prove that star patterens and constellations' existed along with proving the heliocentric model.  Constellations are stars that are in patterns.  The Hubble telescope is used to explore other planets and galaxies.

 A Telescope is an instrument that gathers electromagnetic radiation from objects in space and concentrates it for better observation.  Basically it takes the object and the space around it that your looking at and gathers it together so that you can see it better.

 Optical- these use light from objects to focus the object up close. Hubble is a optical telescope.  Refracting- A telescope that uses a set of lenses to gather and focus light from distant objects.  Reflecting- A telescope that uses a curved mirror to gather and focus light from distant objects.

 This telescope takes light and bends it before it reaches your eye. Two disadvantages of this kind of telescope is that images cant be totally focused and the size of the telescope is limited.

 Takes light and reflects it before reaching your eye. Most professionals us reflecting telescopes because they focus images better. Reflecting Telescopes can be real big or real small.

 Telescopes are put into space so that objects in space can be seen better.  The pollution in the air, humidity, and atmosphere make it harder for scientist to view space objects from earth.

 Constellation are sections of the sky that contain certain star patterns.  Depending the season, a constellation will change to different positions in the sky.  They will not change shape, just where they are located.