Notices
Results 1 to 2 of 2

Thread: Moon movement - solar eclipse

  1. #1 Moon movement - solar eclipse 
    Forum Freshman
    Join Date
    Jul 2009
    Posts
    63
    Why does a solar eclipse "move" from West to East?

    Velocity of Moon's shadow is about 1 km/sec
    Velocity of Earth's rotation at equator is less than .5 km/sec
    http://www.physlink.com/Education/AskExperts/ae88.cfm

    So why doesn't the Moon always appear to travel from West to East, at about .5 km/sec?

    The Moon moves in its orbit about one diameter per hour to the East.
    http://cseligman.com/text/sky/moonmotion.htm
    This is equal to 13 degrees per day.

    If the Earth didn't rotate, the moon would be seen in its true West to East orbit.

    But the Earth rotates 360 degrees per day, making the Moon appear to travel from East to West.

    How does this agree with the answer about solar eclipse?

    George


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Freshman
    Join Date
    Jul 2009
    Posts
    63
    After reviewing this info several times, came to this conclusion:

    Moon's orbital velocity about 1 km/sec
    Earth's rotational velocity less than .5 km/sec

    The Moons velocity is required to travel 2,417,800 km in 27.3 days.
    The Moon's greater velocity is at a distance of 385,000 km from us, making the velocity appear much smaller.
    In 24 hours, the moon travels about 88,564 km, which is about 4% of its journey.
    From the Earth, this amounts to about 13 of 360 degrees.
    We don't easily realize this Easterly movement because Earth is rotating at a faster rate, making the Moon appear to travel East to West.

    Like you're on a fast merry-go-round, people on the ground appear in one direction, even tho some may be walking in the opposite direction.

    But in a solar eclipse, the Sun sheds light on the Moon's travel for several minutes as the shadow mimics the actual velocity and direction of the Moon.

    George

    ps. I find it amazing that light travels that far and still produces dependable shadows.


    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •