dipper@utastro.UUCP (Debbie Byrd) (05/18/85)
The moon's shadow falls on the Earth tomorrow. More on tomorrow's partial solar eclipse -- after this. May 18 A Partial Solar Eclipse The shadow of the moon falls on the Earth on Sunday. Observers on the far northern part of Earth have a chance to see a partial eclipse of the sun -- when the sun's light is blocked by the body of the moon. The moon casts a shadow that extends for hundreds of thousands of miles into space. Like all shadows, the lunar shadow falls away from its source of light -- the sun. Solar eclipses occur for earthlings when the moon travels between the Earth and sun -- and our planet brushes through the moon's shadow. An intersection of the Earth with the shadow of the moon doesn't happen every time the moon comes between the Earth and sun. The moon orbits the Earth at an angle to the Earth's orbital plane of the sun. The Earth intersects the lunar shadow only if our planet, the moon and the sun are in a true straight line. If you were out in space in the Earth's orbital plane -- looking edgewise into the plane -- and drew a straight line between the Earth and sun -- -- tomorrow when the moon passes between them it will be just slightly above that straight line. The southern edge of the moon's shadow will sweep across the northern top of our world. The lunar shadow that grazes Earth passes too far north to be seen by most of North America. But observers in Alaska -- who take special viewing precautions to protect their eyes -- can see a dark indentation in the sun's disc -- as the moon travels between us and our motherstar -- around midday on Sunday. Script by Diana Hadley. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin