A Partial Solar Eclipse for Christmas

CHRISTMAS will be extra special this year. Weather permitting, people all across North America will be able to watch the Moon glide across the low December Sun, creating a partial solar eclipse. This event will be visible throughout nearly all the inhabited parts of North America (except Alaska and the Yukon), as well as from most of Mexico and the Caribbean.

Click the picture to see a timetable of the eclipse.

How deep the eclipse will get also depends on where you are. As seen from California, Mexico, and the Caribbean, the Sun will appear only slightly dented at most. The eclipse will grow deeper, with the Sun turning into a fat crescent, for the Northwest through the central states to the Southeast. The narrowest, most dramatic crescent Sun awaits Christmas skywatchers in the Upper Midwest, the Great Lakes region, the Northeast, and all of eastern Canada. Here the light may be dimmed enough to give the winter landscape a slightly eerie cast, and winds may whip up as the partial loss of sunlight adds to the December chill.

Here is a timetable for the eclipse's beginning, middle, and end.

Beginning: 11:09 A.M.          Middle: 12:47 P.M.           End: 2:20 P.M.
 

It may look something like this: Right: On May 30, 1984, Maurizio Eltri captured this view of the partially eclipsed Sun shortly before it set in the west over Venice, Italy. Click on image for larger view. © 1984 Maurizio Eltri.

 

An eclipse of the Sun (or solar eclipse) can only occur at New Moon when the Moon passes between Earth and Sun. If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or 'eclipsed' by the Moon.At least twice a year, the geometry lines up just right so that some part of the Moon's shadow falls on Earth's surface and an eclipse of the Sun is seen from that region.

The Moon's shadow actually has two parts:

Penumbra - Faint outer shadow; partial eclipses are seen from within this shadow.

Umbra- Dark inner shadow; total eclipses are seen from within this shadow.

When only the Moon's penumbral shadow strikes Earth, we see a partial eclipse of the Sun from that region. Partial eclipses are dangerous to look at because the un-eclipsed part of the Sun is still very bright. You must use special filters or a home-made pinhole projector to safely watch a partial eclipse of the Sun

How to watch an eclipse safely
This information is from Sky and Telescope
Solar Eclipsses for Beginners