June 19, 2010

Partial Lunar Eclipse Appearing June 26

A partial lunar eclipse will take place on June 26 that will be visible from parts of North America, weather permitting.

The eclipse will take place as the moon crosses through the southern portion of Earth's shadow in the constellation Sagittarius.

The moon's diameter will be dramatically darkened at its peak, possibly tinged slightly with a mixture of faint orange and reddish hues.

There are filtered glows of innumerable sunsets and sunrises occurring around the rim of the Earth at the same time.  However, partial eclipses generally lack the colorful orange-red hues that a total lunar eclipse often shows.

No more than 53.7 percent of the moon's diameter dips inside the dark central core of the Earth's shadow, which is called the umbra.  That leaves almost half of the moon's disk in the shadow's outer fringe.

Some stages will not be visible because it will have disappeared below the west-southwest horizon, since the moon will set during the course of the eclipse.

The first bit of shading will become evident around 5:50 a.m. EDT when the moon's upper left portion has moved about two-thirds into the penumbra of the Earth's shadow.  The shading will darken for the next 25 minutes or so.

For about another 83 minutes the dark bite in the moon's edge enlarges until reaching maximum eclipse.  The umbra then extends 54 percent across the disk.

The moonset and sunrise lines at this point will have shifted west to run from Saskatchewan, Canada, to east Texas.

The next lunar eclipse is a total one later this year on the night of December 20-21, which will be visible from the Americas as well as western portions of Europe.


Image Caption: This image shows the last bit of light creeping away as the Moon slips completely into the heart of the Earth's shadow during the Lunar Eclipse on August 28, 2007. The blue color in this image is caused by the Earth's ozone layer, which gives our planet's shadow a turquise-colored fringe. This image of the Moon was taken by Brian Karczewski of Hemet, California. Credit: Brian Karczewski/SpaceWeather.com