|2015-4-04: Lunar Eclipse - April 4th, 2015 ⬅︎ |
|We were up at 3:30 AM for this Lunar Eclipse. The sky was fantastically clear but a frigid 36 degrees F.
With telescope, camera and computer set up, we watched until close to
What is a lunar eclipse? A lunar eclipse, like a solar eclipse, involves the perfect alignment of sun, earth
and moon. With a solar eclipse, the order is sun-moon-earth with the moon's relatively small shadow
falling on part of the earth. With a lunar eclipse, the order is sun-earth-moon with the earth's much larger
shadow falling on all or
most of the moon.
Earth's shadow actually has two parts -- the outer penumbra (which means 'almost shadow') and
the inner umbra (which means 'shadow'). The word umbrella comes from umbra.
The umbra is usually a deep red in color because it is
the light from the sun that glances through earth's atmosphere creating all the sunrises and sunsets at the
same time before coming out the other side. Cool!
You can see the gray penumbra and the red umbra in the diagram above.
This particular lunar eclipse had the top of the moon graze the boundary between the penumbra and the
umbra. So the part of the moon closest to the penumbra didn't turn as red and was much brighter than the
part of the moon deep within the umbra as our photo and diagram above shows. Because of this, the
moon didn't turn as dark red.
Did you see this eclipse? Either way, there is another one coming on September 27th and it will be easier
to view being in the early evening. Even better, the moon will go deep inside the umbra causing it to be a
more vivid red. Let's hope for clear skies!