October 2014 Lunar Eclipse!

Hello all! We have another fantastic astronomical phenomenon occurring tomorrow morning: a complete lunar eclipse! I will be waking up early to see it, and we should finally have decent clarity in the sky to actually see it! If you guys recall, earlier this year when we had a complete lunar eclipse, the skies were overcast here on the east coast and it was essentially invisible. 

What is a Complete Lunar Eclipse?

A complete lunar eclipse is when the moon is completely in the Earth's shadow which is cast by the Sun. When the Sun, the Earth, and the Moon are completely in line with the Earth in between the Sun and the Moon, also called syzygy which is the Greek word meaning "being paired together", the Earth casts a shadow giving the Moon a red tint. Why the red tint? Physics, my dear Watson. When direct sunlight is no longer able to reflect off of the Moon, the only light reaching the moon is the longwave red and orange light refracted by the Earth's atmosphere. This is why the moon appears to have a reddish/brownish coloration to it. The term for this coloration is "Earthshine".

When Will We be Able to See It?

In Raleigh, we will be able to see the Lunar Eclipse between about 4:15 am and 7:15 am. The maximum eclipse will occur at approximately 6:55 am according to astronomers. For best visibility, try to get to the roof of a building, the top of a hill, or a high-level window to get above the tree-line. I will be at Hunt Library myself to witness this annual event. Below is a chart which I found online with a full description of events:

Event	UTC Time	Time in Raleigh*	Visible in Raleigh
Penumbral Eclipse begins	Oct 8 at 8:17 AM	Oct 8 at 4:17 AM	Yes
Partial Eclipse begins	Oct 8 at 9:18 AM	Oct 8 at 5:18 AM	Yes
Full Eclipse begins	Oct 8 at 10:27 AM	Oct 8 at 6:27 AM	Yes
Maximum Eclipse	Oct 8 at 10:55 AM	Oct 8 at 6:55 AM	Yes
Full Eclipse ends	Oct 8 at 11:22 AM	Oct 8 at 7:22 AM	No, below horizon
Partial Eclipse ends	Oct 8 at 12:32 PM	Oct 8 at 8:32 AM	No, below horizon
Penumbral Eclipse ends	Oct 8 at 1:32 PM	Oct 8 at 9:32 AM	No, below horizon

* The Moon is below the horizon in Raleigh some of the time, so that part of the eclipse is not visible.

This table was found at http://www.timeanddate.com/eclipse/lunar/2014-october-8

Lunar Eclipse Terminology

We have already learned about syzygy and Earthshine, but what else is there to learn about lunar eclipses? The Earth's shadow actually has three different parts: the Penumbra, the Umbra, and the Antumbra. The Penumbra is the outer part of the Earth's shadow. When the moon crosses through the Earth's Penumbra, it is given a slight reddish/orange coloration but still appears relatively bright in the sky. The image on the right is a picture of a partial lunar eclipse. The Umbra is the darker central part of the Earth's shadow. During the transition phase into the Full Eclipse, the Moon will appear dark with a white edge and the opposite edge appearing red. When the moon is at Maximum eclipse, it will appear entirely red, and the red portion, which is the deepest portion of the Earth's shadow, is called the Umbra. The Antumbra is the portion of the Earth's shadow beyond the moon. It is not actually visible because of the massive shadow that the Earth casts, but is much more visible during a Solar Eclipse. During a solar eclipse, when the moon is far enough away from Earth that the actual shadow does not reach the Earth, the axis of the Moon's shadow continues to portray a partial shadow on the Earth. 

I hope all of you can go out and witness the Eclipse!

http://www.timeanddate.com/eclipse/total-lunar-eclipse.html

http://www.timeanddate.com/eclipse/annular-solar-eclipse.html

https://www.google.com/search?q=lunar+eclipse&espv=2&biw=2133&bih=1008&source=lnms&tbm=isch&sa=X&ei=rhg0VIbVDI6lyATshYLoCA&sqi=2&ved=0CAcQ_AUoAg&dpr=0.75