In the Shadow of the Earth - Feb 21st Lunar Eclipse

For any newbies out there that want to know more, here is some information for Thursday's early morning Total Lunar Eclipse. It has been slightly edited from an article that was submitted to newpapers.

If you are one that likes to observe the Moon during the night, then get ready for a Total Lunar Eclipse on the night of Thursday February 21st. On this night, you will witness the Moon become blood red as it passes into the shadow of the Earth. The event will be observable without telescopes through most of western Europe and the Americas. Even though a Total Lunar Eclipse occurs twice a year, did you ever wonder how it occurs?

The Mechanics
In the better-known Total Solar Eclipse, a rare alignment of the Sun, Moon, and Earth occurs, where the Moon will completely block out the Sun’s light for a very small portion of the Earth’s surface. In a Total Lunar Eclipse, the opposite occurs, whereby the Earth comes between the Sun and the Moon. During any one calendar year, only 2 total lunar and 2 total solar eclipses will take place. However, not all of Earth can be witness to each event.

Things are not aligned up in a perfect X-Y linear development in our part of the Solar System. Earth is tilted in its orbit towards the Sun, and then, in a similar way, the Moon is tilted in its plane of orbit around Earth. Inevitably, though rarely, a perfect alignment does occur. This allignment is made even more dramatic during a Solar Eclipse when you consider the following piece of astronomical trivia: The Sun is almost 400 times further from Earth than the Moon is, and the Sun is almost 400 times larger than the Moon. Because these ratios are approximately the same, the size of the Sun and the Moon each as seen from Earth appear to be approximately the same when seen in the sky. Coincidence? Or a product of Intelligent Design? Who knows.

However, this quirk of physics does not entirely lead to as great a phenomenon during a Lunar Eclipse. The Moon is quite close to Earth, and also very small. Earth’s shadow is also very broad in this close distance that the Moon’s orbit occupies. Still, despite these less glamorous conditions, a Total Lunar Eclipse offers a completely different view of the Moon to be observed.


The Event Itself
(Timings given in this section should be taken with a plus/minus of 1.5 minutes depending upon your location in Ireland) First Contact occurs after midnight at 00:34hrs when the Moon ‘touches’ the outer shadow of Earth, called the penumbra. You will notice the lower left of the disc begin to darken, and gradually get larger across its surface. It will have a darkened grey appearance. This part is called a Penumbral Eclipse.


Then, it begins to enter the darkest part of Earth’s shadow, called the umbra, at 01:41hrs. Again, from roughly the same spot (lower left), the Moon will begin to take on a blood red appearance. This is referred to as (the start of) a Partial Lunar Eclipse.
Totality itself (Second Contact) occurs when all of the body of the Moon is encased inside Earth’s umbra, at 03:00hrs. From here, it will take the Moon approximately 52 minutes to pass through the umbra, with the darkest part seen at 03:26hrs.
It begins to come out of the umbra (Third Contact) at 03:52hrs. From there, it takes on the dark grey appearance again as it passes into the second penumbra.
The event then continues in reverse, and finishes at 06:17hrs when the last part of the Moon (Fourth Contact) leaves Earth’s shadow completely, and things get back to normal.


Observations
If you have a telescope or binoculars, then this is a good opportunity to observe the Moon in a new light. Craters and maria (‘seas’) appear different when they don’t have the bright rays of the Sun to cast peculiar shadows on the lunar surface. The red colour of the surface during Totality is actually caused by Earthlight passing through our atmosphere, and reflecting off the Moon’s surface. If the night is clear, the sudden darkness will also allow time to observe other heavenly treasures in the new-found darkness. During the entire event itself, if using optical equipment, you might even spot the Moon occult a background star, and for the time taken to observe the eclipse, see it reappear again later.

[END]


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Clear Skies,

Seanie.

thanks for the rundown Seanie. I see from Stellarium its going to be near Saturn, im looking forward to it. Just the time its at is a killer.

Just the time its at is a killer.

I know. Get this: I know it is on Thursday, but I was thinking Thursday night -> event starts at half past midnight Friday morning. So, what did Seanie do? He got Thursday night covered off work alright... Just the wrong night! Still, I finish my Wednesday night job at midnight, conveniently, so I will still be able to view it.

Seanie.

:oops:

I'm taking Thursday and Friday off, I had some holidays to burn anyway.
Lets all pray for a clear sky !.

Not looking good Dave (the weather)...............

Just the time its at is a killer.

I know. Get this: I know it is on Thursday, but I was thinking Thursday night -> event starts at half past midnight Friday morning. So, what did Seanie do? He got Thursday night covered off work alright... Just the wrong night! Still, I finish my Wednesday night job at midnight, conveniently, so I will still be able to view it.

Seanie.

:oops:

AAAAAAAHHHH *+%^!!!!

I did the same.

''%$% &%&^% &&&&*(())() (&*(**% ^'!!!!!''
Or something to that effect!

:roll: