October Eclipses

[PakledHostage]

For anyone who's interested, there are two eclipses coming up in October. The first is a total lunar eclipse and the other is a partial solar eclipse. Both are visible from much of North America.

The total lunar eclipse occurs on October 8th, reaching greatest eclipse at 10:55 UT.

The partial solar eclipse occurs 2 weeks later (+1 internet cookie if you can explain why) on October 23rd, reaching greatest eclipse at 21:45 UT.

[Alshain]

if you can explain why a solar eclipse occurs? Because the moon passes between the sun and the earth, blocking the sun's view.

EDIT: Or did you mean why is it two weeks later. That's because the moon takes 27 days to orbit the earth, so the earth comes between the sun and the moon to create a lunar eclipes and half the moons full orbit later, the moon comes between the sun and the earth.

Edited September 29, 2014 by Alshain

[Dkmdlb]

Because the moon takes 28 days to orbit earth. Thus, whenever the earth is directly between the sun and moon, 28/2 days later the moon will be halfway around its orbit and between the earth and sun.

Yay for internets.

[Megalodon 720]

Well, I live in East Anglia so... no eclipses any time soon

[Aethon]

Hey Packled . Nice thread.

In the hopes of a cookie: The orbits of bodies IRL is somewhat variable. Different inclinations, eccentricities, orbital speeds throughout the month/year can be quite confusing, however patterns do occur.

If a solar eclipse occurs at one new moon, which must be near one of the nodes, then when the moon reaches the opposite node (full moon) it may or may not move through the Earth's shadow, because the Sun and Moon will have moved about 15 degrees relative to the nodes. When it does it is called a (lemme get this right) syzygy (isn't that Scott Manleys' EVE online handle?).

The period between these two eclipses is half a synodic month (about 14 days) and is called a fortnight eclipse cycle.

We're actually in the middle of a tetrad lunar eclipse cycle. With lunar eclipses to occur in April and October of 2015.

Ninjas begone!

Edited September 29, 2014 by Aethon

[PakledHostage]

While we're on the topic of the predictability of eclipses, here's a cool YouTube video about some guys who built a replica of the Antikythera Mechanism out of Lego. The Antikythera Mechanism dates from about 100 BCE and is believed to be a mechanical computer that was designed to predict eclipses.

[Aethon]

Super cool. That's actually the best explanation of the workings of the Mech. that I've ever seen. Thanks for helping pass the time 'till update.

As a collector of ancient Greek coins, I LOVE ancient Greek history and own some chunks of Greek metal that are older than the Antikythera mech., but none as amazingly functional. Fascinating!

I've read about some recent plans to dive on the wreck again and would love to hear the results of this. The ship that sunk with the Antikythera mech. on board was LADEN with Greek plunder and on it's way back to Rome when it sunk. It has given us some of the only examples of bronze Greek sculpture that survive to this day.

https://www.google.com/search?q=antikythera+shipwreck+sculptures&espv=2&biw=1218&bih=663&tbm=isch&tbo=u&source=univ&sa=X&ei=WJApVM-2Oor3yQTN3IKoAQ&ved=0CBwQsAQ

One can only imagine what else remains in Poseidons' domain, including other parts of the mechanism.

Edit- http://phys.org/news/2014-09-divers-ancient-shipwreck.html

Edited September 29, 2014 by Aethon

[Skyler4856]

Huh, hopefully it isn't cloudy, otherwise Id get a nice view

[Tommygun]

Wow, I had no idea Legos had been around that long.

Well I live along the coast of California, so far every eclipses but one in the last 25 years has been blocked by coastal clouds.

So will see....or not.

[cantab]

Britain here as well. We do seem to be in a (lunar) eclipse drought these past few years, why is that?

[YNM]

The partial solar eclipse occurs 2 weeks later (+1 internet cookie if you can explain why)

Because the eclipses happen when the moon is near ascending and/or descending node (wrt ecliptic), and 14 days is approx. the time it takes half a synchronous orbital period ?

Britain here as well. We do seem to be in a (lunar) eclipse drought these past few years, why is that?

Look at when was the last time an eclipse happened within 0 degree longitude. Saros cycle makes it that eclipses always moving approx. 120 degrees west for every eclipse within the cycle. Calculating for latitude is harder.

[KerbMav]

While waiting for my turn to get my hair cut I read that March'15 there will be an eclipse in/above/visible from Germany - and no one can say for sure the sudden drop in power generation from solar plants will collapse the power grid or not - they seem to suggest to not take the solar plants online that day at all.

[PakledHostage]

While waiting for my turn to get my hair cut I read that March'15 there will be an eclipse in/above/visible from Germany - and no one can say for sure the sudden drop in power generation from solar plants will collapse the power grid or not - they seem to suggest to not take the solar plants online that day at all.

That seems a bit alarmist to me. Seret? What do you think? You seem to know a thing or two about solar power generation? That eclipse is only going to be partial over Germany. Roughly magnitude 70%-80%.

Edited September 30, 2014 by PakledHostage

[cantab]

Dropping to 20% of normal sunlight is going to reduce generation capacity, but I very much doubt it will cause any real issues. After all a solar eclipse is the ultimate in predictable events and will give a very gradualy dip in generation capacity. Other plants will be brought online to fill the gap, or power could be imported from neighbouring countries.

[Tommygun]

So I got out to see the Lunar eclipse tonight and what did I see:

A big fat NOTHING!, Ain't got squat, Big Fat Goose Egg , blank , bupkis, barren, zero, diddily squat , duckegg , empty, freshout, gone, gooseegg, nada, naught, nein, nichts, nil, non, none, nonentity, nonexistence, not-a-thing, nothingness, nought, null, nuttin', scratch, skunked, squat, void, wash-out, zero, zilch, zip, zippo.

Damned coastal clouds.............

[Mitchz95]

I was one time zone too late to see it.

[Dominatus]

You fewls! The answer to the question is a simple one: because that's the way the Magratheans- specifically Deep Thought- designed the earth. To ask why is like trying to find the question to suit the answer about life, the universe, and everything, and answer which is 42 but makes no sense without the question.

[SuperFastJellyfish]

Suburb of Chicago here. I saw about 10 minutes of totality before it was obscured by clouds. It never gets old. What I really can't wait for is the total solar eclipse that will pass through Kentucky-ish in 2017. I'll definitely be there for that bad boy!

[Spark Plug]

I live in the Philippines and was able to observe the partial eclipse tonight, starting at about 7:45 pm Philippine Standard Time (11:45 UT, is that a correct cnversion?). After barely one hour, the shadow of the Earth was almost completely gone from the surface of the moon. Some clouds appeared at this point and so I had to pack up my stuff.

It was wonderful and amazing! This is my first eclipse, as far as I can recall. I also made sketches of my observations for the first time, after owning a (amateur and low-power) telescope for some 5 years now. Maybe I'll scan and post those sheets later.

[PakledHostage]

@Tommygun: I'm with you... Stupid clouds. It was clear up until about 2 hours before first contact with the Earth's penumbra but then the fog rolled in. I was able to get one photo with the moon partially in the penumbra and partially in the umbra but it doesn't look like much. It is obscured by fog and you can't see any of the red color. Maybe I'll post it later today.

@SuperFastJellyfish: I plan on driving to Oregon or Idaho for that one too. Somewhere where it is likely to be clear. I had the good fortune to see a total solar eclipse about 15 years ago and it was such an amazing experience that I'd love to see another one. Everything went quiet during totality. The street lights came on, the birds stopped singing. It was kind of creepy actually. And I remember there being a lot of towering cu's around. Watching the edge of the moon's shadow approach at thousands of kilometers per hour from off in the distance at the end of totality (we could see it coming from the light reflected on the CB's in the distance) made me feel the smallest and most insignificant that I have ever felt.

[Tw1]

Here are some of my best photos from last night.

It was cloudy most of the time, apart from this.

[Aethon]

Nice Tw1. Thanks for sharing!

[YNM]

Can't observe the full eclipse - weather reasons (as well as horizon problems had it been not cloudy)...

Saw several images from friends at other places through (including the partial).

[Aethon]

Here's an interesting view of our recent lunar eclipse as seen by the MESSENGER spacecraft, currently in orbit of Mercury.

http://www.universetoday.com/115218/watch-the-blood-moon-eclipse-from-mercury/#more-115218

[PakledHostage]

Looks like it is going to be cloudy for me during the partial solar eclipse tomorrow, but hopefully some of you here in North America will be able to see it. I'll bring my camera and ND filters to work just in case but I might have to watch it on Slooh...