APOD: A Lunar Eclipse on Solstice Day (2010 Dec 20)

[neufer]

"There IS a lunar eclipse on the solstice. That is a true statement around the world." Actually it's a wrong statement everywhere because the difference in time is 15 hours, more than half a day! It's one of those moderately rare cases where both events happen within a 24-hour period, which means that for some timezones it's on the same calendar day.

Last time I checked, a day was still 24 hours, and 15 was still less than 24.

I was a little slow to catch on to the interesting point that Fischer is alluding to:

When the December 21, at 08:17 am UTC total eclipse takes place it will still be December 20th in Hawaii & Alaska.
When the December 21, at 23:38 pm UTC solstice takes place it will be December 22th for half of the globe.

So what does APOD's "A Lunar Eclipse on Solstice Day" really mean?

Should it really have been: "A Lunar Eclipse on Solstice Day for many"
or: "A Lunar Eclipse within 24 hours of Solstice" (my preference)

I wonder if the winter solstice of 1387 actually took place during the lunar eclipse
rather than simply within 24 hours (or on the same day for parts of the northern hemisphere).
(The NASA eclipse website is swamped so will have to figure this all out later.)

Which happens to be the area of the world where the eclipse is seen best, i.e. in a dark sky: So go observe the nice show and stop loading it with largely meaningless numerology (I even saw a Canadian paper interview a witch about that - no kidding)!

Where, please, did I load "it" up with numerology, meaningless or otherwise?
This is the first post in which I've mentioned or referred to any numbers at all.

Fischer is talking about APOD being to parochial.

[mexhunter]

NOVA Secrets of Stonehenge

I tried several times and get the same result.

Click to view full size image

Either way, I want to say that the day I saw the place I felt a great magnetism, there is none.

Click to view full size image

http://www.astrophoto.com.mx/index.php?
More or less a few hours should not be a problem.
Here the weather is splendid, try to enjoy it.
Greetings
César

[owlice]

neufer, I caught his point; it just struck me as splitting hairs. If I'm reading an Australian website, I don't get annoyed when it refers to the December solstice as the start of summer. Okay, so apparently some people do -- which strikes me as a different kind of parochial that is even worse than that Daniel Fischer is railing against.

[neufer]

neufer, I caught his point;

Well, you were quicker than I was on that.

it just struck me as splitting hairs.

It forces one to think; which is always a good thing in my opinion.

What does it even mean when APOD states: "This solstice eclipse is the first in 456 years."

If I'm reading an Australian website, I don't get annoyed when it refers to the December solstice as the start of summer.

Okay, so apparently some people do -- which strikes me as a different kind of parochial that is even worse than that Daniel Fischer is railing against.

Engraving of Will Sommers by Francis Delaram c. 1615-24
William Sommers made a number of appearances
in 16th and 17th century drama and literature:
for example, Thomas Nashe's Pleesant Comedie called
Summers last Will and Testament (play first performed
in 1592, published in 1600), and a popular account, A
Pleasant Historie of the Life & Death of William Sommers.

<<William 'Will' Sommers (or Somers) (died June 15, 1560) was the best-known court jester of Henry VIII of England. Born in Shropshire, Sommers came to the attention of Richard Fermor, a merchant of the staple at Calais, who brought him to Greenwich in 1525 to present to the King. Impressed by Sommers' sense of humour, Henry promptly offered him a place at court. He was soon in high favour with the King, whose liberality to him is attested by the accounts of the royal household. Sommers remained in the King's service for the rest of Henry's life; in the King's later years, when he was troubled by a painful leg condition, it was said that only Sommers could lift his spirits.

The jester was also a man of integrity and discretion; Thomas Cromwell appreciated that he sometimes drew the King's attention to extravagance and waste within the royal household by means of a joke. After Henry's death, Sommers remained at court, eventually retiring in the reign of Elizabeth I. He was probably the William Sommers whose death is recorded in the parish of St Leonards, Shoreditch, on June 15, 1560.

Court jesters were permitted familiarities without regard for deference, and Sommers possessed a shrewd wit, which he exercised even on Cardinal Wolsey. However, he did occasionally overstep the mark. In 1535, the King threatened to kill Sommers with his own hand, after Sir Nicholas Carew dared him to call Queen Anne "a ribald" and the Princess Elizabeth "a bastard" .

Robert Armin (writer of Foole upon Foole, 1600) tells how Sommers humiliated Thomas, the King's juggler. He interrupted one of Thomas' performances carrying milk and a breadroll. Will asked the King for a spoon, the King replied he had none and Thomas told him to use his hands. Will then sang:

• 'This bit Harry I give to thee
  and this next bit must serve for me,
  Both which I'll eat apace.
  This bit Madam unto you,
  And this bit I my selfe eate now,
  And the rest upon thy face.'

He then threw the milk in his face, ran out, and Thomas was never at court again.

Sommers also used his influence to compensate an uncle who had been ruined by an enclosure of common land, though it took a very subtle appeal by Sommers to Henry.

In Thomas Wilson's Arte of Rhetorique (1553–60), Will is quoted telling the financially hard-up King: "You have so many Frauditors [Auditors], so many Conveighers [Surveyers], and so many Deceivers [Receivers] that they get all to themselves."

Sommers is believed to be portrayed in a painting of Henry VIII and family at the Palace of Whitehall, completed around 1544-5 by an unknown artist. He also appears with Henry VIII in a psalter which belonged to the King and is now in the British Museum. A new picture in which he appears was discovered in 2008 at Boughton House, Northamptonshire.

Under Mary I Will's role was mainly ceremonial, and as a sidekick to Mary's personal fool, Jane. Will was reputed to be the only man who made Mary laugh, apart from John Heywood. Will's last public event was the coronation of Elizabeth I.>>

[owlice]

What does it even mean when APOD states: "This solstice eclipse is the first in 456 years."

It means, since you are currently at 4789 posts, we're missing a 2 and a 3 and have an extra 4.

[NoelC]

Think globally, watch eclipses locally.



-Noel

[NoelC]

it will be December 22th for half of the globe.

http://www.amazon.com/Our-Tooth-Story-T ... 0396064728

My very first neuferkonnection.

-Noel

[biddie67]

My lawn chair is in a good position in the yard, my alarm clock is set and the alarm turned up high, my coat, hat, boots and gloves are set out, the flashlight is right beside them - all at the ready - bring on that solstice lunar eclipse .....

[neufer]

What does it even mean when APOD states: "This solstice eclipse is the first in 456 years."

It means, since you are currently at 4789 posts, we're missing a 2 and a 3 and have an extra 4.

Num num num...

[StarryEyeGuy]

So Chester went looking for "an eclipse matching the same calendar date as the solstice"? 2029 clearly qualifies as a hit for Asia with its billions of people where the eclipse and solstice both fall on their calendar date of December 21. All I'm asking that people make precise statements, like "mid-eclipse and solstice on the same UTC day" or such, and take into consideration that the place on Earth where they are sitting isn't special on this planet. Even if it's USNO or NASA HQ ...

I'd like the chance to qualify my statement, since, as is the case with many things these days, stuff gets lost in the cyberspace shuffle...

In answer to a growing number of public inquiries and citations of various dates of the "last solstice total lunar eclipse", I decided to look for the previous such occurrence of the time of mid-eclipse and the solstice sharing the same calendar date based on Terrestrial Dynamical Time, a time-scale that more-or-less corresponds today with UT1 (but *not* UTC!). The only such occurrence of a total lunar eclipse falling under those circumstances was 1638 DEC 21, and the next one will be 2094 DEC 21. While it is true that the 2029 eclipse will occur on the 21st local time in a large segment of the world, and the last stages of the umbral phase occur in the first few minutes of the 21st in UT1, the mid-eclipse still occurs on the 20th at 22:42 UT1. Close, but no cigar. There has to be a single reference frame for these events, especially since there are 37 different time zones observed around the world today. Which is a pretty good trick, considering there are only 24 hours in a day.

Actually I'm still puzzling over the "456 year" statement. That would point to the lunar eclipse of 1554 DEC 9. Not only was this 3 days off from the solstice (which occurred on DEC 12), it was also a partial eclipse. In trying to run this one down I found that it was referenced to last Saturday's Drudge Report, which cited a Montreal newspaper article on how Wiccans were going to celebrate this year's eclipse and solstice. The paper, in turn, referenced NASA, but didn't specify exactly *where* in NASA. Damn...there goes my confidence in Matt Drudge!!

For those who'd like to check my sources, I used Jean Meeus' "Astronomical Tables of the Sun, Moon, and Planets" for the solstice times. For the eclipses I used the 5000-year lunar eclipse table on Fred Espenak's website at http://eclipse.gsfc.nasa.gov/eclipse.html. When I came across potential matches I further checked the timings using the JPL Horizons website. Given my search/match criteria, 1638 was the last, 2094 is the next, and after that I don't really care since my odds of seeing it are pretty slim ...

Cheers,

Geoff Chester

[orin stepanek]

Oh my! The eclipse is past my bed time. http://www.kansan.com/news/2010/dec/20/ ... e-tonight/
I'll have to see the pictures of it afterwards; unless mother nature calls in the middle of the night.

[zloq]

I posted on this some time ago but it seems to have been lost in cyberspace. I agree that the novelty of this event lies in its having two things fall on the same calendar date. Calendar date is defined locally - and is perfectly valid even in this astronomical context. If two events straddle midnight in your local time - even with daylight savings at work if it is - then for you it is on two different calendar dates. For Hawaiians the eclipse happens the day before solstice day.

Meeus mentions a similar lunar novelty in his Morsels book. The question is, what months contain 5 lunar phases. Lunar phase is well defined astronomically, but "month" depends on whether you use UT or local time - since it affects the start and end moments of the month. You can play the game either way, and he makes no pedantic insistence that it must be specified in UT.

I see three ways to play this solstice/eclipse game. 1) The two things happen on the same date, UT 2) The two things happen on the same date some place on the Earth in its local time, and 3) The two things happen within 24 hours of each other. Of these, (2) is most relevant to people going about their lives because the calendar on their wall is in local time - not UT. Option (3) is a real snoozer.

A side point is that the solstice is defined in terms of the apparent ecliptic longitude of the sun - not its declination. The two things are slightly different.

zloq

[owlice]

What does it even mean when APOD states: "This solstice eclipse is the first in 456 years."

It means, since you are currently at 4789 posts, we're missing a 2 and a 3 and have an extra 4.

Num num num...

And we still don't have Yahtzee.

[neufer]

So Chester went looking for "an eclipse matching the same calendar date as the solstice"? 2029 clearly qualifies as a hit for Asia with its billions of people where the eclipse and solstice both fall on their calendar date of December 21. All I'm asking that people make precise statements, like "mid-eclipse and solstice on the same UTC day" or such, and take into consideration that the place on Earth where they are sitting isn't special on this planet. Even if it's USNO or NASA HQ ...

I'd like the chance to qualify my statement, since, as is the case with many things these days, stuff gets lost in the cyberspace shuffle...

In answer to a growing number of public inquiries and citations of various dates of the "last solstice total lunar eclipse", I decided to look for the previous such occurrence of the time of mid-eclipse and the solstice sharing the same calendar date based on Terrestrial Dynamical Time, a time-scale that more-or-less corresponds today with UT1 (but *not* UTC!). The only such occurrence of a total lunar eclipse falling under those circumstances was 1638 DEC 21, and the next one will be 2094 DEC 21. While it is true that the 2029 eclipse will occur on the 21st local time in a large segment of the world, and the last stages of the umbral phase occur in the first few minutes of the 21st in UT1, the mid-eclipse still occurs on the 20th at 22:42 UT1. Close, but no cigar. There has to be a single reference frame for these events, especially since there are 37 different time zones observed around the world today. Which is a pretty good trick, considering there are only 24 hours in a day.

Actually I'm still puzzling over the "456 year" statement. That would point to the lunar eclipse of 1554 DEC 9. Not only was this 3 days off from the solstice (which occurred on DEC 12), it was also a partial eclipse. In trying to run this one down I found that it was referenced to last Saturday's Drudge Report, which cited a Montreal newspaper article on how Wiccans were going to celebrate this year's eclipse and solstice. The paper, in turn, referenced NASA, but didn't specify exactly *where* in NASA. Damn...there goes my confidence in Matt Drudge!!

For those who'd like to check my sources, I used Jean Meeus' "Astronomical Tables of the Sun, Moon, and Planets" for the solstice times. For the eclipses I used the 5000-year lunar eclipse table on Fred Espenak's website at http://eclipse.gsfc.nasa.gov/eclipse.html. When I came across potential matches I further checked the timings using the JPL Horizons website. Given my search/match criteria, 1638 was the last, 2094 is the next, and after that I don't really care since my odds of seeing it are pretty slim ...

Cheers,

Geoff Chester

That was extremely interesting Thanks, Geoff.

I also humbly concede that Daniel Fischer's 2029 total eclipse within
24 hours of Solstice is equally interesting so far as I am concerned
(; despite what zloq has to say... and I am hoping to live to that one):

On APOD you wonder about the date of the next solstice lunar eclipse. It depends on how long the time interval to midwinter may differ (time zones on Earth, that is) and how long totality will last. I would suggest a difference of no longer than 24 hours, so that the coincidence might happen on the same calendar date of any of our timezones. But even if we take into account the severe restriction of the calendar date in Universal Time (UT), we will experience another solstice total lunar eclipse a few years before the end of this very century on 21 December 2094, as already observed by others in this discussion list:

Code: Select all

Year   Mid totality   Solstice    Duration of totality

2029    20.94 Dec.    21.60 Dec.   56 minutes
2094    21.83 Dec.    21.37 Dec.   96 minutes

[zloq]

I think as long as the times for the 2029 event are correct, it looks fine as an eclipse that happens on the date of solstice. You just have to go east a bit from Greenwich so that totality happens the next day - and it will be the same date as solstice there. You just can't go so far that solstice wraps into the next day. Not only does it 'happen' east of Greenwich - but they will have a good view of it.

I thought about this some more in terms of the "less than 24 hour separation" and I think it boils down to this. Assuming normal timezones and allowing for dateline behavior, as long as the two events are less than 23 hours apart, there will always be a place where they happen on the same date. That date may be different from the UT date, but it's still the same calendar date at that location.

It gets complicated when the separation is 23-24 hours. In that case, the two events cannot straddle an hour - i.e. the earlier one has to happen in an earlier fraction of an hour than the later one. Otherwise there is no place where both happen on the same date.

An example is 12:55 a.m. for the first one and 12:05 a.m. the next day for the later one. Even though they are less than 24 hours apart, you can't find a timezone where both happen on the same date.

Conversely, the two events could be a microsecond apart and, as long as they straddle an hour, there will be a location where they happen on different dates.

zloq

[ctinehallowell]

Well, on the date of my twelfth birthday, we experienced Syzygy. So that must mean I’m really something special! (It may also be giving away too much information, anywho…) Most likely, the twelfth anniversary of my birth and the planets being on the same side of the sun was likely coincidence.

I have a middle-of-the-road opinion about the Eclipse/Solstice debate.
I think it’s kinda cool that the two happened close together. But it’s all arbitrary, in my humble opinion, the measurement of time in general.
For example, a calendar had to start at some point. But wasn't the begining of the modern calendar arbitrary? (make sure you consider our insignificance in the universe). Wasn’t the start of the new millennium (now I just opened up the debate about when that actually began) special to people in the same kind of relative way?
In which time zone is the Armageddon supposed to occur in 2012?
What if our measure of days was more accurate? Which day would it be?
When did time really begin?
We have a much larger chance of being wrong than correct.
It’s fun, but it’s a bit irrational to think that any particular measurement of linear time is more special than another.
That being said, was it the solstice or not? No one knows for certain.

I do think that some people in North America forget about the rest of the world and are thoughtless at times. But then there are some out there that are a little touchy. In any case, most humans can’t be correct 100% of the time. And I don’t think this was an attempt to mislead.

It’s been fun reading the debate. I find it all amazingly wonderful and utterly meaningless.

[sea otter]

What if our measure of days was more accurate? Which day would it be?

Hmm. maybe today would be yesterday and tomorrow would be happening right now. Who can really say for sure?

We have a much larger chance of being wrong than correct.

from another thread
Neil deGrasse Tyson says "Its' all bad because we're human"

That being said, was it the solstice or not? No one knows for certain.

If you record the time of sunrise and sunset each day over a year's time,and then review your data, you may be able to pinpoint both solstices and both equinoxes.
These special days generally happen on the 21st day of the 3rd 6th 9th and 12th months (give or take a day or two here or there).

[zloq]

This eclipse had a novelty in that the calendar date of the eclipse wasn't close to - it was identical to - the date of solstice in some time zones. I think this is slightly interesting but definitely not remarkable as described in today's apod.

The eclipse was reported as rare, special, and worth watching because of this coincidence. I even saw it described as a "rare full moon total eclipse."

Along with these reports are descriptions of what solstice means, in terms of the sun being lowest and/or standing still in the sky. And the exact moment of solstice is provided.

All these times and terms ultimately have meaning somehow, particularly when you cite an exact moment of an astronomical event, or you say the two "dates" are identical. So it's good to be clear about exactly what is going on - even if the coincidence isn't very significant.

Although solstice historically refers to the sun standing still at its highest or lowest declination, in fact the moment cited as solstice is based on the sun's apparent ecliptic longitude of 90 or 270. At the moment of astronomical solstice, the true declination of the sun is not at its extreme. And for a given location on earth, the sun wobbles up and down in the sky as the earth rotates due to changing parallax - so the moment of extreme declination will be many hours off from solstice for a given observer. In practical terms this is irrelevant - but when the exact moment of solstice is cited, along with the extreme-dec definition of solstice - the two are incompatible.

As for dates being the same - that will always depend on what timezone the date refers to. Assuming two events (a "close pair") fall randomly in a 24 hour window, 1/48, or 2% of them will have the same date in all time zones on earth. 2% of them will not have the same date in any time zone even though they are less than 24 hours apart. The rest, or 96%, will have some time zones with the same date, and others with different dates.

When is the next eclipse with the same date as a solstice in all time zones? It's when they happen within one hour of each other, and both events fall in the same numerical hour. Now that would be rare - but not particularly significant either. Even rarer is an eclipse where the date in each time zone is the same for all time zones. I think that both events have to happen between 11 and 12h UT, ignoring daylight savings. If the two happen randomly within 24 hours of each other, only 0.17% of those close pairs will have this property.

zloq