Starship Asterisk*

A Lunar Eclipse on Solstice Day

Explanation: Sometime after sunset tonight, the Moon will go dark. This total lunar eclipse, where the entire Moon is engulfed in the shadow of the Earth, will be visible from all of North America, while the partial phase of this eclipse will be visible throughout much of the rest of the world. Observers on North America's east coast will have to wait until after midnight for totality to begin, while west coasters should be able to see a fully darkened moon before midnight. Pictured above is a digital prediction, in image form, for how the Moon and the surrounding sky could appear near maximum darkness. Rolling your cursor over the image will bring up labels. Parts of the Moon entering the circle labeled umbra will appear the darkest since the Sun there will be completely blocked by the Earth. Parts of the Moon entering the circle labeled penumbra will be exposed to some direct sunlight, and so shine by some degree by reflected light. The diminished glare of the normally full Moon will allow unusually good viewings of nearby celestial wonders such as the supernova remnant Simeis 147, the open star cluster M35, and the Crab Nebula M1. By coincidence this eclipse occurs on the day with the shortest amount of daylight in the northern hemisphere -- the Winter Solstice. This solstice eclipse is the first in 456 years, although so far it appears that no one has figured out when the next solstice eclipse will be.

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Solstice Lunar Eclipse
http://asterisk.apod.com/vie ... 29&t=22335

Another time traveler, image taken prior to the event

Pink Floyd wrote:There is no dark side of the moon really. Matter of fact it's all dark.

Pink Floyd: The Dark Side of the Moon

• Part 1: http://www.youtube.com/watch?v=QmjS37zDbPY
  Part 2: http://www.youtube.com/watch?v=hgZGtKWU-9g
  Part 3: http://www.youtube.com/watch?v=XilgPtj31co
  Part 4: http://www.youtube.com/watch?v=G4_tz97Ajhk
  Part 5: http://www.youtube.com/watch?v=5ZoeZ86o7VM

bystander wrote:Solstice Lunar Eclipse
http://asterisk.apod.com/vie ... 29&t=22335

Another time traveler, image taken prior to the event

hrmmmmm?

APOD Robot wrote:Pictured above is a digital prediction, in image form, for how the Moon and the surrounding sky could appear near maximum darkness.

(emphasis mine)

APOD Robot wrote:By coincidence this eclipse occurs on the day with the shortest amount of daylight in the northern hemisphere -- the Winter Solstice. This solstice eclipse is the first in 456 years, although so far it appears that no one has figured out when the next solstice eclipse will be.

December 21, 2094.

owlice wrote:hrmmmmm?

APOD Robot wrote:Pictured above is a digital prediction, in image form, for how the Moon and the surrounding sky could appear near maximum darkness.

(emphasis mine)

kill joy I saw that, just trying to have some fun.

http://www.astropix.com/HTML/SHOW_DIG/S ... clipse.HTM

Chris Peterson wrote:December 21, 2094.

2029 Dec 20 is pretty close.

http://eclipse.gsfc.nasa.gov/LEplot/LEp ... Dec20T.pdf

bystander wrote: kill joy

That's me; I aim to displease!

(Sorry about that!)

So now the APOD - in the final line of the caption - is claiming as well that this is a "solstice eclipse" and that this is something exceedingly rare ...

1) For 2/3 of the planet the eclipse and solstice happen on two subsequent calendar days, as they are some 15 hours apart. For example neither Hawaii nor (most of Europe) will see a 'solstice eclipse'. Just because they will in the mainland U.S. (or the UK, barely) doesn't make it a global truth.

2) Thanks to the 19-year Metonic cycle of repeating lunar phases the current pairing of a lunar eclipse and solstice within a 24-hour interval - granting a 'solstice eclipse' to certain longitudes - has also happened in December 1991 (when the lunar eclipse was partial) and will happen again in December 2029 (with a total eclipse, like now), so it isn't rare at all.

And 3) people got that all "figured out" long ago - in antiquity, actually ...

not shown or given in the image is perhaps a directional oritentation while looking at the other possible celestial objects, north-south-east-west. any advice?

Are you in Hawaii or the UK, Daniel? Why are you so bent out of shape? Nobody said it was any sort of 'global truth', that's your assumption. However, the webpage is written for a largely North American audience..... And it's sort of specified in the description, i.e.

wrote:"in the northern hemisphere"

And pointing put that there is another eclipse in Dec 2029 really doesn't mean anything, because for North American viewers, that one doesn't fall on the solstice.

Daniel Fischer wrote:So now the APOD - in the final line of the caption - is claiming as well that this is a "solstice eclipse" and that this is something exceedingly rare ...

1) For 2/3 of the planet the eclipse and solstice happen on two subsequent calendar days, as they are some 15 hours apart. For example neither Hawaii nor (most of Europe) will see a 'solstice eclipse'. Just because they will in the mainland U.S. (or the UK, barely) doesn't make it a global truth.

2) Thanks to the 19-year Metonic cycle of repeating lunar phases the current pairing of a lunar eclipse and solstice within a 24-hour interval - granting a 'solstice eclipse' to certain longitudes - has also happened in December 1991 (when the lunar eclipse was partial) and will happen again in December 2029 (with a total eclipse, like now), so it isn't rare at all.

And 3) people got that all "figured out" long ago - in antiquity, actually ...

For fellow Georgians that are interested… there is an eclipse viewing party at Tellus… link below:
http://www.tellusmuseum.org/events/luna ... e2010.html

river hills wrote:not shown or given in the image is perhaps a directional oritentation while looking at the other possible celestial objects, north-south-east-west. any advice?

river hills, maybe this map will help. It's mainly a map of the Orion area, which is visible in the APOD image just in the bottom edge. It may help orient you. (And I'm sure someone with better descriptive powers - - will be along shortly to further clarify.)

http://www.hawastsoc.org/deepsky/ori/orip.html


Happy lunar gazing!

Congratulations to Jerry for this APOD.
This is a true artistic photography that would require genuine photos.
Many greetings
César

Daniel Fischer wrote:1) For 2/3 of the planet the eclipse and solstice happen on two subsequent calendar days, as they are some 15 hours apart. For example neither Hawaii nor (most of Europe) will see a 'solstice eclipse'. Just because they will in the mainland U.S. (or the UK, barely) doesn't make it a global truth.

Irrelevant. We're talking about astronomical events here, and the only standardized way to specify when they happen is with Universal Time. This eclipse maximum is at UT 2010.12.21 08:17, and solstice is at UT 2010.12.21 23:38. The two instantaneous events occur on the same calendar date, and are separated by 15 hours, 21 minutes.

2) Thanks to the 19-year Metonic cycle of repeating lunar phases the current pairing of a lunar eclipse and solstice within a 24-hour interval - granting a 'solstice eclipse' to certain longitudes - has also happened in December 1991 (when the lunar eclipse was partial) and will happen again in December 2029 (with a total eclipse, like now), so it isn't rare at all.

Even that is arguably rare. But what is more rare, and is at issue here, is the two occurring on the same date.

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:

• 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

Furthermore I found the total lunar eclipse of 21 December 1638 (so 372 years instead of 456 years ago ago) to be a solstice total lunar eclipse:

• Year Mid totality Solstice Duration of totality
  
  1638 21.08 Dec. 21.67 Dec. 95 minutes

There are, of course, also partial and penumbral eclipses that coincide with the winter solstice. For instance:

• Year Mid totality Solstice Type
  
  2113 22.62 Dec. 21.99 Dec. partial
  2363 21.76 Dec. 22.66 Dec. penumbral
  2382 21.58 Dec. 22.28 Dec. partial

This list is not yet complete.

Carl Koppeschaar
http://www.astronet.nl

Daniel Fischer wrote:So now the APOD - in the final line of the caption - is claiming as well that this is a "solstice eclipse" and that this is something exceedingly rare ...

1) For 2/3 of the planet the eclipse and solstice happen on two subsequent calendar days, as they are some 15 hours apart. For example neither Hawaii nor (most of Europe) will see a 'solstice eclipse'. Just because they will in the mainland U.S. (or the UK, barely) doesn't make it a global truth.

2) Thanks to the 19-year Metonic cycle of repeating lunar phases the current pairing of a lunar eclipse and solstice within a 24-hour interval - granting a 'solstice eclipse' to certain longitudes - has also happened in December 1991 (when the lunar eclipse was partial) and will happen again in December 2029 (with a total eclipse, like now), so it isn't rare at all.

And 3) people got that all "figured out" long ago - in antiquity, actually ...

The 19-year Metonic cycle of repeating lunar phases only assures that a full moon will be happening again on December 21, 2029. A full moon is a necessary but not a sufficient condition for a lunar eclipse. A lunar eclipse requires a full moon that is located at one of the two precessing nodes of the orbit of the Moon on the plane of the ecliptic. It takes ~18.6 years for the nodes (which define both solar & lunar eclipses) to make one complete precession rotation; ergo, it would be impossible for the December 21, 2029 full moon (19 years hence) to be in eclipse as it will have passed by the nodal point five months prior.

The more relevant eclipse cycle (both solar & lunar) is the 18 years 11 1/3 days Saros cycle.
Ergo, there will probably be a lunar eclipse on January 1, 2029; however this won't be a solstice lunar eclipse.

http://en.wikipedia.org/wiki/Saros_cycle wrote:
<<The Saros cycle is an eclipse cycle with a period of 223 synodic months (approximately 6585.3213 days, or nearly 18 years 11 1/3 days), that can be used to predict eclipses of the Sun and Moon. One cycle after an eclipse, the Sun, Earth, and Moon return to approximately the same relative geometry, and a nearly identical eclipse will occur.>>

http://en.wikipedia.org/wiki/Lunar_precession wrote:
<<Precession of the nodes of the orbit of the Moon on the plane of the ecliptic (the plane of the lunar orbit is inclined to the ecliptic, and the points where they intersect- the nodes - precess) is caused by the flattening of the Earth; it is the period of the main nutation term in the orientation of the polar axis of the Earth. This nodal period is about 18.6 years, and the direction of motion is Westward. This is the reason that a draconic month (the period of time that the Moon takes to return to the same node) is shorter than the sidereal month. After one nodal precession period, the number of draconic months exceeds the number of sidereal months by exactly one. This period is about 6793 days (18.60 years). This nodal precession causes that the time for the Sun to return to the same node, the eclipse year, is about 18.623 days shorter than a sidereal year. The number of years of the nodal period equals the length of the year divided by this deficit, minus one.>>

Saying that "this eclipse occurs on the day with the shortest amount of daylight in the northern hemisphere - the Winter Solstice" clearly implies a statement correct for the whole globe and thus is simply wrong. Also APOD is read around the world and even translated, verbatim, into other languages, so all statements made there should either apply to the whole globe or be qualified precisely.

And while the Metonic cycle of course applies to the repetition of lunar phases, it also serves as a temporary eclipse repetition cycle for 4 or 5 cycles as can be found in http://en.wikipedia.org/wiki/Metonic_cy ... ical_basis - so there is a lunar eclipse on Dec. 20/21, 2029: http://www.eclipse.org.uk/eclipse/16120 ... 9Dec20.pdf ...

Daniel Fischer wrote:
Saying that "this eclipse occurs on the day with the shortest amount of daylight in the northern hemisphere - the Winter Solstice" clearly implies a statement correct for the whole globe and thus is simply wrong. Also APOD is read around the world and even translated, verbatim, into other languages, so all statements made there should either apply to the whole globe or be qualified precisely.

Saying that "this eclipse occurs on the day with the shortest amount of daylight in the northern hemisphere - the Winter Solstice" clearly implies a statement correct for the whole northern hemisphere and thus is true (whether or not the eclipse is visible in all parts of the northern hemisphere). Hawaii and all of Europe will see a 'solstice eclipse'.

Daniel Fischer wrote:
And while the Metonic cycle of course applies to the repetition of lunar phases, it also serves as a temporary eclipse repetition cycle for 4 or 5 cycles as can be found in http://en.wikipedia.org/wiki/Metonic_cy ... ical_basis - so there is a lunar eclipse on Dec. 20/21, 2029: http://www.eclipse.org.uk/eclipse/16120 ... 9Dec20.pdf ...

I'm not partial to partial lunar eclipses.

So in Mr Alfred E. Neumann's parallel Universe Europe and Hawaii - where the statement is wrong - don't belong to the Northern Hemisphere? And the clearly total - look at the diagram! - lunar eclipse of Dec. 2020 is partial? Very funny ...

Who's right about the last total eclipse on a solstice day : 372 years or 456 years?

This lunar eclipse falls on the date of the northern winter solstice. How rare is that? Total lunar eclipses in northern winter are fairly common. There have been three of them in the past ten years alone. A lunar eclipse smack-dab on the date of the solstice, however, is unusual. Geoff Chester of the US Naval Observatory inspected a list of eclipses going back 2000 years. "Since Year 1, I can only find one previous instance of an eclipse matching the same calendar date as the solstice, and that is 1638 DEC 21," says Chester. "Fortunately we won't have to wait 372 years for the next one...that will be on 2094 DEC 21."

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 ...

This is just fascinating. There was a total solar eclipse earlier this year. I didn't get to see it because it wasn't visible from my location, but my inability to see it did not negate the event.

So it is here. There IS a lunar eclipse on the solstice. That is a true statement around the world. That some people will be able to see and some not does not negate the statement.

"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. 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)!

Daniel Fischer wrote:
"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. 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)!

[c]The 2010 winter solstice will occur on December 21, at 23:38 pm UTC.
Totality will be reached earlier that day on December 21, at 08:17 am UTC.

It is not meaningless numerology, it is noteworthy that the eclipse will be so high in the northern sky.

NOVA Secrets of Stonehenge[/c]

Daniel Fischer wrote:"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.

Daniel Fischer wrote: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. I look forward to your reply.