Tag: Winter solstice

The Winter solstice

Today, we celebrate the shortest daylight! (In the Northern Hemisphere).

From WikiPedia:

The winter solstice, also called the hiemal solsticehibernal solstice, and brumal solstice, occurs when either of Earth‘s poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the winter solstice is the day with the shortest period of daylight and longest night of the year, when the Sun is at its lowest daily maximum elevation in the sky. Either pole experiences continuous darkness or twilight around its winter solstice. The opposite event is the summer solstice. Depending on the hemisphere’s winter solstice, at the Tropic of Cancer or Capricorn, the Sun reaches 90° below the observer’s horizon at solar midnight, to the nadir.

The winter solstice occurs during the hemisphere’s winter. In the Northern Hemisphere, this is the December solstice (usually December 21 or 22) and in the Southern Hemisphere, this is the June solstice (usually June 20 or 21). Although the winter solstice itself lasts only a moment, the term sometimes refers to the day on which it occurs. Other names are the “extreme of winter” (Dongzhi), or the “shortest day”. Since the 18th century, the term “midwinter” has sometimes been used synonymously with the winter solstice, although it carries other meanings as well. Traditionally, in many temperate regions, the winter solstice is seen as the middle of winter, but today in some countries and calendars, it is seen as the beginning of winter.

Since prehistory, the winter solstice has been seen as a significant time of year in many cultures, and has been marked by festivals and rituals. It marked the symbolic death and rebirth of the Sun. The seasonal significance of the winter solstice is in the reversal of the gradual lengthening of nights and shortening of days.

Sunrise at Stonehenge in southern England on the winter solstice

Later on, that article speaks of the Celtic history:

Celtic

Prior to the arrival of Christianity, the Celtic people of Britain celebrated Yule in a similar fashion to the Germanic festival. It is alleged that Celtic Druids began the tradition of the Yule Log, with the intention of driving out darkness, evil spirits, and poor luck in the following year. The Yule Log was intended to be kept alight over the entire solstice period, twelve days over which the sun was believed to stand still. The log being extinguished symbolised poor luck in the following year. Additionally, evergreen plants were used in decoration – of key significance are “The Holly and the Ivy”, used in decoration, and Mistletoe, suspended over a doorway in a token gesture of goodwill to all who passed under it. These traditions have been adopted into the Christian winter celebrations, symbolised by a mistletoe wreath placed on the front door to a building.

It is a most ancient celebration because as soon as humans recognised that this was the shortest day they were deeply respectful of the forces of the universe.

Mid-Winters Day.

An essay about the 2020 winter solstice!
Winter solstice 2020 in the Northern Hemisphere will be at 2:02 AM on Monday, December 21. That is our local Pacific Time which is 8 hours behind UTC.
So in UTC terms that is 10:02.
For some reason I have always regarded the Winter solstice as special, no doubt because in the Northern Hemisphere it is the time for the shortest day! It is the start of the new year!

Here is that essay published by The Conversation.

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What you need to know about this year’s winter solstice and the great conjunction

December 18, 2020
By William TeetsActing Director and Astronomer, Dyer Observatory, Vanderbilt University

Editor’s note: Dr. William Teets is the director of Vanderbilt University’s Dyer Observatory. In this interview, he explains what does and doesn’t happen during the winter solstice on Dec. 21. Another cosmic phenomenon is also going to occur on the same day called “the great conjunction,” where Saturn and Jupiter, both of which can be seen with the naked eye, will appear extremely close to one another.

What happens on the winter solstice?

The winter solstice this year happens on Dec. 21. This is when the Sun appears the lowest in the Northern Hemisphere sky and is at its farthest southern point over Earth – directly over the Tropic of Capricorn. For folks living at 23.5 degrees south latitude, not only does this day mark their summer solstice, but they also see the Sun directly over them at local noon. After that, the Sun will start to creep back north again.

The sequence of images below shows the path of the Sun through the sky at different times of the year. You can see how the Sun is highest in the Northern Hemisphere sky in June, lowest in December, and halfway in between these positions in March and September during the equinoxes.

The winter solstice is the shortest day in the Northern Hemisphere but not the day with the latest sunrise and earliest sunset. How is that possible?

The winter solstice doesn’t coincide with the latest sunrise or the earliest sunset. Those actually occur about two weeks before and two weeks after the winter solstice. This is because we are changing our distance from the sun due to our elliptical, not circular, orbit, which changes the speed at which we orbit.

If you were to look at where the Sun is at exactly the same time of day over different days of the year, you would see that it’s not always in the same spot. Yes, the Sun is higher in the summer and lower in the winter, but it also moves from side to side of the average noontime position, which also plays a role in when the Sun rises and sets.

One should also keep in mind that the seasons are due to the Earth’s axial tilt, not our distance from the Sun. Believe it or not, we are closest to the Sun in January.

What is ‘the great conjunction’?

Saturn and Jupiter have appeared fairly close together in our sky throughout the year. But on Dec. 21, Saturn and Jupiter will appear so close together that some folks may have a difficult time seeing them as two objects.

If you have a pair of binoculars, you’ll easily be able to spot both planets. In even a small telescope, you’d see both planets at the same time in the same field of view, which is really unheard of. That’s what makes this conjunction so rare. Jupiter and Saturn appear to meet up about every 20 years. Most of the time, however, they’re not nearly as close together as we’re going to see them on Monday, Dec. 21.

For a comparison, there was a great conjunction back in 2000, but the two planets were separated by about two full-Moon widths. This year, the orbits will bring them to where they appear to be about one-fifth of a full-Moon diameter.

We have been encouraging folks to go out and look at these planets using just their eyes between now and Dec. 21. You’ll actually be able to see how much they appear to move over the course of a single day.

The next time they will get this close together in our sky won’t be for another 60 years, so this is going to be a once-in-a-lifetime event for many people. In fact, the last time they got this close together was in the year 1623, but it was really difficult, if not impossible, to see them then because they appeared much closer to the Sun and set soon after it. Go back another 400 years to 1226 and this would have been the last time that we would have had a good view of this type of conjunction.

What advice would you give to people who want to see the great conjunction?

If weather permits at Dyer Observatory, we’ll be streaming a live view of the conjunction from one of the observatory’s telescopes, and I’ll be available to answer questions. Even if you don’t have a telescope or a pair of binoculars, definitely go out and check out this very rare alignment with your own eyes. Remember that they set soon after sunset, so be ready to view right at dusk!

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From the introduction that was received by email:

I want to include another piece on the conjunction. It comes from the introduction to that item above: It’s been a tough year. To many of us, every day during the coronavirus pandemic has felt incredibly long. Perhaps it will come as a relief that Monday will be the shortest day of the year. December 21 will also bring a rare cosmic phenomenon. If the sky is clear over the next few nights, look out just over the southwest horizon. You may see Jupiter and Saturn coming together and then drifting apart in an event known as “the great conjunction.” Although this occurs once every two decades, the last time they came this close, and we Earthlings got such a clear view, was in 1226.

I also want to include a copy of an article on the website belonging to KRCC  that talks of the Great Conjunction.

Why The Jupiter And Saturn Conjunction During The 2020 Winter Solstice Is Extra Special

By Mike Procell

December 18, 2020

The conjunction of Jupiter and Saturn appears over Cheyenne Mountain in Colorado Springs. Jupiter appears brighter and to the lower right of Saturn. Saturn, to Jupiter’s upper left, has a slightly golden hue. Photo taken December 5, 2020. The planets will be closer than they have been observed from earth in over 800 years on the Winter Solstice

A rare celestial event will help mark the Winter Solstice in the northern hemisphere on Monday, Dec. 21.

Jupiter and Saturn are currently appearing very close together from an earthly vantage point. These two gas giants are in conjunction, an occurrence that happens every 20 years or so.

This one though, is extra special.

“Really, really close conjunctions like this one are quite rare,” said Hal Bidlack with the Colorado Springs Astronomical Society. “We haven’t been able to observe Jupiter and Saturn this close since the year 1226. And we won’t see them again this close for decades and decades to come.”

The two planets were last about this close together in the year 1623. But the pairing occurred while the planets were close to the sun from earth’s perspective, Bidlack said, and the sight was basically washed out in the sun’s glare.
In reality, Saturn and Jupiter are hundreds of millions of miles apart.

“On the 21st they will appear so close that if you held a dime on edge at arm’s length, that’s how close they would be together,” Bidlack said.

From Colorado Springs, sky gazers only need to look toward Cheyenne Mountain to catch a glimpse. Elsewhere in Colorado, Bidlack said folks can look to the southwestern skies, low near the horizon.

The pair sets around an hour and a half after the sun does, about 4:39 p.m. on Monday.

The planets will begin to separate when viewed from Earth, and will eventually disappear altogether from the night sky until reappearing in the morning sky in early 2021. See more skywatching tips from NASA.

If you have managed to stay on today’s post until near the end you would have seen the following: “We haven’t been able to observe Jupiter and Saturn this close since the year 1226. And we won’t see them again this close for decades and decades to come.”

Just about 800 years ago since this last happened.

If you can, go outside with a telescope or a pair of binoculars and watch the sight! That time of the sunset is 4:39 PM Pacific Time. I think that wherever you are in the world starting to watch as soon as  it is dark would be a good idea.

For me the new year starts now!

Happy Solstice!

That Winter Solstice

Good people, this is mid-Winter.

(Northern Hemisphere only.)

OK, not in the sense of weather because the worse is yet to come I’m sure. But in terms of the movement of the Planet Earth in its orbit around the Sun. And that’s what matters!

This is a really ancient moment as the following article published in The Conversation explains in much more detail.

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What winter solstice rituals tell us about indigenous people

By    Associate Professor of Environmental Studies, The University of Montana

December 13th, 2018.

On the day of winter solstice, many Native American communities will hold religious ceremonies or community events.

The winter solstice is the day of the year when the Northern Hemisphere has the fewest hours of sunlight and the Southern Hemisphere has the most. For indigenous peoples, it has been a time to honor their ancient sun deity. They passed their knowledge down to successive generations through complex stories and ritual practices.

As a scholar of the environmental and Native American religion, I believe, there is much to learn from ancient religious practices.

Ancient architecture

For decades, scholars have studied the astronomical observations that ancient indigenous people made and sought to understand their meaning.

One such place was at Cahokia, near the Mississippi River in what is now Illinois across from St. Louis.

The Cahokia mounds. Doug Kerr, CC BY-SA

In Cahokia, indigenous people built numerous temple pyramids or mounds, similar to the structures built by the Aztecs in Mexico, over a thousand years ago. Among their constructions, what most stands out is an intriguing structure made up of wooden posts arranged in a circle, known today as “Woodhenge.”

To understand the purpose of Woodhenge, scientists watched the sun rise from this structure on winter solstice. What they found was telling: The sun aligned with both Woodhenge and the top of a temple mound – a temple built on top of a pyramid with a flat top – in the distance. They also found that the sun aligns with a different temple mound on summer solstice.

Archaeological evidence suggests that the people of Cahokia venerated the sun as a deity. Scholars believe that ancient indigenous societies observed the solar system carefully and wove that knowledge into their architecture.

Scientists have speculated that the Cahokia held rituals to honor the sun as a giver of life and for the new agricultural year.

Complex understandings

Zuni Pueblo is a contemporary example of indigenous people with an agricultural society in western New Mexico. They grow corn, beans, squash, sunflowers and more. Each year they hold annual harvest festivals and numerous religious ceremonies, including at the winter solstice.

At the time of the winter solstice they hold a multiday celebration, known as the Shalako festival. The days for the celebration are selected by the religious leaders. The Zuni are intensely private, and most events are not for public viewing.

But what is shared with the public is near the end of the ceremony, when six Zuni men dress up and embody the spirit of giant bird deities. These men carry the Zuni prayers for rain “to all the corners of the earth.” The Zuni deities are believed to provide “blessings” and “balance” for the coming seasons and agricultural year.

As religion scholar Tisa Wenger writes, “The Zuni believe their ceremonies are necessary not just for the well-being of the tribe but for “the entire world.”

Winter games

Not all indigenous peoples ritualized the winter solstice with a ceremony. But that doesn’t mean they didn’t find other ways to celebrate.

The Blackfeet tribe in Montana, where I am a member, historically kept a calendar of astronomical events. They marked the time of the winter solstice and the “return” of the sun or “Naatosi” on its annual journey. They also faced their tipis – or portable conical tents – east toward the rising sun.

They rarely held large religious gatherings in the winter. Instead the Blackfeet viewed the time of the winter solstice as a time for games and community dances. As a child, my grandmother enjoyed attending community dances at the time of the winter solstice. She remembered that each community held their own gatherings, with unique drumming, singing and dance styles.

Later, in my own research, I learned that the Blackfeet moved their dances and ceremonies during the early reservation years from times on their religious calendar to times acceptable to the U.S. government. The dances held at the time of the solstice were moved to Christmas Day or to New Year’s Eve.

The solstice. Divad, from Wikimedia Commons

Today, my family still spends the darkest days of winter playing card games and attending the local community dances, much like my grandmother did.

Although some winter solstice traditions have changed over time, they are still a reminder of indigenous peoples understanding of the intricate workings of the solar system. Or as the Zuni Pueblo’s rituals for all peoples of the earth demonstrate – of an ancient understanding of the interconnectedness of the world.

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Let me pick up on the last sentence: “Or as the Zuni Pueblo’s rituals for all peoples of the earth demonstrate – of an ancient understanding of the interconnectedness of the world.”

We are all of us interconnected across the world. We have been for a very long time.

The importance of understanding this, truly understanding this, is critical to our future.

Our Winter Solstice.

Is the moment of publishing this post.

I thought it would make a nice change to publish tomorrow’s post a little earlier than usual. To be precise to publish it on Dec. 22, at 04:48, Coordinated Universal Time (UTC). Or in our local Pacific Standard Time (PST) UTC-8 hrs or 20:48 Dec. 21., i.e. 20:48 on the evening of the 21st December. (I am seeing the exact time being declared as 04:48 or 04:49 UTC depending on what you read.)

Granted that the Northern Hemisphere tends to deliver the worst of the Winter weather after the shortest day, it still is good to know that for the next six months, the hours of daylight, in the Northern Hemisphere, will be increasing.

My inclination to write a post on the topic was greatly influenced by a most beautiful post over on Val Boyco’s blogsite. It was called And Winter Came.  Here’s the video that Val included in her post.

Isn’t that a most beautiful few minutes!

Impossible to top that!

But I can continue including an informative item that was published over on Mother Nature News, and is republished here within the terms of MNN.

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8 things to know about the winter solstice

From when it happens to why, here’s your crash course on the shortest day of the year.

By: Melissa Breyer, December 18, 2015

Hello, winter. (Photo: psynovec/Shutterstock)
Hello, winter. (Photo: psynovec/Shutterstock)

“A day without sunshine is like, you know, night,” quipped Steve Martin – and indeed, even a day with less sunshine can feel a bit dark. Our world depends on the light radiating from that big star we traipse around, and when it’s in short supply, we feel it. But if you count yourself amongst those who don’t love waking up before the sun rises and getting off work after it has set, things are about to lighten up. Hello, winter solstice!

Although winter is really just beginning, we can at least say goodbye to these short little days we’ve been suffering (and don’t let the door hit you on the way out). With that in mind, here’s a collection of curious facts to celebrate the long-awaited return to longer days.

1. There are actually two winter solstices every year


It’s sometimes easy to be hemisphere-o-centric, but the other side of the planet gets a winter solstice too. With the planet’s orbit tilted on its axis, Earth’s hemispheres swap who gets direct sun over the course of a year. Even though the Northern Hemisphere is closer to the sun during the winter, it’s the tilt away from the sun that causes cold temperatures and less light — which is when the Southern Hemisphere is toasty. So while our winter solstice is on Dec. 21 or 22, the Southern Hemisphere celebrates the same on June 21 or 22.

Here’s how that looks from space (kind of):

2. The winter solstice happens in the blink of an eye


Although the solstice is marked by a whole day on the calendar, it’s actually just the brief moment when the sun is exactly over the Tropic of Capricorn that the event occurs.

3. Which is why it happens on different days in the same year

What? Yes! In 2015, the solstice happens on Dec. 22, at 04:49 on the Coordinated Universal Time (UTC) time clock, the time standard that the world regulates its hours by. Which means any location that is at least five hours behind UTC should break out the party hats on Dec. 21. For example, in the United States the winter solstice happens on Dec. 21 at 11:49 p.m. Eastern Standard Time. The rest of the time zones can welcome longer days beginning on the 22nd.

4. It’s the first day of winter … or it’s not, depending on whom you ask

Meteorologists consider the first day of winter to be Dec. 1, but ask an astronomer — or just about anyone else — and they’ll likely answer that the winter solstice marks the start of the season. There are two ways to look at it: meteorological seasons and astronomical seasons. Meteorological seasons are based on the annual temperature cycle, explains NOAA, while astronomical seasons are based on the position of the Earth in relation to the sun.

5. It’s a time of gloriously long shadows

Shadows are at their playful best on the solstice. (Photo: Mike Page/flickr)
Shadows are at their playful best on the solstice. (Photo: Mike Page/flickr)

If you’re inclined to take pleasure in the little things, like shadows that seem cast from a funhouse mirror, then the winter solstice is the time for you. It’s now that the sun is at its lowest arc across the sky and thus, shadows from its light are at their longest. (Imagine a flashlight directly above your head and one hitting you from the side, and picture the respective shadows.) And in fact, your noontime shadow on the solstice is the longest it will be all year. Relish those long legs while you can.

6. Full solstice moons are rarer than blue ones

Since 1793, the full moon has only occurred on the winter solstice 10 times, according to the Farmer’s Almanac. The last one was in 2010, which was also a lunar eclipse! The next full moon on a winter solstice won’t be until 2094.

7. There’s a Christmas connection

Since Christ wasn’t issued a birth certificate, there’s no record of the date when he was supposed to have been born. Meanwhile, humans have been celebrating the winter solstice throughout history — the Romans had their feast of Saturnalia, early German and Nordic pagans had their yuletide celebrations. Even Stonehenge has connections to the solstice. But eventually Christian leaders, endeavoring to attract pagans to their faith, added Christian meaning to these traditional festivals. Many Christmas customs, like the Christmas tree, can be directly traced to solstice celebrations.

8. It’s a reminder to thank Copernicus

Will the real Saint Nick please step forward? (Photo: Wikimedia Commons)
Will the real Saint Nick please step forward? (Photo: Wikimedia Commons)

The word “solstice” comes from the Latin solstitium, meaning “point at which the sun stands still.” Since when has the sun ever moved?! Of course, before Renaissance astronomer Nicolaus Copernicus (aka “super smartypants”) came up with the ‘ol heliocentric model, we all figured that everything revolved around the Earth, sun included. Our continued use of the word “solstice” is a beautiful reminder of just how far we’ve come and provides a nice opportunity to give a tip of the hat to great thinkers who challenged the status quo.

And now go have some hot cocoa. Happy winter!

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Only one way to close. That is with this picture of the sun perfectly aligned with the stones at Stonehenge in Wiltshire, UK at the moment of the Winter Solstice.

The December solstice happens at the same instant for all of us, everywhere on Earth. This year the solstice occurs on Tuesday December 22nd at 04:49 GMT (Universal time) with the sun rising over Stonehenge in Wiltshire at 08:04.
The December solstice happens at the same instant for all of us, everywhere on Earth. This year the solstice occurs on Tuesday December 22nd at 04:49 GMT (Universal time) with the sun rising over Stonehenge in Wiltshire at 08:04.

Stay safe and warm wherever you are.

The next post from Learning from Dogs will be published at 00:00 PST Wednesday, 23rd December.

Ancient rhythms.

The Winter Solstice.

I’m breaking the pattern of publishing a new post at midnight, Pacific Time, (08:00 UTC) because it seemed like fun to publish Monday’s post at the moment of the Winter Solstice; namely Sunday, December 21 at 23:03 UTC (15:03 PST).

There is no doubt in my mind that everyone is familiar with the Winter Solstice being the moment when the planet has perfect opposites, in terms of light and darkness, as the following image shows so clearly.

Day and night sides of Earth at the instant of the December 2014 solstice (2014 December 21 at 23:03 Universal Time). Note that the north polar region of Earth must endure 24 hours of night, while the south polar region gets to bask in 24 hours of daylight. Image credit: Earth and Moon Viewer
Day and night sides of Earth at the instant of the December 2014 solstice (2014 December 21 at 23:03 Universal Time). Note that the north polar region of Earth must endure 24 hours of night, while the south polar region gets to bask in 24 hours of daylight. Image credit: Earth and Moon Viewer

What may not be so well-known is that it occurs within about two-and-a-half hours of the new moon.

From times immemorial, early peoples on Earth knew much about the sun and the seasons, the length of daylight, and how the direction of the sunrise and sunset all shifted in a regular way throughout the year. As an Englishman, who in past times frequently drove the A303 road between London and Exeter, going past the ancient site of Stonehenge was always wonderful. Many are familiar with the sun rising during the Summer Solstice over the Heel Stone but far fewer realise that Stonehenge also marks the sun’s dawning the morning after the Winter Solstice.

winter-solstice-stonehenge
The shortest day is behind us.

 

The English Heritage website Discover Stonehenge is brim full of facts and information so won’t ‘copy and paste’ from one to the other! Suffice to say that what we see today was completed about 3500 years ago.

However, it seems as though the ancient site is still delivering new surprises.  I write this simply because just a few days ago, on the 19th December, 2014, the BBC reported:

Stonehenge dig finds 6,000-year-old encampment

Archaeologists found the encampment during a dig at Blick Mead near Stonehenge
Archaeologists found the encampment during a dig at Blick Mead near Stonehenge

Archaeologists working on a site near Stonehenge say they have found an untouched 6,000-year-old encampment which “could rewrite British history”.

David Jacques, from the University of Buckingham, made the discovery at Blick Mead in October, and said the carbon dating results had just been confirmed.

But he also raised concerns about possible damage to the site over plans to build a road tunnel past Stonehenge.

The Department of Transport said it would “consult before any building”.

The Blick Mead site is about 1.5 miles (2.4km) from Stonehenge and archaeologists said “scientifically tested charcoal” dug up from the site had “revealed that it dated from around 4000 BC”.

The archaeologists found burnt flints, remains of animals and tools
The archaeologists found burnt flints, remains of animals and tools

David Jacques said the dig had also found “evidence of feasting” including burnt flints, tools and remains of giant cattle, known as aurochs, which were eaten by early hunter gatherers.

Mr Jacques said: “British pre-history may have to be rewritten. This is the latest dated Mesolithic encampment ever found in the UK.

“Blick Mead site connects the early hunter gatherer groups returning to Britain after the Ice Age to the Stonehenge area, all the way through to the Neolithic in the late 5th Millennium BC.

“But our only chance to find out about the earliest chapter of Britain’s history could be wrecked if the tunnel goes ahead.”

Archaeologists said the latest carbon date suggested it was continuously occupied between 7500-4000 BC
Archaeologists said the latest carbon date suggested it was continuously occupied between 7500-4000 BC

Andy Rhind-Tutt, a former mayor and current chairman of Amesbury Museum, which part-funded the dig, said the discovery could “provide what archaeologists have been searching for centuries – the answer to the story of the pre-history of Stonehenge.”

Earlier this month, the government announced funding for a 1.8-mile (2.9km) tunnel to remove congestion from the main road past Stonehenge.

A Department for Transport spokesman said: “As with any road scheme, we will consult with interested parties before any building begins on the A303.

“English Heritage and National Trust are supportive of our plans, and we will ensure sites of cultural or historical significance are safeguarded as we progress with the upgrade.”

The A303 past Stonehenge is a highly congested route.
The A303 past Stonehenge is a highly congested route.

So as the planet and the sun continue their dance to a rhythm, ancient beyond comprehension, let us reflect on the scale of the universe and our fortune to be alive this Winter Solstice, 2014.

That beautiful lunar eclipse

As it happens, here in Payson at 01:15 am on the morning of Tuesday, 21st December, low broken cloud was obscuring the moon much of the time.  But nonetheless the pale outline of the darkened moon was visible, sitting above the constellation of Orion.  Very, very mystical.

Here’s what it looked like without the cloud, thanks to a Google search for images.

Dec 21st 1638; Dec 21st 2010; Dec 21st 2094

And a late update, thanks to Pete N (via Facebook) who spotted this wonderful video recently placed on YouTube.

which then highlighted this video taken by the Kurdistan Planetarium – these are amazing examples of the power of our new virtual world in sharing images across so many peoples.

Solstice Lunar Eclipse

(Again, thanks to Dan G for highlighting this.)

If you want to see this solar eclipse then read the times carefully – to assist, I am publishing this Post much earlier than normal, at 18:00 US Mountain Time (UTC -7hrs) on Monday, 20th December.  Oh, and more information at Spacedex here.

SOLSTICE LUNAR ECLIPSE
by Dr. Tony Phillips
Reprinted from http://science.nasa.gov ( but this link address is better. Ed.)

Dec. 17, 2010:  Everyone knows that “the moon on the breast of new-fallen snow gives the luster of mid-day to objects below.”

That is, except during a lunar eclipse.

The luster will be a bit “off” on Dec. 21st, the first day of northern winter, when the full Moon passes almost dead-center through

A similar lunar eclipse in Nov. 2003. Credit: Jim Fakatselis.

Earth’s shadow. For 72 minutes of eerie totality, an amber light will play across the snows of North America, throwing landscapes into an unusual state of ruddy shadow.

The eclipse begins on Tuesday morning, Dec. 21st, at 1:33 am EST (Monday, Dec. 20th, at 10:33 pm PST). At that time, Earth’s shadow will appear as a dark-red bite at the edge of the lunar disk. It takes about an hour for the “bite” to expand and swallow the entire Moon. Totality commences at 02:41 am EST (11:41 pm PST) and lasts for 72 minutes.

If you’re planning to dash out for only one quick look — it is December, after all — choose this moment: 03:17 am EST (17 minutes past midnight PST). That’s when the Moon will be in deepest shadow, displaying the most fantastic shades of coppery red.

Credit: F. Espenak, NASA/GSFC.

From first to last bite, the eclipse favors observers in North America. The entire event can be seen from all points on the continent. Click to view a world map of visibility circumstances. Credit: F. Espenak, NASA/GSFC.

Why red?

A quick trip to the Moon provides the answer: Imagine yourself standing on a dusty lunar plain looking up at the sky. Overhead hangs Earth, nightside down, completely hiding the sun behind it. The eclipse is underway. You might expect Earth seen in this way to be utterly dark, but it’s not. The rim of the planet is on fire! As you scan your eye around Earth’s circumference, you’re seeing every sunrise and every sunset in the world, all of them, all at once. This incredible light beams into the heart of Earth’s shadow, filling it with a coppery glow and transforming the Moon into a great red orb.

Back on Earth, the shadowed Moon paints newly fallen snow with unfamiliar colors–not much luster, but lots of beauty.

Enjoy the show.

Coincidences (UPDATED): 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.