Remains of Earth’s oldest forest found in New York

Scientists have discovered what’s now Earth’s oldest known forest, at a sandstone quarry near Cairo, New York. They found three types of ancient trees, with what they called “surprisingly modern root systems,” dating back to 386 million years ago. Analysis of these trees suggests our world’s transition toward forests as we know them today began several million years earlier than formerly believed. The findings – published in the December 19, 2019, issue of the journal Current Biology – shed new light on the early evolution of the trees that help shape and reshape our planet’s surface, oceans and air.

The team consisted of scientists at Binghamton University, New York State Museum and Cardiff University. These researchers mapped over 3,000 square meters (around 3/4 of an acre) of the forest at an abandoned quarry in the foothills of the Catskill Mountains, at the northeastern end of the Allegheny Plateau. A statement from Binghamton University explained:

While sifting through fossil soils in the Catskill region … researchers uncovered the extensive root system of 385-million-year old trees that existed during the Devonian Period. While seed plants didn’t appear until some 10 million years later, these preserved root systems show evidence of the presence of trees with leaves and wood – both of which are common in modern seed plants.

Lead author William Stein, emeritus professor of biological sciences at Binghamton University, said:

The Devonian Period represents a time in which the first forest appeared on planet Earth. The effects were of first order magnitude in terms of changes in ecosystems, what happens on the Earth’s surface and oceans, CO2 concentration in the atmosphere and global climate.

So many dramatic changes occurred at that time as a result of those original forests that, basically, the world has never been the same since.

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Large bare flat area with a row of big rocks and branching lines etched onto the ground.

Some of the fossilized roots uncovered at the quarry near Cairo, New York. Via Cardiff University.

Before this new discovery, in 2012, Stein and his team had conducted research at the fossil forest at Gilboa in New York State, often described as Earth’s oldest known forest. Their statement explained:

The discovery at Cairo, about a 40-minute drive from the original site, now reveals an even older forest with dramatically different composition.

The Cairo forest is around 2 or 3 million years older than that at Gilboa. The research team commented in a statement from Cardiff University that the Cairo forest is older than the one at Gilboa because the fossils were lower down in the sequence of rocks that occur in the Catskill mountains.

The scientists explained:

The Cairo site presents three unique root systems, leading Stein and his team to hypothesize that much like today, the forests of the Devonian Period were heterogeneous with different trees occupying different places depending on local conditions.

First, Stein and his team identified a rooting system that they believe belonged to a palm tree-like tree called Eospermatopteris. This plant, first identified at the Gilboa site, had relatively rudimentary roots. Like a weed, Eospermatopteris likely occupied many environments, explaining its presence at both sites. But its roots had relatively limited range and probably lived only a year or two before dying and being replaced by other roots that would occupy the same space.

The researchers also found evidence of a tree called Archaeopteris, which shares a number of characteristics with modern seed plants. Although this tree behaved more like a fern during reproduction, by releasing spores into the air instead of forming seeds, it had early hints at what would one day become seed plants: Archaeopteris is the first known plant to form leaves, and was a large woody plant formed from secondary tissues. At Cairo, this tree was now found to also have a strikingly modern underground system allowing for continuous expansion of roots accommodating continuous growth of a long-lived larger type of tree, and potentially dominating the local forest ecosystem.

Man with a push-broom sweeping a flat natural surface, yellow front end loader in background.

Cleaning the surface at the Cairo fossil forest site. Image via William Stein/ Binghamton University.

Stein commented:

Archaeopteris seems to reveal the beginning of the future of what forests will ultimately become. Based on what we know from the body fossil evidence of Archaeopteris prior to this, and now from the rooting evidence that we’ve added at Cairo, these plants are very modern compared to other Devonian plants. Although still dramatically different than modern trees, Archaeopteris nevertheless seems to point the way toward the future of forests.

Stein and his team were also surprised to find a third root system in the fossilized soil at Cairo, belonging to a tree thought to only exist during the Carboniferous Period and beyond: “scale trees” belonging to the class Lycopsida. Stein explained:

What we have at Cairo is a rooting structure that appears identical to great trees of the Carboniferous coal swamps with fascinating elongated roots. But no one has yet found body fossil evidence of this group this early in the Devonian. Our findings are perhaps suggestive that these plants were already in the forest, but perhaps in a different environment and earlier than generally believed. Yet we only have a footprint, and we await additional fossil evidence for confirmation.

Co-author of the study Chris Berry of Cardiff University commented:

It is surprising to see plants which were previously thought to have had mutually exclusive habitat preferences growing together on the ancient Catskill delta.

These researchers believe the forest was eventually wiped out by a flood, due to the presence of many fish fossils that were also visible on the surface of the quarry.

Radiating uneven light-colored lines on large ray, flat, bare natural surface.

Archaeopteris root system at the Cairo fossil forest site at first discovery. Image via Charles Ver Straeten/ Binghamton University.

Bottom line: The oldest known forest, dating to 386 million years ago, was uncovered by scientists at a quarry near Cairo, New York. Their discovery provides new insights into the early evolution of trees that helped reshape our planet and was published in the December 19, 2019, issue of the journal Current Biology.

Source: Mid-Devonian Archaeopteris Roots signal Revolutionary Change in Earliest Fossil Forest

Via Binghamton University

Via Cardiff University



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Scientists have discovered what’s now Earth’s oldest known forest, at a sandstone quarry near Cairo, New York. They found three types of ancient trees, with what they called “surprisingly modern root systems,” dating back to 386 million years ago. Analysis of these trees suggests our world’s transition toward forests as we know them today began several million years earlier than formerly believed. The findings – published in the December 19, 2019, issue of the journal Current Biology – shed new light on the early evolution of the trees that help shape and reshape our planet’s surface, oceans and air.

The team consisted of scientists at Binghamton University, New York State Museum and Cardiff University. These researchers mapped over 3,000 square meters (around 3/4 of an acre) of the forest at an abandoned quarry in the foothills of the Catskill Mountains, at the northeastern end of the Allegheny Plateau. A statement from Binghamton University explained:

While sifting through fossil soils in the Catskill region … researchers uncovered the extensive root system of 385-million-year old trees that existed during the Devonian Period. While seed plants didn’t appear until some 10 million years later, these preserved root systems show evidence of the presence of trees with leaves and wood – both of which are common in modern seed plants.

Lead author William Stein, emeritus professor of biological sciences at Binghamton University, said:

The Devonian Period represents a time in which the first forest appeared on planet Earth. The effects were of first order magnitude in terms of changes in ecosystems, what happens on the Earth’s surface and oceans, CO2 concentration in the atmosphere and global climate.

So many dramatic changes occurred at that time as a result of those original forests that, basically, the world has never been the same since.

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Large bare flat area with a row of big rocks and branching lines etched onto the ground.

Some of the fossilized roots uncovered at the quarry near Cairo, New York. Via Cardiff University.

Before this new discovery, in 2012, Stein and his team had conducted research at the fossil forest at Gilboa in New York State, often described as Earth’s oldest known forest. Their statement explained:

The discovery at Cairo, about a 40-minute drive from the original site, now reveals an even older forest with dramatically different composition.

The Cairo forest is around 2 or 3 million years older than that at Gilboa. The research team commented in a statement from Cardiff University that the Cairo forest is older than the one at Gilboa because the fossils were lower down in the sequence of rocks that occur in the Catskill mountains.

The scientists explained:

The Cairo site presents three unique root systems, leading Stein and his team to hypothesize that much like today, the forests of the Devonian Period were heterogeneous with different trees occupying different places depending on local conditions.

First, Stein and his team identified a rooting system that they believe belonged to a palm tree-like tree called Eospermatopteris. This plant, first identified at the Gilboa site, had relatively rudimentary roots. Like a weed, Eospermatopteris likely occupied many environments, explaining its presence at both sites. But its roots had relatively limited range and probably lived only a year or two before dying and being replaced by other roots that would occupy the same space.

The researchers also found evidence of a tree called Archaeopteris, which shares a number of characteristics with modern seed plants. Although this tree behaved more like a fern during reproduction, by releasing spores into the air instead of forming seeds, it had early hints at what would one day become seed plants: Archaeopteris is the first known plant to form leaves, and was a large woody plant formed from secondary tissues. At Cairo, this tree was now found to also have a strikingly modern underground system allowing for continuous expansion of roots accommodating continuous growth of a long-lived larger type of tree, and potentially dominating the local forest ecosystem.

Man with a push-broom sweeping a flat natural surface, yellow front end loader in background.

Cleaning the surface at the Cairo fossil forest site. Image via William Stein/ Binghamton University.

Stein commented:

Archaeopteris seems to reveal the beginning of the future of what forests will ultimately become. Based on what we know from the body fossil evidence of Archaeopteris prior to this, and now from the rooting evidence that we’ve added at Cairo, these plants are very modern compared to other Devonian plants. Although still dramatically different than modern trees, Archaeopteris nevertheless seems to point the way toward the future of forests.

Stein and his team were also surprised to find a third root system in the fossilized soil at Cairo, belonging to a tree thought to only exist during the Carboniferous Period and beyond: “scale trees” belonging to the class Lycopsida. Stein explained:

What we have at Cairo is a rooting structure that appears identical to great trees of the Carboniferous coal swamps with fascinating elongated roots. But no one has yet found body fossil evidence of this group this early in the Devonian. Our findings are perhaps suggestive that these plants were already in the forest, but perhaps in a different environment and earlier than generally believed. Yet we only have a footprint, and we await additional fossil evidence for confirmation.

Co-author of the study Chris Berry of Cardiff University commented:

It is surprising to see plants which were previously thought to have had mutually exclusive habitat preferences growing together on the ancient Catskill delta.

These researchers believe the forest was eventually wiped out by a flood, due to the presence of many fish fossils that were also visible on the surface of the quarry.

Radiating uneven light-colored lines on large ray, flat, bare natural surface.

Archaeopteris root system at the Cairo fossil forest site at first discovery. Image via Charles Ver Straeten/ Binghamton University.

Bottom line: The oldest known forest, dating to 386 million years ago, was uncovered by scientists at a quarry near Cairo, New York. Their discovery provides new insights into the early evolution of trees that helped reshape our planet and was published in the December 19, 2019, issue of the journal Current Biology.

Source: Mid-Devonian Archaeopteris Roots signal Revolutionary Change in Earliest Fossil Forest

Via Binghamton University

Via Cardiff University



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December solstice starts shortest season

The December solstice will come on December 22, 2019, at 4:19 UTC. That’s 10:19 p.m. (22:19) CST on December 21 for those in the central time zone in North America. It’s when the sun reaches its southernmost point for the year. This solstice marks the beginning of the winter season in the Northern Hemisphere, and the start of the summer season in the Southern Hemisphere. And, no matter where you are on Earth, it marks the beginning of your shortest season.

By season, we mean the time between a solstice and an equinox, or vice versa. The upcoming season – between the December solstice and March equinox – is a touch shy of 89 days.

Contrast the number of days of the upcoming season with that of the longest season, a Northern Hemisphere summer or Southern Hemisphere winter. The longest season as measured from the June solstice to the September equinox lasts 93.65 days.

Why is the upcoming season nearly five days shorter? Keep reading to learn more.

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View of moon and Mars in east before dawn.

Are you a morning person.? Then watch for the moon to go by the celestial line-up: Spica, the brightest star in the constellation Virgo, Zubenelgenubi, the constellation Libra’s alpha star, and Mars, the 4th planet from the sun.

Here’s why the seasons are different lengths. Every year in early January, the Earth swings closest to the sun for the year. Because Earth is nearest the sun at this time, Earth moves most swiftly in its orbit. That’s why a Northern Hemisphere winter or Southern Hemisphere summer is the shortest of the four seasons.

On the other hand, in early July, Earth is farthest from the sun and moving most slowly in its orbit.

Lengths of the astronomical seasons:

December solstice to March equinox: 88.99 days
March equinox to June solstice: 92.76 days
June solstice to September equinox: 93.65 days
September equinox to December solstice: 89.84 days

According to the computational wizard Jean Meeus, a Northern Hemisphere winter or Southern Hemisphere summer became the shortest season after the year 1246. The astronomical season between the December solstice and the March equinox will reach a minimum value of 88.71 days around the year 3500, and will continue to reign as the shortest season until about 6430.

Bottom line: By season, we mean the time between a solstice and an equinox, or vice versa. Shortest season begins on December 22, 2019. It’s a touch shy of 89 days in length.

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The December solstice will come on December 22, 2019, at 4:19 UTC. That’s 10:19 p.m. (22:19) CST on December 21 for those in the central time zone in North America. It’s when the sun reaches its southernmost point for the year. This solstice marks the beginning of the winter season in the Northern Hemisphere, and the start of the summer season in the Southern Hemisphere. And, no matter where you are on Earth, it marks the beginning of your shortest season.

By season, we mean the time between a solstice and an equinox, or vice versa. The upcoming season – between the December solstice and March equinox – is a touch shy of 89 days.

Contrast the number of days of the upcoming season with that of the longest season, a Northern Hemisphere summer or Southern Hemisphere winter. The longest season as measured from the June solstice to the September equinox lasts 93.65 days.

Why is the upcoming season nearly five days shorter? Keep reading to learn more.

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View of moon and Mars in east before dawn.

Are you a morning person.? Then watch for the moon to go by the celestial line-up: Spica, the brightest star in the constellation Virgo, Zubenelgenubi, the constellation Libra’s alpha star, and Mars, the 4th planet from the sun.

Here’s why the seasons are different lengths. Every year in early January, the Earth swings closest to the sun for the year. Because Earth is nearest the sun at this time, Earth moves most swiftly in its orbit. That’s why a Northern Hemisphere winter or Southern Hemisphere summer is the shortest of the four seasons.

On the other hand, in early July, Earth is farthest from the sun and moving most slowly in its orbit.

Lengths of the astronomical seasons:

December solstice to March equinox: 88.99 days
March equinox to June solstice: 92.76 days
June solstice to September equinox: 93.65 days
September equinox to December solstice: 89.84 days

According to the computational wizard Jean Meeus, a Northern Hemisphere winter or Southern Hemisphere summer became the shortest season after the year 1246. The astronomical season between the December solstice and the March equinox will reach a minimum value of 88.71 days around the year 3500, and will continue to reign as the shortest season until about 6430.

Bottom line: By season, we mean the time between a solstice and an equinox, or vice versa. Shortest season begins on December 22, 2019. It’s a touch shy of 89 days in length.

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Scientists see a new kind of explosion on the sun

NASA’s Solar Dynamics Observatory (SDO) has observed a kind of magnetic explosion on the sun that scientists have never seen before. The spacecraft spied the explosion in the scorching upper reaches of the sun’s atmosphere, when a prominence — a large loop of material launched by an eruption on the solar surface — started falling back to the sun’s surface. But before it could make it, the prominence ran into a snarl of magnetic field lines, sparking a magnetic explosion.

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Arc-shaped stream of glowing gas protruding from giant sun with tiny Earth to indicate scale.

A solar prominence (also known as a filament when viewed against the solar disk) is a large, bright feature extending outward from the sun’s surface. Prominences are anchored to the sun’s surface in the photosphere, and extend outwards into the sun’s hot outer atmosphere, called the corona. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months, looping hundreds of thousands of miles into space. This image, from March 2010, shows a solar eruptive prominence, with Earth superimposed for a sense of scale. Image via NASA/SDO.

This new kind of magnetic explosion – called forced magnetic reconnection – has been theoretical until now. According to a NASA statement from December 17, 2019:

Scientists have previously seen the explosive snap and realignment of tangled magnetic field lines on the sun — a process known as magnetic reconnection — but never one that had been triggered by a nearby eruption. The observation, which confirms a decade-old theory, may help scientists understand a key mystery about the sun’s atmosphere, better predict space weather, and may also lead to breakthroughs in the controlled fusion and lab plasma experiments.

Although never seen directly, this kind of forced magnetic reconnection explosion was first theorized 15 years ago. The new observations were published December 17, 2019, in the Astrophysical Journal.

This image shows the sun on May 3, 2012, with the inset showing a close-up of the reconnection event imaged by SDO’s Atmospheric Imaging Assembly instrument, where the signature X-shape is visible. Image via NASA/ SDO/ Abhishek Srivastava/ IIT(BHU).

Read more about the new findings from NASA.

Bottom line: A NASA video explains a new kind of explosion observed from the sun.

Source: On the Observations of Rapid Forced Reconnection in the Solar Corona

Via NASA



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NASA’s Solar Dynamics Observatory (SDO) has observed a kind of magnetic explosion on the sun that scientists have never seen before. The spacecraft spied the explosion in the scorching upper reaches of the sun’s atmosphere, when a prominence — a large loop of material launched by an eruption on the solar surface — started falling back to the sun’s surface. But before it could make it, the prominence ran into a snarl of magnetic field lines, sparking a magnetic explosion.

EarthSky 2020 lunar calendars are available! They make great gifts. Order now. Going fast!

Arc-shaped stream of glowing gas protruding from giant sun with tiny Earth to indicate scale.

A solar prominence (also known as a filament when viewed against the solar disk) is a large, bright feature extending outward from the sun’s surface. Prominences are anchored to the sun’s surface in the photosphere, and extend outwards into the sun’s hot outer atmosphere, called the corona. A prominence forms over timescales of about a day, and stable prominences may persist in the corona for several months, looping hundreds of thousands of miles into space. This image, from March 2010, shows a solar eruptive prominence, with Earth superimposed for a sense of scale. Image via NASA/SDO.

This new kind of magnetic explosion – called forced magnetic reconnection – has been theoretical until now. According to a NASA statement from December 17, 2019:

Scientists have previously seen the explosive snap and realignment of tangled magnetic field lines on the sun — a process known as magnetic reconnection — but never one that had been triggered by a nearby eruption. The observation, which confirms a decade-old theory, may help scientists understand a key mystery about the sun’s atmosphere, better predict space weather, and may also lead to breakthroughs in the controlled fusion and lab plasma experiments.

Although never seen directly, this kind of forced magnetic reconnection explosion was first theorized 15 years ago. The new observations were published December 17, 2019, in the Astrophysical Journal.

This image shows the sun on May 3, 2012, with the inset showing a close-up of the reconnection event imaged by SDO’s Atmospheric Imaging Assembly instrument, where the signature X-shape is visible. Image via NASA/ SDO/ Abhishek Srivastava/ IIT(BHU).

Read more about the new findings from NASA.

Bottom line: A NASA video explains a new kind of explosion observed from the sun.

Source: On the Observations of Rapid Forced Reconnection in the Solar Corona

Via NASA



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Mirfak is Perseus’ brightest star

The constellation Perseus contains the sky’s most celebrated eclipsing binary star, Algol, sometimes called the Demon Star. Algol wins notoriety for its wild swings in brightness, which recur with clock-like precision. However, Mirfak is the easier of the two stars to find, and can serve as your guide star to Algol.

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Star field; Cassiopeia marked, with arrow pointing to two small close-together smudges.

While you’re looking at Perseus, be sure to scan with your binoculars for the Double Cluster. The constellation Cassiopeia can help you find it. The Double Cluster nearly marks the radiant of the Perseid meteor shower. Image via madmiked/ Flickr.

How to find Mirfak. The name Mirfak is derived from Arabic, meaning the Elbow of the Pleiades. In fact, the constellation Perseus lies due north of the Pleiades star cluster, also called the Seven Sisters. In other words, you can find Mirfak and Perseus in between the Pleiades cluster and Polaris, the North Star.

Diagram of constellations Cassiopeia and Perseus with arrow from one to the other.

Look northeast on December evenings for the graceful shape of the constellation Perseus.

You can also take a more direct route to Mirfak, if you’re familiar with the M or W-shaped constellation Cassiopeia the Queen. Draw an imaginary line through the Cassiopeia stars Navi (Gamma Cassiopeiae) and Ruchbah to jump over to Mirfak.

Mirfak is the one Perseus star to stand out in moderately light-polluted skies, as its brilliance matches that of the stars of the famous Big Dipper.

Sixteen randomly scattered bright stars fairly close together.

The Alpha Persei Moving Cluster (Melotte 20). Mirfak is the most prominent member of this grouping of stars. Image via Wikimedia Commons.

Science of Mirfak. At a distance of about 600 light-years, Mirfak lies much farther than the Big Dipper stars, so this star has to be intrinsically very luminous to shine so brightly in our sky. If Mirfak stood at the sun’s distance from Earth, its disk would cover several thousand times more sky. Moreover, Mirfak would shine thousands of times more brightly than our sun.

On a dark night, you might discern a faint array of stars clustering around Mirfak, a bejeweled realm of the heavens that glitters all the more in binoculars. This assemblage of stars is known as the Alpha Persei Moving Group (Melotte 20), of which Mirfak is the most prominent member. Although some feel that this stellar grouping is too dispersed to be called a star cluster, these stars nonetheless move in the same general direction through space, and were born from the same cloud of gas and dust some 30 to 50 million years ago.

Bottom line: How to see the star Mirfak.



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The constellation Perseus contains the sky’s most celebrated eclipsing binary star, Algol, sometimes called the Demon Star. Algol wins notoriety for its wild swings in brightness, which recur with clock-like precision. However, Mirfak is the easier of the two stars to find, and can serve as your guide star to Algol.

EarthSky 2020 lunar calendars are available! They make great gifts. Order now. Going fast!

Star field; Cassiopeia marked, with arrow pointing to two small close-together smudges.

While you’re looking at Perseus, be sure to scan with your binoculars for the Double Cluster. The constellation Cassiopeia can help you find it. The Double Cluster nearly marks the radiant of the Perseid meteor shower. Image via madmiked/ Flickr.

How to find Mirfak. The name Mirfak is derived from Arabic, meaning the Elbow of the Pleiades. In fact, the constellation Perseus lies due north of the Pleiades star cluster, also called the Seven Sisters. In other words, you can find Mirfak and Perseus in between the Pleiades cluster and Polaris, the North Star.

Diagram of constellations Cassiopeia and Perseus with arrow from one to the other.

Look northeast on December evenings for the graceful shape of the constellation Perseus.

You can also take a more direct route to Mirfak, if you’re familiar with the M or W-shaped constellation Cassiopeia the Queen. Draw an imaginary line through the Cassiopeia stars Navi (Gamma Cassiopeiae) and Ruchbah to jump over to Mirfak.

Mirfak is the one Perseus star to stand out in moderately light-polluted skies, as its brilliance matches that of the stars of the famous Big Dipper.

Sixteen randomly scattered bright stars fairly close together.

The Alpha Persei Moving Cluster (Melotte 20). Mirfak is the most prominent member of this grouping of stars. Image via Wikimedia Commons.

Science of Mirfak. At a distance of about 600 light-years, Mirfak lies much farther than the Big Dipper stars, so this star has to be intrinsically very luminous to shine so brightly in our sky. If Mirfak stood at the sun’s distance from Earth, its disk would cover several thousand times more sky. Moreover, Mirfak would shine thousands of times more brightly than our sun.

On a dark night, you might discern a faint array of stars clustering around Mirfak, a bejeweled realm of the heavens that glitters all the more in binoculars. This assemblage of stars is known as the Alpha Persei Moving Group (Melotte 20), of which Mirfak is the most prominent member. Although some feel that this stellar grouping is too dispersed to be called a star cluster, these stars nonetheless move in the same general direction through space, and were born from the same cloud of gas and dust some 30 to 50 million years ago.

Bottom line: How to see the star Mirfak.



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Solstice tale of two cities

Simulation of the line of sunrise as it hits the Eastern Seaboard around the December solstice. Image credit: US Naval Observatory

Simulation of the line of sunrise as it strikes the U.S. eastern seaboard around the December solstice, via the U.S. Naval Observatory.

Around the time of the December solstice, the sun rises at the same time for both New York City and St. Augustine, Florida. On December 21, 2019, the sun rises at 7:16 a.m. Eastern Standard Time (EST). Look above at the simulated view of Earth as the sun is rising over the Atlantic Seaboard of the United States around the time of the December winter solstice. Note that the terminator – the sunrise line – pretty much aligns with the U. S. East Coast, providing a similar sunrise time for coastal dwellers.

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And yet, at this solstice, St. Augustine has about an hour more daylight than New York City. Although the sunrise occurs at the same time for both cities, the sunset happens about an hour later in St. Augustine. (See the sunrise/solar noon/sunset table below.)

Sunrise/solar noon/sunset times on December 21, 2019

City Sunrise Solar Noon Sunset
New York 7:16 a.m. 11:54 a.m. 4:29 p.m.
St. Augustine 7:16 a.m. 12:23 p.m. 5:30 p.m.

Source: Custom Sunset Sunrise Calendar

St. Augustine lodges about 7.5 degrees of longitude to the west of New York City. And our planet takes about 30 minutes to rotate this 7.5 degrees. Therefore, on any day of the year, the sun reaches its noontime position some 30 minutes later in St. Augustine than it does in New York City. For instance, on December 21, 2019, the noonday sun reaches its high point for the day at 11:54 a.m. EST in New York City. In St. Augustine, solar noon comes nearly 30 minutes later, at 12:23 p.m. EST.

St. Augustine resides appreciably south of New York City, so St. Augustine’s morning daylight (from sunrise to solar noon) lasts about 30 minutes longer than it does in New York City on the first day of winter. Thus, the longer period of daylight in St. Augustine cancels out the earlier noontime appearance of the sun in New York City, to give both localities the same sunrise time on the day of the December solstice.

Although New York, NY, and St Augustine, FL, both reside in the Eastern Time Zone, the noonday sun comes 30 minutes later to St. Augustine because it resides 7.5 degrees of longitude to the west of New York City.

Although New York, New York, and St. Augustine, Florida, both reside in the U.S. Eastern time zone, the noonday sun comes 30 minutes later to St. Augustine because it resides 7.5 degrees of longitude to the west of New York City.

Enter the equinoxes

Some three – and nine – months after the December solstice, St. Augustine and New York City receive the same amount of daylight on the days of the March and September equinoxes. On the equinoxes, noontime as well as sunrise and sunset come about 30 minutes later in St. Augustine than they do in New York City. The simulated view of Earth below shows the terminator – the sunrise line – running due north and south on the equinox. Neither the sunrise terminator nor sunset terminator comes anywhere close to aligning with the U.S. East Coast at either equinox.

Sunrise/solar noon/sunset times on March 20, 2020

City Sunrise Solar Noon Sunset
New York 6:58 a.m. 1:03 p.m. 7:09 p.m.
St. Augustine 7:28 a.m. 1:32 p.m. 7:37 p.m.
The terminator - sunrise line - runs due north and south on the equinoxes. The sunset line, though not shown, also runs north and south. Image credit: Earth and Moon Viewer

The terminator – sunrise line – runs due north and south on the equinoxes. The sunset line, though not shown, also runs north and south. Image via Earth and Moon Viewer.

Sunrise/solar noon/sunset times on September 22, 2020

City Sunrise Solar Noon Sunset
New York 6:44 a.m. 12:49 p.m. 6:54 p.m.
St. Augustine 7:14 a.m. 1:18 p.m. 7:22 p.m.

Source: Custom Sunset Sunrise Calendar

Enter the June solstice

Six months after the December solstice, it’s the June summer solstice for the Northern Hemisphere, coming yearly on or near June 21. Now, the situation is reversed from the December solstice, with New York City receiving about an hour more daylight.

Because New York City lies appreciably north of St. Augustine, New York City’s afternoon daylight (from solar noon to sunset) lasts some 30 minutes longer than in St. Augustine on the day of the June summer solstice. Thus, the more daylight in New York City cancels out the later noontime in St. Augustine, to give both localities the same sunset time on the June solstice. (See sunrise/solar noon/sunset table below.)

The terminator - line of sunset - nearly parallels the Atlantic Seaboard on the day of the June solstice.

The terminator – line of sunset – nearly parallels the Atlantic Seaboard on the day of the June solstice.

Look above at the simulated view of Earth as the sun is setting over the Eastern Seaboard of the United States on the day of the summer solstice. Note that the terminator – the sunset line – pretty much coincides with the East Coast, giving a similar sunset time for residents along the Atlantic Seaboard.

From sunrise to sunset on the day of the June solstice, New York City residents enjoy about an hour more daylight than those in St. Augustine. Although the sunset occurs at about the same time for both cities, the sunrise happens an hour earlier in New York City on the day of the summer solstice.

Sunrise/solar noon/sunset times on June 20, 2020

City Sunrise Solar Noon Sunset
New York 5:25 a.m. 12:58 p.m. 8:30 p.m.
St. Augustine 6:25 a.m. 1:27 p.m. 8:29 p.m.

Source: Custom Sunset Sunrise Calendar

Bottom Line: On the day of the December winter solstice, the sun rises at the same time in both St. Augustine, Florida, and New York City, New York, but St. Augustine enjoys an hour more daylight. Six months later, on the day of the June solstice, it’s the sunset that happens at the same time in both places, but with New York City enjoying the extra hour of daylight.



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Simulation of the line of sunrise as it hits the Eastern Seaboard around the December solstice. Image credit: US Naval Observatory

Simulation of the line of sunrise as it strikes the U.S. eastern seaboard around the December solstice, via the U.S. Naval Observatory.

Around the time of the December solstice, the sun rises at the same time for both New York City and St. Augustine, Florida. On December 21, 2019, the sun rises at 7:16 a.m. Eastern Standard Time (EST). Look above at the simulated view of Earth as the sun is rising over the Atlantic Seaboard of the United States around the time of the December winter solstice. Note that the terminator – the sunrise line – pretty much aligns with the U. S. East Coast, providing a similar sunrise time for coastal dwellers.

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And yet, at this solstice, St. Augustine has about an hour more daylight than New York City. Although the sunrise occurs at the same time for both cities, the sunset happens about an hour later in St. Augustine. (See the sunrise/solar noon/sunset table below.)

Sunrise/solar noon/sunset times on December 21, 2019

City Sunrise Solar Noon Sunset
New York 7:16 a.m. 11:54 a.m. 4:29 p.m.
St. Augustine 7:16 a.m. 12:23 p.m. 5:30 p.m.

Source: Custom Sunset Sunrise Calendar

St. Augustine lodges about 7.5 degrees of longitude to the west of New York City. And our planet takes about 30 minutes to rotate this 7.5 degrees. Therefore, on any day of the year, the sun reaches its noontime position some 30 minutes later in St. Augustine than it does in New York City. For instance, on December 21, 2019, the noonday sun reaches its high point for the day at 11:54 a.m. EST in New York City. In St. Augustine, solar noon comes nearly 30 minutes later, at 12:23 p.m. EST.

St. Augustine resides appreciably south of New York City, so St. Augustine’s morning daylight (from sunrise to solar noon) lasts about 30 minutes longer than it does in New York City on the first day of winter. Thus, the longer period of daylight in St. Augustine cancels out the earlier noontime appearance of the sun in New York City, to give both localities the same sunrise time on the day of the December solstice.

Although New York, NY, and St Augustine, FL, both reside in the Eastern Time Zone, the noonday sun comes 30 minutes later to St. Augustine because it resides 7.5 degrees of longitude to the west of New York City.

Although New York, New York, and St. Augustine, Florida, both reside in the U.S. Eastern time zone, the noonday sun comes 30 minutes later to St. Augustine because it resides 7.5 degrees of longitude to the west of New York City.

Enter the equinoxes

Some three – and nine – months after the December solstice, St. Augustine and New York City receive the same amount of daylight on the days of the March and September equinoxes. On the equinoxes, noontime as well as sunrise and sunset come about 30 minutes later in St. Augustine than they do in New York City. The simulated view of Earth below shows the terminator – the sunrise line – running due north and south on the equinox. Neither the sunrise terminator nor sunset terminator comes anywhere close to aligning with the U.S. East Coast at either equinox.

Sunrise/solar noon/sunset times on March 20, 2020

City Sunrise Solar Noon Sunset
New York 6:58 a.m. 1:03 p.m. 7:09 p.m.
St. Augustine 7:28 a.m. 1:32 p.m. 7:37 p.m.
The terminator - sunrise line - runs due north and south on the equinoxes. The sunset line, though not shown, also runs north and south. Image credit: Earth and Moon Viewer

The terminator – sunrise line – runs due north and south on the equinoxes. The sunset line, though not shown, also runs north and south. Image via Earth and Moon Viewer.

Sunrise/solar noon/sunset times on September 22, 2020

City Sunrise Solar Noon Sunset
New York 6:44 a.m. 12:49 p.m. 6:54 p.m.
St. Augustine 7:14 a.m. 1:18 p.m. 7:22 p.m.

Source: Custom Sunset Sunrise Calendar

Enter the June solstice

Six months after the December solstice, it’s the June summer solstice for the Northern Hemisphere, coming yearly on or near June 21. Now, the situation is reversed from the December solstice, with New York City receiving about an hour more daylight.

Because New York City lies appreciably north of St. Augustine, New York City’s afternoon daylight (from solar noon to sunset) lasts some 30 minutes longer than in St. Augustine on the day of the June summer solstice. Thus, the more daylight in New York City cancels out the later noontime in St. Augustine, to give both localities the same sunset time on the June solstice. (See sunrise/solar noon/sunset table below.)

The terminator - line of sunset - nearly parallels the Atlantic Seaboard on the day of the June solstice.

The terminator – line of sunset – nearly parallels the Atlantic Seaboard on the day of the June solstice.

Look above at the simulated view of Earth as the sun is setting over the Eastern Seaboard of the United States on the day of the summer solstice. Note that the terminator – the sunset line – pretty much coincides with the East Coast, giving a similar sunset time for residents along the Atlantic Seaboard.

From sunrise to sunset on the day of the June solstice, New York City residents enjoy about an hour more daylight than those in St. Augustine. Although the sunset occurs at about the same time for both cities, the sunrise happens an hour earlier in New York City on the day of the summer solstice.

Sunrise/solar noon/sunset times on June 20, 2020

City Sunrise Solar Noon Sunset
New York 5:25 a.m. 12:58 p.m. 8:30 p.m.
St. Augustine 6:25 a.m. 1:27 p.m. 8:29 p.m.

Source: Custom Sunset Sunrise Calendar

Bottom Line: On the day of the December winter solstice, the sun rises at the same time in both St. Augustine, Florida, and New York City, New York, but St. Augustine enjoys an hour more daylight. Six months later, on the day of the June solstice, it’s the sunset that happens at the same time in both places, but with New York City enjoying the extra hour of daylight.



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Longest days accompany December solstice

When we say the longest days of the year come each year around the December solstice, we’re talking about the day not as a period of daylight, but as the interval from one solar noon or midday to the next. In December, a day – one rotation of Earth relative to the noonday sun – is about one-half minute longer than the average 24 hours.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

This year, the December solstice arrives on December 22, at 4:19 UTC. For the Central time zone in North America, that’s December 21, at 22:19 (10:19 p.m.). For us in the Northern Hemisphere, the December solstice ushers in our shortest period of daylight and longest period of darkness for the year. And yet – if we consider the length of the day in another light – the longest days of the year come each year in December for the entire globe.

Keep in mind that the clocks on our walls don’t measure the true length of a solar day. To measure the time from one solar noon to the next, you need a sundial. A sundial will tell you the precise moment of local solar noon – when the sun reaches its highest point for the day.

The featured photo at the top of this post shows an analemma. Analemmas show show the sun’s declination – its angular distance from the celestial equator – and the difference (in minutes) between time as measured by the clock and time as measured by the sun. Click here to read more about analemmas.

So it’s December now, and that means one rotation of the Earth relative to the sun – what we call a solar day – is about one-half minute longer than the average 24 hours, for the entire globe.

Days are always longer – as measured from one solar noon to the next – than 24 hours around the solstices, and less than 24 hours around the the equinoxes.

The days are at their longest now – for the whole globe – because we’re closer to the sun on the December solstice than we are at the June solstice. Earth’s perihelion – closest point to the sun – always comes in early January. When we’re closest to the sun, our planet is moving a little faster than average in its orbit. That means our planet is traveling through space a little farther than average each day. The result is that Earth has to rotate a little more on its axis for the sun to return to its noontime position. Hence the longer solar day.

Half a minute longer doesn’t sound like much, but the difference adds up. For instance, two weeks before the December solstice, noontime comes about seven minutes earlier by the clock than on the December solstice. And then two weeks after the December solstice, noon by the clock comes about seven minutes later later by the clock than on the December solstice itself. Because the clock and sun are most out of sync right now, some befuddling phenomena cause people to scratch their heads at this time of year.

Click here to find out the clock time for solar noon at your locality, remembering to check the Solar noon box.

In the Northern Hemisphere, the year’s earliest sunset precedes the December winter solstice, and the year’s latest sunrise comes after the December winter solstice.

In the Southern Hemisphere, the year’s earliest sunrise precedes the December summer solstice, and the year’s latest sunset comes after the December summer solstice.

Although the solstice brings the shortest/longest period of daylight, the earliest sunset/sunrise always comes before the solstice, and latest sunrise/sunset always comes afterwards.

The fact that we’re closest to the sun in early January also means that Northern Hemisphere winter (Southern Hemisphere summer) is the shortest of the four seasons. At the same time … ‘tis the season of bountifully long solar days.

Sundial outside Adler Planetarium in Chicago, Illinois. A sundial lets you measure the time from one solar noon – when the sun reaches its highest point for the day – to the next. Image via Ben+Sam.

Bottom line: As measured from one solar noon to the next, December has the longest days – the longest day/night cycle – for the whole Earth.

Want to see 2018’s brightest comet? How to see comet 46P/Wirtanen

Read more: Earliest sunsets (or sunrises) always happen before the winter (or summer) solstice

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!



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When we say the longest days of the year come each year around the December solstice, we’re talking about the day not as a period of daylight, but as the interval from one solar noon or midday to the next. In December, a day – one rotation of Earth relative to the noonday sun – is about one-half minute longer than the average 24 hours.

EarthSky lunar calendars are cool! They make great gifts. Order now. Going fast!

This year, the December solstice arrives on December 22, at 4:19 UTC. For the Central time zone in North America, that’s December 21, at 22:19 (10:19 p.m.). For us in the Northern Hemisphere, the December solstice ushers in our shortest period of daylight and longest period of darkness for the year. And yet – if we consider the length of the day in another light – the longest days of the year come each year in December for the entire globe.

Keep in mind that the clocks on our walls don’t measure the true length of a solar day. To measure the time from one solar noon to the next, you need a sundial. A sundial will tell you the precise moment of local solar noon – when the sun reaches its highest point for the day.

The featured photo at the top of this post shows an analemma. Analemmas show show the sun’s declination – its angular distance from the celestial equator – and the difference (in minutes) between time as measured by the clock and time as measured by the sun. Click here to read more about analemmas.

So it’s December now, and that means one rotation of the Earth relative to the sun – what we call a solar day – is about one-half minute longer than the average 24 hours, for the entire globe.

Days are always longer – as measured from one solar noon to the next – than 24 hours around the solstices, and less than 24 hours around the the equinoxes.

The days are at their longest now – for the whole globe – because we’re closer to the sun on the December solstice than we are at the June solstice. Earth’s perihelion – closest point to the sun – always comes in early January. When we’re closest to the sun, our planet is moving a little faster than average in its orbit. That means our planet is traveling through space a little farther than average each day. The result is that Earth has to rotate a little more on its axis for the sun to return to its noontime position. Hence the longer solar day.

Half a minute longer doesn’t sound like much, but the difference adds up. For instance, two weeks before the December solstice, noontime comes about seven minutes earlier by the clock than on the December solstice. And then two weeks after the December solstice, noon by the clock comes about seven minutes later later by the clock than on the December solstice itself. Because the clock and sun are most out of sync right now, some befuddling phenomena cause people to scratch their heads at this time of year.

Click here to find out the clock time for solar noon at your locality, remembering to check the Solar noon box.

In the Northern Hemisphere, the year’s earliest sunset precedes the December winter solstice, and the year’s latest sunrise comes after the December winter solstice.

In the Southern Hemisphere, the year’s earliest sunrise precedes the December summer solstice, and the year’s latest sunset comes after the December summer solstice.

Although the solstice brings the shortest/longest period of daylight, the earliest sunset/sunrise always comes before the solstice, and latest sunrise/sunset always comes afterwards.

The fact that we’re closest to the sun in early January also means that Northern Hemisphere winter (Southern Hemisphere summer) is the shortest of the four seasons. At the same time … ‘tis the season of bountifully long solar days.

Sundial outside Adler Planetarium in Chicago, Illinois. A sundial lets you measure the time from one solar noon – when the sun reaches its highest point for the day – to the next. Image via Ben+Sam.

Bottom line: As measured from one solar noon to the next, December has the longest days – the longest day/night cycle – for the whole Earth.

Want to see 2018’s brightest comet? How to see comet 46P/Wirtanen

Read more: Earliest sunsets (or sunrises) always happen before the winter (or summer) solstice

A planisphere is virtually indispensable for beginning stargazers. Order your EarthSky Planisphere today!



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Dogs process numerical quantities in similar brain region as humans

Emory neuroscientist Gregory Berns is researching how dogs think and view the world. (Photo by Kay Hinton)

Dogs spontaneously process basic numerical quantities, using a distinct part of their brains that corresponds closely to number-responsive neural regions in humans, finds a study at Emory University.

Biology Letters published the results, which suggest that a common neural mechanism has been deeply conserved across mammalian evolution.

“Our work not only shows that dogs use a similar part of their brain to process numbers of objects as humans do — it shows that they don’t need to be trained to do it,” says Gregory Berns, Emory professor of psychology and senior author of the study.

“Understanding neural mechanisms — both in humans and across species — gives us insights into both how our brains evolved over time and how they function now,” says co-author Stella Lourenco, an associate professor of psychology at Emory.

Such insights, Lourenco adds, may one day lead to practical applications such as treating brain abnormalities and improving artificial intelligence systems.

Lauren Aulet, A PhD candidate in Lourenco's lab, is first author of the study.

Read the full story here.

Related:
Scientists chase mystery of how dogs process words
Do dogs prefer praise or food?
Scent of the familiar: You may linger like perfume in your dog's brain

from eScienceCommons https://ift.tt/2Z1dWOe
Emory neuroscientist Gregory Berns is researching how dogs think and view the world. (Photo by Kay Hinton)

Dogs spontaneously process basic numerical quantities, using a distinct part of their brains that corresponds closely to number-responsive neural regions in humans, finds a study at Emory University.

Biology Letters published the results, which suggest that a common neural mechanism has been deeply conserved across mammalian evolution.

“Our work not only shows that dogs use a similar part of their brain to process numbers of objects as humans do — it shows that they don’t need to be trained to do it,” says Gregory Berns, Emory professor of psychology and senior author of the study.

“Understanding neural mechanisms — both in humans and across species — gives us insights into both how our brains evolved over time and how they function now,” says co-author Stella Lourenco, an associate professor of psychology at Emory.

Such insights, Lourenco adds, may one day lead to practical applications such as treating brain abnormalities and improving artificial intelligence systems.

Lauren Aulet, A PhD candidate in Lourenco's lab, is first author of the study.

Read the full story here.

Related:
Scientists chase mystery of how dogs process words
Do dogs prefer praise or food?
Scent of the familiar: You may linger like perfume in your dog's brain

from eScienceCommons https://ift.tt/2Z1dWOe