Northern lights and north star. Steve?

Steven Bellavia wrote on June 13, 2018:

I was at the dark sky site, Cherry Springs State Park, Pennsylvania last night and got to see a very unusual northern lights display! It was a spike, pointing directly at Polaris, the North Star.

Could it be a sighting the recently studied phenomenon called a Strong Thermal Emission Velocity Enhancement, or STEVE, which is the nickname originally given to this light by aurora watchers? The Atlantic described the phenomenon this way:

This new feature differs from the long-studied ‘classical’ aurora in several ways. It can be seen from much closer to the equator than its more famous twin, and it emanates from a spot twice as high in the sky. It was also first described and studied not by cultivated researchers—like those who coined the moniker aurora borealis—but by devoted amateurs. They were among the first to photograph the ethereal streak of purple light, and they were the first to give it a name.

Read more from NASA: The aurora named Steve

By the way, Steven Bellavia also sent a short timelapse, which is below:

Bottom line: A June 2018 photo of northern lights pointing to the north star, possibly Steve.

Source: New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere

from EarthSky https://ift.tt/2l4ASZT

Steven Bellavia wrote on June 13, 2018:

I was at the dark sky site, Cherry Springs State Park, Pennsylvania last night and got to see a very unusual northern lights display! It was a spike, pointing directly at Polaris, the North Star.

Could it be a sighting the recently studied phenomenon called a Strong Thermal Emission Velocity Enhancement, or STEVE, which is the nickname originally given to this light by aurora watchers? The Atlantic described the phenomenon this way:

This new feature differs from the long-studied ‘classical’ aurora in several ways. It can be seen from much closer to the equator than its more famous twin, and it emanates from a spot twice as high in the sky. It was also first described and studied not by cultivated researchers—like those who coined the moniker aurora borealis—but by devoted amateurs. They were among the first to photograph the ethereal streak of purple light, and they were the first to give it a name.

Read more from NASA: The aurora named Steve

By the way, Steven Bellavia also sent a short timelapse, which is below:

Bottom line: A June 2018 photo of northern lights pointing to the north star, possibly Steve.

Source: New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere

from EarthSky https://ift.tt/2l4ASZT

All you need to know: June solstice 2018

The sunset has been making its way north, as illustrated in this 2016 photo composite by Abhijit Juvekar.

The June solstice – your signal to celebrate summer in the Northern Hemisphere and winter in the Southern Hemisphere – is coming up on June 21, 2018, at 10:07 UTC. That’s 5:97 a.m. CDT in North America on June 21. Translate UTC to your time. For us in the Northern Hemisphere, this solstice marks the longest day of the year. Early dawns. Long days. Late sunsets. Short nights. The sun at its height each day, as it crosses the sky. Meanwhile, south of the equator, winter begins.

Waiting for dawn to arrive at Stonehenge, summer solstice 2005. Image via Andrew Dunn/ Wikimedia Commons. Read more about summer solstice at Stonehenge.

What is a solstice? Ancient cultures knew that the sun’s path across the sky, the length of daylight, and the location of the sunrise and sunset all shifted in a regular way throughout the year.

They built monuments, such as Stonehenge, to follow the sun’s yearly progress.

Today, we know that the solstice is an astronomical event, caused by Earth’s tilt on its axis and its motion in orbit around the sun.

Because Earth doesn’t orbit upright. Instead, our world is tilted on its axis by 23-and-a-half degrees, Earth’s Northern and Southern Hemispheres trade places in receiving the sun’s light and warmth most directly.

At the June solstice, Earth is positioned in its orbit so that our world’s North Pole is leaning most toward the sun. As seen from Earth, the sun is directly overhead at noon 23 1/2 degrees north of the equator, at an imaginary line encircling the globe known as the Tropic of Cancer – named after the constellation Cancer the Crab. This is as far north as the sun ever gets.

All locations north of the equator have days longer than 12 hours at the June solstice. Meanwhile, all locations south of the equator have days shorter than 12 hours.

The red line shows the Tropic of Cancer. As seen from this line of latitude, the sun appears overhead at noon on the June solstice. Image via Wikimedia Commons.

When is the solstice where I live? The solstice takes place place on June 21, 2018 at 10:07 UTC. That’s 5:07 a.m. CDT in North America on June 20.

A solstice happens at the same instant for all of us, everywhere on Earth. To find the time of the solstice in your location, you have to translate to your time zone.

Here’s an example of how to do that. In the central United States, for those of us using Central Daylight Time, we subtract five hours from Universal Time. That’s how we get 5:07 a.m. CDT as the time of the 2018 June solstice (10:07 UTC on June 21 minus 5 equals 5:07 a.m. CDT on June 21).

Want to know the time in your location? Check out EarthSky’s article How do I translate Universal Time into my time? And just remember: you’re translating from 10:07 UTC, June 21.

Sunset via EarthSky Facebook friend Lucy Bee in Dallas.

Where should I look to see signs of the solstice in nature? Everywhere. For all of Earth’s creatures, nothing is so fundamental as the length of the day. After all, the sun is the ultimate source of almost all light and warmth on Earth’s surface.

If you live in the Northern Hemisphere, you might notice the early dawns and late sunsets, and the high arc of the sun across the sky each day. You might see how high the sun appears in the sky at local noon. And be sure to look at your noontime shadow. Around the time of the solstice, it’s your shortest noontime shadow of the year.

If you’re a person who’s tuned in to the out-of-doors, you know the peaceful, comforting feeling that accompanies these signs and signals of the year’s longest day.

Watching the solstice sunrise. Photo via Sarah Little-Knitwitz, Glastonbury Tor, Somerset, U.K.

Is the solstice the first day of summer? No world body has designated an official day to start each new season, and different schools of thought or traditions define the seasons in different ways.

In meteorology, for example, summer begins on June 1. And every school child knows that summer starts when the last school bell of the year rings.

Yet today is perhaps the most widely recognized day upon which summer begins in the Northern Hemisphere and upon which winter begins on the southern half of Earth’s globe. There’s nothing official about it, but it’s such a long-held tradition that we all recognize it to be so.

Day and night sides of Earth at the instant of June 2018 solstice (2018 June 21 at 10:07 UTC). It’s sunrise in the Americas, noon in Africa, and sunset in Japan and Indonesia. Worldwide map via the US Naval Observatory.

It has been universal among humans to treasure this time of warmth and light.

For us in the modern world, the solstice is a time to recall the reverence and understanding that early people had for the sky. Some 5,000 years ago, people placed huge stones in a circle on a broad plain in what’s now England and aligned them with the June solstice sunrise.

We may never comprehend the full significance of Stonehenge. But we do know that knowledge of this sort wasn’t isolated to just one part of the world. Around the same time Stonehenge was being constructed in England, two great pyramids and then the Sphinx were built on Egyptian sands. If you stood at the Sphinx on the summer solstice and gazed toward the two pyramids, you’d see the sun set exactly between them.

Image Credit: Flickr user Ludwig Simbajon

How does it end up hotter later in the summer, if June has the longest day? People often ask:

If the June solstice brings the longest day, why do we experience the hottest weather in late July and August?

This effect is called the lag of the seasons. It’s the same reason it’s hotter in mid-afternoon than at noontime. Earth just takes a while to warm up after a long winter. Even in June, ice and snow still blanket the ground in some places. The sun has to melt the ice – and warm the oceans – and then we feel the most sweltering summer heat.

Ice and snow have been melting since spring began. Meltwater and rainwater have been percolating down through snow on tops of glaciers.

But the runoff from glaciers isn’t as great now as it’ll be in another month, even though sunlight is striking the northern hemisphere most directly around now.

So wait another month for the hottest weather. It’ll come when the days are already beginning to shorten again, as Earth continues to move in orbit around the sun, bringing us closer to another winter.

And so the cycle continues.

Hello summer solstice!

Bottom line: The 2018 June happens on June 21 at 10:07 UTC. That’s 5:07 a.m. CDT in North America. This solstice – which marks the beginning of summer in the Northern Hemisphere – marks the sun’s most northerly point in Earth’s sky. It’s an event celebrated by people throughout the ages.

Visit EarthSky Tonight for easy-to-use night sky charts and info. Updated daily.

Celebrate the summer solstice as the Chinese philosophers did

Why the hottest weather isn’t on the longest day

from EarthSky https://ift.tt/1fl9JNp

The sunset has been making its way north, as illustrated in this 2016 photo composite by Abhijit Juvekar.

The June solstice – your signal to celebrate summer in the Northern Hemisphere and winter in the Southern Hemisphere – is coming up on June 21, 2018, at 10:07 UTC. That’s 5:97 a.m. CDT in North America on June 21. Translate UTC to your time. For us in the Northern Hemisphere, this solstice marks the longest day of the year. Early dawns. Long days. Late sunsets. Short nights. The sun at its height each day, as it crosses the sky. Meanwhile, south of the equator, winter begins.

Waiting for dawn to arrive at Stonehenge, summer solstice 2005. Image via Andrew Dunn/ Wikimedia Commons. Read more about summer solstice at Stonehenge.

What is a solstice? Ancient cultures knew that the sun’s path across the sky, the length of daylight, and the location of the sunrise and sunset all shifted in a regular way throughout the year.

They built monuments, such as Stonehenge, to follow the sun’s yearly progress.

Today, we know that the solstice is an astronomical event, caused by Earth’s tilt on its axis and its motion in orbit around the sun.

Because Earth doesn’t orbit upright. Instead, our world is tilted on its axis by 23-and-a-half degrees, Earth’s Northern and Southern Hemispheres trade places in receiving the sun’s light and warmth most directly.

At the June solstice, Earth is positioned in its orbit so that our world’s North Pole is leaning most toward the sun. As seen from Earth, the sun is directly overhead at noon 23 1/2 degrees north of the equator, at an imaginary line encircling the globe known as the Tropic of Cancer – named after the constellation Cancer the Crab. This is as far north as the sun ever gets.

All locations north of the equator have days longer than 12 hours at the June solstice. Meanwhile, all locations south of the equator have days shorter than 12 hours.

The red line shows the Tropic of Cancer. As seen from this line of latitude, the sun appears overhead at noon on the June solstice. Image via Wikimedia Commons.

When is the solstice where I live? The solstice takes place place on June 21, 2018 at 10:07 UTC. That’s 5:07 a.m. CDT in North America on June 20.

A solstice happens at the same instant for all of us, everywhere on Earth. To find the time of the solstice in your location, you have to translate to your time zone.

Here’s an example of how to do that. In the central United States, for those of us using Central Daylight Time, we subtract five hours from Universal Time. That’s how we get 5:07 a.m. CDT as the time of the 2018 June solstice (10:07 UTC on June 21 minus 5 equals 5:07 a.m. CDT on June 21).

Want to know the time in your location? Check out EarthSky’s article How do I translate Universal Time into my time? And just remember: you’re translating from 10:07 UTC, June 21.

Sunset via EarthSky Facebook friend Lucy Bee in Dallas.

Where should I look to see signs of the solstice in nature? Everywhere. For all of Earth’s creatures, nothing is so fundamental as the length of the day. After all, the sun is the ultimate source of almost all light and warmth on Earth’s surface.

If you live in the Northern Hemisphere, you might notice the early dawns and late sunsets, and the high arc of the sun across the sky each day. You might see how high the sun appears in the sky at local noon. And be sure to look at your noontime shadow. Around the time of the solstice, it’s your shortest noontime shadow of the year.

If you’re a person who’s tuned in to the out-of-doors, you know the peaceful, comforting feeling that accompanies these signs and signals of the year’s longest day.

Watching the solstice sunrise. Photo via Sarah Little-Knitwitz, Glastonbury Tor, Somerset, U.K.

Is the solstice the first day of summer? No world body has designated an official day to start each new season, and different schools of thought or traditions define the seasons in different ways.

In meteorology, for example, summer begins on June 1. And every school child knows that summer starts when the last school bell of the year rings.

Yet today is perhaps the most widely recognized day upon which summer begins in the Northern Hemisphere and upon which winter begins on the southern half of Earth’s globe. There’s nothing official about it, but it’s such a long-held tradition that we all recognize it to be so.

Day and night sides of Earth at the instant of June 2018 solstice (2018 June 21 at 10:07 UTC). It’s sunrise in the Americas, noon in Africa, and sunset in Japan and Indonesia. Worldwide map via the US Naval Observatory.

It has been universal among humans to treasure this time of warmth and light.

For us in the modern world, the solstice is a time to recall the reverence and understanding that early people had for the sky. Some 5,000 years ago, people placed huge stones in a circle on a broad plain in what’s now England and aligned them with the June solstice sunrise.

We may never comprehend the full significance of Stonehenge. But we do know that knowledge of this sort wasn’t isolated to just one part of the world. Around the same time Stonehenge was being constructed in England, two great pyramids and then the Sphinx were built on Egyptian sands. If you stood at the Sphinx on the summer solstice and gazed toward the two pyramids, you’d see the sun set exactly between them.

Image Credit: Flickr user Ludwig Simbajon

How does it end up hotter later in the summer, if June has the longest day? People often ask:

If the June solstice brings the longest day, why do we experience the hottest weather in late July and August?

This effect is called the lag of the seasons. It’s the same reason it’s hotter in mid-afternoon than at noontime. Earth just takes a while to warm up after a long winter. Even in June, ice and snow still blanket the ground in some places. The sun has to melt the ice – and warm the oceans – and then we feel the most sweltering summer heat.

Ice and snow have been melting since spring began. Meltwater and rainwater have been percolating down through snow on tops of glaciers.

But the runoff from glaciers isn’t as great now as it’ll be in another month, even though sunlight is striking the northern hemisphere most directly around now.

So wait another month for the hottest weather. It’ll come when the days are already beginning to shorten again, as Earth continues to move in orbit around the sun, bringing us closer to another winter.

And so the cycle continues.

Hello summer solstice!

Bottom line: The 2018 June happens on June 21 at 10:07 UTC. That’s 5:07 a.m. CDT in North America. This solstice – which marks the beginning of summer in the Northern Hemisphere – marks the sun’s most northerly point in Earth’s sky. It’s an event celebrated by people throughout the ages.

Visit EarthSky Tonight for easy-to-use night sky charts and info. Updated daily.

Celebrate the summer solstice as the Chinese philosophers did

Why the hottest weather isn’t on the longest day

from EarthSky https://ift.tt/1fl9JNp

Coyote and apple in rural New Mexico

Coyote and apple. Richard Hasbrouck captured this shot in the summer of 2012. Canon EOS Mk III, Canon 24-105 mm @ 105 mm, f/5.6, 1/200 sec, ISO 400.

Yesterday, we posted an image of a coyote in a park, but of course they’re in rural locations, too. Richard Hasbrouck wrote:

Taken in our yard in the rural mountain village of Truchas, New Mexico. When I looked out the window there was ‘Trixter,’ the name Navajos give to coyote. He was looking over some of our fallen apples. Fortunately, my camera was at hand so I was able to document him departing with an apple in his mouth. This was a one-time event.

Thank you, Richard!

from EarthSky https://ift.tt/2JQbjd3

Coyote and apple. Richard Hasbrouck captured this shot in the summer of 2012. Canon EOS Mk III, Canon 24-105 mm @ 105 mm, f/5.6, 1/200 sec, ISO 400.

Yesterday, we posted an image of a coyote in a park, but of course they’re in rural locations, too. Richard Hasbrouck wrote:

Taken in our yard in the rural mountain village of Truchas, New Mexico. When I looked out the window there was ‘Trixter,’ the name Navajos give to coyote. He was looking over some of our fallen apples. Fortunately, my camera was at hand so I was able to document him departing with an apple in his mouth. This was a one-time event.

Thank you, Richard!

from EarthSky https://ift.tt/2JQbjd3

New image of the Tarantula Nebula

See an annotated version of this image here. Image via ESO.

Astronomers using the VLT Survey Telescope at the European Southern Observatory’s Paranal Observatory in Chile, captured this very detailed new image of the Tarantula Nebula – aka 30 Doradus – one of the most famous sights of Earth’s southern skies.

The Tarantula Nebula – at the top of the image above – is about 160,000 light-years away. It spans more than 1,000 light-years. Astronomers know it as an energetic star-forming region in the Large Magellanic Cloud, a satellite galaxy to our Milky Way.

Read more and see an annotated version of this image from ESO

Bottom line: New image of the Tarantula Nebula from ESO.

from EarthSky https://ift.tt/2t3zKt3

See an annotated version of this image here. Image via ESO.

Astronomers using the VLT Survey Telescope at the European Southern Observatory’s Paranal Observatory in Chile, captured this very detailed new image of the Tarantula Nebula – aka 30 Doradus – one of the most famous sights of Earth’s southern skies.

The Tarantula Nebula – at the top of the image above – is about 160,000 light-years away. It spans more than 1,000 light-years. Astronomers know it as an energetic star-forming region in the Large Magellanic Cloud, a satellite galaxy to our Milky Way.

Read more and see an annotated version of this image from ESO

Bottom line: New image of the Tarantula Nebula from ESO.

from EarthSky https://ift.tt/2t3zKt3

Earliest sunrises before summer solstice

Top of post: June sunrise in Sea Bright, New Jersey, via Steve Scanlon Photography.

At mid-northern latitudes in the Northern Hemisphere, your earliest sunrises of the year happen around mid-June, despite the fact that the summer solstice – the year’s longest day – is still about a week away. And if you live at middle latitudes in the Southern Hemisphere, your earliest sunsets take place around now, even though the winter solstice – your shortest day – isn’t for another week.

For the Northern Hemisphere: For those of you who are privileged to be outdoors before one of these early sunrises, you’ll find some of the most beautiful dawn twilights of the year.

For the Southern Hemisphere: If you’re someone who relishes the day’s light, as many do, you might be glad of the sunsets will soon be shifting later!

The exact date of earliest sunrise (and earliest sunset) varies with latitude. At 40^o north latitude – the latitude of, say, Philadelphia in Pennsylvania – the earliest sunrise of the year will happen on June 14. For that same latitude, the latest sunset of the year will fall on or near June 27. Meanwhile, the longest day of the year – the day containing the greatest amount of daylight, overall – comes on the solstice on June 21.

So it is for other Northern Hemisphere latitudes. The dates of earliest sunrise and latest sunset don’t coincide exactly with the solstice. Appreciably south of Philadelphia’s latitude, the earliest sunrise has already come and gone (in late May or early June) and the latest sunset occurs at a later date (sometimes as late as July). In Hawaii, for instance, the earliest sunrise precedes the June solstice by about 2 weeks, and the latest sunset comes about 2 weeks after. Farther north, the earliest sunrise and latest sunset happen closer to the June solstice. Check it out at your latitude, using links on our almanac page.

The earliest sunrises come before the summer solstice because the day is more than 24 hours long at this time of the year. In the Southern Hemisphere, the earliest sunsets of the year come before the winter solstice for the same reason.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

See full size | Sunrise over Currituck, North Carolina. Credit: GregDiesel Landscape Photography

In June, the day (as measured by successive returns of the midday sun) is nearly 1/4 minute longer than 24 hours. Hence, the midday sun (solar noon) comes later by the clock on the June solstice than it does one week before. Therefore, the sunrise and sunset times also come later by the clock, as the tables below help to explain.

For Philadelphia (40^o north latitude)

 

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 14	5:31 a.m.	1:00 p.m.	8:31 p.m.	14h 59m 15s
June 21	5:32 a.m.	1:02 p.m.	8:32 p.m.	15h 00m 35s

 

 

For Valdivia, Chile (40^o south latitude)

 

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 14	8:12 a.m.	12:53 p.m.	5:34 p.m.	9h 21m 56s
June 21	8:14 a.m.	12:54 p.m.	5:35 p.m.	9h 20m 39s

 

Source: timeanddate.com

The primary reason for the earliest sunrise preceding the summer solstice (and the earliest sunset preceding the winter solstice) is the inclination of the Earth’s rotational axis. The earliest sunrise or sunset would take place before the solstice even if the Earth went around the sun in a circular orbit.

However, the Earth’s elliptical orbit does affect the severity of the phenomenon. At the June solstice, Earth in its orbit is rather close to aphelion – its farthest point from the sun – which lessens the effect. At the December solstice, Earth is rather close to perihelion – its closest point to the sun – which accentuates it.

At middle latitudes, the earliest sunrise/sunset comes about one week before the June summer/winter solstice, and the latest sunset/sunrise about one week after the June solstice.

Yet, at the other end of the year, at middle latitudes, the earliest sunset/sunrise comes about two weeks before the December winter/summer solstice, and the latest sunrise/sunset about two weeks after the December solstice.

Early sunrise in Sweden via Per Ola Wiberg

Early sunrise by Flickr user Raffee

Bottom line: Are you an early riser? If so – if you live in the Northern Hemisphere – you might know your earliest sunrises of the year are happening now. Southern Hemisphere? Your earliest sunsets are around now.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us

from EarthSky https://ift.tt/1lM9VQO

Top of post: June sunrise in Sea Bright, New Jersey, via Steve Scanlon Photography.

At mid-northern latitudes in the Northern Hemisphere, your earliest sunrises of the year happen around mid-June, despite the fact that the summer solstice – the year’s longest day – is still about a week away. And if you live at middle latitudes in the Southern Hemisphere, your earliest sunsets take place around now, even though the winter solstice – your shortest day – isn’t for another week.

For the Northern Hemisphere: For those of you who are privileged to be outdoors before one of these early sunrises, you’ll find some of the most beautiful dawn twilights of the year.

For the Southern Hemisphere: If you’re someone who relishes the day’s light, as many do, you might be glad of the sunsets will soon be shifting later!

The exact date of earliest sunrise (and earliest sunset) varies with latitude. At 40^o north latitude – the latitude of, say, Philadelphia in Pennsylvania – the earliest sunrise of the year will happen on June 14. For that same latitude, the latest sunset of the year will fall on or near June 27. Meanwhile, the longest day of the year – the day containing the greatest amount of daylight, overall – comes on the solstice on June 21.

So it is for other Northern Hemisphere latitudes. The dates of earliest sunrise and latest sunset don’t coincide exactly with the solstice. Appreciably south of Philadelphia’s latitude, the earliest sunrise has already come and gone (in late May or early June) and the latest sunset occurs at a later date (sometimes as late as July). In Hawaii, for instance, the earliest sunrise precedes the June solstice by about 2 weeks, and the latest sunset comes about 2 weeks after. Farther north, the earliest sunrise and latest sunset happen closer to the June solstice. Check it out at your latitude, using links on our almanac page.

The earliest sunrises come before the summer solstice because the day is more than 24 hours long at this time of the year. In the Southern Hemisphere, the earliest sunsets of the year come before the winter solstice for the same reason.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

See full size | Sunrise over Currituck, North Carolina. Credit: GregDiesel Landscape Photography

In June, the day (as measured by successive returns of the midday sun) is nearly 1/4 minute longer than 24 hours. Hence, the midday sun (solar noon) comes later by the clock on the June solstice than it does one week before. Therefore, the sunrise and sunset times also come later by the clock, as the tables below help to explain.

For Philadelphia (40^o north latitude)

 

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 14	5:31 a.m.	1:00 p.m.	8:31 p.m.	14h 59m 15s
June 21	5:32 a.m.	1:02 p.m.	8:32 p.m.	15h 00m 35s

 

 

For Valdivia, Chile (40^o south latitude)

 

Date	Sunrise	Midday (Solar Noon)	Sunset	Daylight Hours
June 14	8:12 a.m.	12:53 p.m.	5:34 p.m.	9h 21m 56s
June 21	8:14 a.m.	12:54 p.m.	5:35 p.m.	9h 20m 39s

 

Source: timeanddate.com

The primary reason for the earliest sunrise preceding the summer solstice (and the earliest sunset preceding the winter solstice) is the inclination of the Earth’s rotational axis. The earliest sunrise or sunset would take place before the solstice even if the Earth went around the sun in a circular orbit.

However, the Earth’s elliptical orbit does affect the severity of the phenomenon. At the June solstice, Earth in its orbit is rather close to aphelion – its farthest point from the sun – which lessens the effect. At the December solstice, Earth is rather close to perihelion – its closest point to the sun – which accentuates it.

At middle latitudes, the earliest sunrise/sunset comes about one week before the June summer/winter solstice, and the latest sunset/sunrise about one week after the June solstice.

Yet, at the other end of the year, at middle latitudes, the earliest sunset/sunrise comes about two weeks before the December winter/summer solstice, and the latest sunrise/sunset about two weeks after the December solstice.

Early sunrise in Sweden via Per Ola Wiberg

Early sunrise by Flickr user Raffee

Bottom line: Are you an early riser? If so – if you live in the Northern Hemisphere – you might know your earliest sunrises of the year are happening now. Southern Hemisphere? Your earliest sunsets are around now.

EarthSky astronomy kits are perfect for beginners. Order today from the EarthSky store

Donate: Your support means the world to us

from EarthSky https://ift.tt/1lM9VQO

The strange case for life in other universes

Our galaxy, and the universe in general, formed in a way that is ideal to support life. Could other universes also be home to life of some kind? Image via Yuri Beletsky Nightscapes.

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When it comes to searching for life elsewhere in the universe, we think of the rovers on Mars, or of sending probes to Jupiter’s moon Europa or Saturn’s moon Enceladus. Or we think of looking for habitable exoplanets or exomoons. The universe we’re in feels infinite with possibilities, but – in contemplating alien life – could we go beyond even our own universe? Writing at NBC News Mach on May 28, 2018, Seth Shostak of the SETI Institute in Mountain View, California, ponders this very theoretical, yet exciting idea of the possibility of life in parallel universes.

Shostak’s article is based on two related papers, published in May, in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society. He focuses on explanations related to a hypothetical substance in our universe known as dark energy. The effect of dark energy appears to be a faster expansion of our universe over time.

The idea of parallel universes isn’t new. You find it in many fields of thought. But, in the physics community, the debate about this concept – which is sometimes called the multiverse hypothesis – has heated up in recent years. As Shostak explained in his Mach article:

The idea that other universes might exist arises from the realization that the Big Bang might not have been a unique event but a common one. How common? Stanford University physicists Andrei Linde and Vitaly Vanchurin have estimated that the number of unique parallel universes – ones that are independent of the cosmos you know and adore – could be written as a one followed by 10 thousand trillion zeroes. That’s not a number that has a name, and certainly not one you will ever encounter in the real world. I figure it would require 10 billion notebooks just to write this number down.

So, to paraphrase Jodie Foster’s character in the movie Contact, if our cosmos is the only one with life, then that’s an awful waste of universes.

How does dark energy relate to these possible parallel universes?

In their previous studies, physicists have concluded that our universe might have less dark energy than other universes, if those universes do exist. Parallel universes might have so much dark energy that stars and planets cannot form. In other words, in most universes, it might be the case that more dark energy leads to even faster expansion of the universe, preventing star- and planet-formation, making life unlikely.

The new studies, from scientists in the U.K., Australia and Holland, suggests dark energy doesn’t play a such a crucial role in whether parallel universes can support life, or not. As Shostak said:

Using computer models, the research team found they could vary the strength of dark energy from zero to several hundred times its value in our universe, and everything remained copacetic. Dark energy didn’t need to be any particular strength for galaxies and stars to form.

From the vantage point of life in other universes, that might be good news.

Is our universe just one of many?

There are still other factors to consider however, such as differences in nuclear or gravitational forces. Some other universes may still be completely sterile, unlike ours which has formed in ways that are ideal for life to exist. Shostak explained:

[Our universe’s] physical properties are remarkably suitable for the existence of life. If the forces that hold atoms together were even a bit different, the atomic reactions that power the stars wouldn’t work, and our cosmos would consist of nothing but hydrogen. Tweak those constants another way, and stars would burn themselves out so quickly that there would have been no time for the evolution of microbes, dinosaurs, or you. If the strength of gravity were just slightly altered, our universe would have either expanded too rapidly after the Big Bang for stars and galaxies to form – or would have collapsed in a Big Crunch.

It was also thought that dark matter was essential for galaxies to form, but, recently, the 10-billion-year-old galaxy NGC 1052-DF2, 65 million light-years away in the constellation Cetus, contains 400 times less dark matter than had been expected. That finding was published on March 28, 2018 in the peer-reviewed journal Nature. As Pieter van Dokkum at Yale University commented:

You don’t expect a galaxy to have no dark matter because dark matter is not something a galaxy can just opt out of.

All of this is conjecture, informed by the tools of modern physics and by high-powered computer modeling. It is speculative, but interesting food for thought. Parallel universes, dark energy and dark matter are the kinds of subjects which have long been relegated to science fiction, but today’s science is shedding new light on just how incredible the cosmos really is.

Thus, while we’re still searching for evidence of alien life in our own universe, the possibility of an almost infinite number of such universes – some inhabited – is truly mind-blowing.

Scanning electron microscope image of a purported bacteria-like fossil in the Martian meteorite Allan Hills 84001. We are searching for evidence of alien life in our solar system and beyond. What about other universes? Image via NASA.

Bottom line: As discussed previously at EarthSky, new research has suggested that the Big Bang may have been only one of countless others, that parallel universes might exist, but that life might not be possible in those other universes. Writing at NBC News Mach, Seth Shostak of the SETI Institute provides some insights on new studies, suggesting that might not be so.

Sources:
The impact of dark energy on galaxy formation. What does the future of our Universe hold?

Galaxy Formation Efficiency and the Multiverse Explanation of the Cosmological Constant with EAGLE Simulations

Via NBC News Mach

Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.

from EarthSky https://ift.tt/2MlfsnV

Our galaxy, and the universe in general, formed in a way that is ideal to support life. Could other universes also be home to life of some kind? Image via Yuri Beletsky Nightscapes.

Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.

When it comes to searching for life elsewhere in the universe, we think of the rovers on Mars, or of sending probes to Jupiter’s moon Europa or Saturn’s moon Enceladus. Or we think of looking for habitable exoplanets or exomoons. The universe we’re in feels infinite with possibilities, but – in contemplating alien life – could we go beyond even our own universe? Writing at NBC News Mach on May 28, 2018, Seth Shostak of the SETI Institute in Mountain View, California, ponders this very theoretical, yet exciting idea of the possibility of life in parallel universes.

Shostak’s article is based on two related papers, published in May, in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society. He focuses on explanations related to a hypothetical substance in our universe known as dark energy. The effect of dark energy appears to be a faster expansion of our universe over time.

The idea of parallel universes isn’t new. You find it in many fields of thought. But, in the physics community, the debate about this concept – which is sometimes called the multiverse hypothesis – has heated up in recent years. As Shostak explained in his Mach article:

The idea that other universes might exist arises from the realization that the Big Bang might not have been a unique event but a common one. How common? Stanford University physicists Andrei Linde and Vitaly Vanchurin have estimated that the number of unique parallel universes – ones that are independent of the cosmos you know and adore – could be written as a one followed by 10 thousand trillion zeroes. That’s not a number that has a name, and certainly not one you will ever encounter in the real world. I figure it would require 10 billion notebooks just to write this number down.

So, to paraphrase Jodie Foster’s character in the movie Contact, if our cosmos is the only one with life, then that’s an awful waste of universes.

How does dark energy relate to these possible parallel universes?

In their previous studies, physicists have concluded that our universe might have less dark energy than other universes, if those universes do exist. Parallel universes might have so much dark energy that stars and planets cannot form. In other words, in most universes, it might be the case that more dark energy leads to even faster expansion of the universe, preventing star- and planet-formation, making life unlikely.

The new studies, from scientists in the U.K., Australia and Holland, suggests dark energy doesn’t play a such a crucial role in whether parallel universes can support life, or not. As Shostak said:

Using computer models, the research team found they could vary the strength of dark energy from zero to several hundred times its value in our universe, and everything remained copacetic. Dark energy didn’t need to be any particular strength for galaxies and stars to form.

From the vantage point of life in other universes, that might be good news.

Is our universe just one of many?

There are still other factors to consider however, such as differences in nuclear or gravitational forces. Some other universes may still be completely sterile, unlike ours which has formed in ways that are ideal for life to exist. Shostak explained:

[Our universe’s] physical properties are remarkably suitable for the existence of life. If the forces that hold atoms together were even a bit different, the atomic reactions that power the stars wouldn’t work, and our cosmos would consist of nothing but hydrogen. Tweak those constants another way, and stars would burn themselves out so quickly that there would have been no time for the evolution of microbes, dinosaurs, or you. If the strength of gravity were just slightly altered, our universe would have either expanded too rapidly after the Big Bang for stars and galaxies to form – or would have collapsed in a Big Crunch.

It was also thought that dark matter was essential for galaxies to form, but, recently, the 10-billion-year-old galaxy NGC 1052-DF2, 65 million light-years away in the constellation Cetus, contains 400 times less dark matter than had been expected. That finding was published on March 28, 2018 in the peer-reviewed journal Nature. As Pieter van Dokkum at Yale University commented:

You don’t expect a galaxy to have no dark matter because dark matter is not something a galaxy can just opt out of.

All of this is conjecture, informed by the tools of modern physics and by high-powered computer modeling. It is speculative, but interesting food for thought. Parallel universes, dark energy and dark matter are the kinds of subjects which have long been relegated to science fiction, but today’s science is shedding new light on just how incredible the cosmos really is.

Thus, while we’re still searching for evidence of alien life in our own universe, the possibility of an almost infinite number of such universes – some inhabited – is truly mind-blowing.

Scanning electron microscope image of a purported bacteria-like fossil in the Martian meteorite Allan Hills 84001. We are searching for evidence of alien life in our solar system and beyond. What about other universes? Image via NASA.

Bottom line: As discussed previously at EarthSky, new research has suggested that the Big Bang may have been only one of countless others, that parallel universes might exist, but that life might not be possible in those other universes. Writing at NBC News Mach, Seth Shostak of the SETI Institute provides some insights on new studies, suggesting that might not be so.

Sources:
The impact of dark energy on galaxy formation. What does the future of our Universe hold?

Galaxy Formation Efficiency and the Multiverse Explanation of the Cosmological Constant with EAGLE Simulations

Via NBC News Mach

Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.

from EarthSky https://ift.tt/2MlfsnV

Coyotes in the park

Coyote enjoying a Sunday morning in the park. Apparently, there were 2 of them, and they had this videographer surrounded. Video still via Steven A. Sweet of Lunar 101-Moon Book.

Steven A. Sweet of Etobicoke, Ontario, Canada – who runs the Facebook page Lunar 101-Moon Book – frequently shares his moon photos with us. He posted the video below at EarthSky on Facebook on June 10, 2018. It shows what’s become a common subject, if not necessarily a common sight, to those of us who live in cities. Urban coyotes are now a fact of life for city dwellers.

Thank you, Steven!

Bottom line: Coyotes have become a common feature within cities.

Read more: Urban wildlife is here to stay

Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.

from EarthSky https://ift.tt/2l29dIW

Coyote enjoying a Sunday morning in the park. Apparently, there were 2 of them, and they had this videographer surrounded. Video still via Steven A. Sweet of Lunar 101-Moon Book.

Steven A. Sweet of Etobicoke, Ontario, Canada – who runs the Facebook page Lunar 101-Moon Book – frequently shares his moon photos with us. He posted the video below at EarthSky on Facebook on June 10, 2018. It shows what’s become a common subject, if not necessarily a common sight, to those of us who live in cities. Urban coyotes are now a fact of life for city dwellers.

Thank you, Steven!

Bottom line: Coyotes have become a common feature within cities.

Read more: Urban wildlife is here to stay

Help EarthSky keep going! Please donate what you can to our annual crowd-funding campaign.

from EarthSky https://ift.tt/2l29dIW