How snowflakes get their shape

Photo by Kimberly Smith.

The shapes of snowflakes are influenced by the temperature and humidity of the atmosphere. Snowflakes form in the atmosphere when cold water droplets freeze onto dust particles. Depending on the temperature and humidity of the air where the snowflakes form, the resulting ice crystals will grow into a myriad of different shapes.

Wilson Bentley (1865–1931) from Jericho, Vermont, was the first person to capture photographs of snowflakes through the use of a microscope attached to a camera. His collection of 5,000 snowflake images introduced many people to the astounding diversity of snow crystals.

William Bentley photographing snowflakes. Image via Snowflake Bentley.

In 1951, scientists from an organization now called the International Association of Cyrospheric Sciences (IACS) devised a classification system that characterized snowflakes into 10 basic shapes. These shapes include the stellar crystals that many people are familiar with, as well as lesser-known snowflake forms such as capped columns. The IACS classification system is still in use today although there are other more complex classification systems as well.

Classification of snow crystals in 1951 by the International Association of Cryospheric Sciences. Image via Vincent J. Schaefer.

Kenneth Libbrecht, Professor of Physics at the California Institute of Technology, has made extensive observations of how water molecules get incorporated into snow crystals. In his research, he observed that the most intricate snowflake patterns are formed when there is moisture in the air. Snowflakes produced in drier conditions tend to have simpler shapes.

According to Libbrecht’s research, temperature also has a large effect on the formation of snowflakes. Snowflakes formed in temperatures below -7.6 degrees Fahrenheit (-22 degrees C) consist primarily of simple crystal plates and columns. Meanwhile, snowflakes with extensive branching patterns are formed in warmer temperatures.

Check out Libbrecht’s website, SnowCrystal.com. It’s truly a wealth of information about snowflakes.

Effects of temperature and humidity on snowflake formation. Image via Kenneth Libbrecht.

Fiona M. Donnelly captured these snowflakes in Smiths Falls, Ontario, on January 3, 2018.

Bottom line: Snowflake shape is influenced by temperature and humidity. The most intricate snowflake patterns are typically formed during warm and wet conditions.

See more photos: A few favorites from the EarthSky community

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

from EarthSky http://bit.ly/2Tk5HsY

Photo by Kimberly Smith.

The shapes of snowflakes are influenced by the temperature and humidity of the atmosphere. Snowflakes form in the atmosphere when cold water droplets freeze onto dust particles. Depending on the temperature and humidity of the air where the snowflakes form, the resulting ice crystals will grow into a myriad of different shapes.

Wilson Bentley (1865–1931) from Jericho, Vermont, was the first person to capture photographs of snowflakes through the use of a microscope attached to a camera. His collection of 5,000 snowflake images introduced many people to the astounding diversity of snow crystals.

William Bentley photographing snowflakes. Image via Snowflake Bentley.

In 1951, scientists from an organization now called the International Association of Cyrospheric Sciences (IACS) devised a classification system that characterized snowflakes into 10 basic shapes. These shapes include the stellar crystals that many people are familiar with, as well as lesser-known snowflake forms such as capped columns. The IACS classification system is still in use today although there are other more complex classification systems as well.

Classification of snow crystals in 1951 by the International Association of Cryospheric Sciences. Image via Vincent J. Schaefer.

Kenneth Libbrecht, Professor of Physics at the California Institute of Technology, has made extensive observations of how water molecules get incorporated into snow crystals. In his research, he observed that the most intricate snowflake patterns are formed when there is moisture in the air. Snowflakes produced in drier conditions tend to have simpler shapes.

According to Libbrecht’s research, temperature also has a large effect on the formation of snowflakes. Snowflakes formed in temperatures below -7.6 degrees Fahrenheit (-22 degrees C) consist primarily of simple crystal plates and columns. Meanwhile, snowflakes with extensive branching patterns are formed in warmer temperatures.

Check out Libbrecht’s website, SnowCrystal.com. It’s truly a wealth of information about snowflakes.

Effects of temperature and humidity on snowflake formation. Image via Kenneth Libbrecht.

Fiona M. Donnelly captured these snowflakes in Smiths Falls, Ontario, on January 3, 2018.

Bottom line: Snowflake shape is influenced by temperature and humidity. The most intricate snowflake patterns are typically formed during warm and wet conditions.

See more photos: A few favorites from the EarthSky community

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

from EarthSky http://bit.ly/2Tk5HsY

A few favorite snowflake photos

View larger at EarthSky Community Photos. | John Entwistle caught this snowflake on January 13, 2019, and wrote: “The beauty of an individual snowflake that fell on the Jersey Shore, New Jersey.”

If you want to take snowflake photos and need a few helpful hints, check out: Michael Peres on how to photograph snowflakes

How snowflakes get their shapes

View larger at EarthSky Community Photos. | Neeti Kumthekar in the Basking Ridge area of Somerset County, New Jersey, captured this image on January 18, 2019, and wrote: “Snowflake on car windshield!”

View at EarthSky Community Photos. | Our friend Karl Diefenderfer wrote: “Photogenic snowflakes from winter of 2018.”

View larger at EarthSky Community Photos. | Perian Moore in Bath, Maine, captured this image on January 11, 2019, and wrote: “This was a frostflake on my truck window. Extended my tripod as to its full length 6 feet and used a ladder. I am only 5 foot 2.
It was a heavy frost. And I captured many great images. Some look 3d.” Thank you, Perian!

View larger at EarthSky Community Photos. | Merielle Kazakoff in Christina Lake, B.C., Canada, caught this image on December 18, 2018, and wrote: “We had one of those light and fluffy snowfalls where the snowflakes are perfect to see and photograph. I love the way you can see the matrix of flakes caught together when you look close. They are so delicate and lovely!” Thank you, Merielle.

View larger at EarthSky Community Photos. | These aren’t snowflakes, but they are ice crystals – grown from saltwater – captured by Patty Mede in East Islip, New York, back on February 6, 2016.

View larger at EarthSky Community Photos. | Andres Rengifo in Selden, Long Island, saw these crystals on his car windshield Dec. 6, 2018. Taken with an iPhone X.

Kris Orr captured this snowflake in Mercer County, New Jersey, in December 2017.

Photo by Sonia Khanvilkar.

Fiona M. Donnelly captured these snowflakes in Smiths Falls, Ontario, on January 3, 2018.

“The first snow of the year!” by Mac Mierzwinski.

Photo via Morgan Breeze.

Photo by Kimberly Smith.

Photo by Eileen Claffey. She wrote, “Stuck to the slider window. Fast and furious and very cold storm.”

Kelly Holtman Wagner took this photo of snowflakes on her deck in Boylston, Massachusetts.

“Here’s one I took back in 2009,” wrote Adam Brown.

New England blizzard snowflake. Photo by Linda Roy Hadwen from New Hampshire.

Kevin Travino said, “I wanted to share this one I took off my windshield one night after work while warming up my car. The picture is not edited, just cropped to show the snowflake better. I took the picture with a Samsung Galaxy S3.”

Snowflake from Trillemarka, Sigdal. Photo by Jånn Peter Normann.

Denise Talley said,”I managed to capture a few snowflakes this morning during our wonderful snow storm! We got some much needed moisture and i got some good practice with my new lens :) Need to work on my focusing, perhaps my glasses would serve a good purpose here?”

Bottom line: Photos of snowflakes by EarthSky friends.

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

from EarthSky http://bit.ly/2HJ1zlg

View larger at EarthSky Community Photos. | John Entwistle caught this snowflake on January 13, 2019, and wrote: “The beauty of an individual snowflake that fell on the Jersey Shore, New Jersey.”

If you want to take snowflake photos and need a few helpful hints, check out: Michael Peres on how to photograph snowflakes

How snowflakes get their shapes

View larger at EarthSky Community Photos. | Neeti Kumthekar in the Basking Ridge area of Somerset County, New Jersey, captured this image on January 18, 2019, and wrote: “Snowflake on car windshield!”

View at EarthSky Community Photos. | Our friend Karl Diefenderfer wrote: “Photogenic snowflakes from winter of 2018.”

View larger at EarthSky Community Photos. | Perian Moore in Bath, Maine, captured this image on January 11, 2019, and wrote: “This was a frostflake on my truck window. Extended my tripod as to its full length 6 feet and used a ladder. I am only 5 foot 2.
It was a heavy frost. And I captured many great images. Some look 3d.” Thank you, Perian!

View larger at EarthSky Community Photos. | Merielle Kazakoff in Christina Lake, B.C., Canada, caught this image on December 18, 2018, and wrote: “We had one of those light and fluffy snowfalls where the snowflakes are perfect to see and photograph. I love the way you can see the matrix of flakes caught together when you look close. They are so delicate and lovely!” Thank you, Merielle.

View larger at EarthSky Community Photos. | These aren’t snowflakes, but they are ice crystals – grown from saltwater – captured by Patty Mede in East Islip, New York, back on February 6, 2016.

View larger at EarthSky Community Photos. | Andres Rengifo in Selden, Long Island, saw these crystals on his car windshield Dec. 6, 2018. Taken with an iPhone X.

Kris Orr captured this snowflake in Mercer County, New Jersey, in December 2017.

Photo by Sonia Khanvilkar.

Fiona M. Donnelly captured these snowflakes in Smiths Falls, Ontario, on January 3, 2018.

“The first snow of the year!” by Mac Mierzwinski.

Photo via Morgan Breeze.

Photo by Kimberly Smith.

Photo by Eileen Claffey. She wrote, “Stuck to the slider window. Fast and furious and very cold storm.”

Kelly Holtman Wagner took this photo of snowflakes on her deck in Boylston, Massachusetts.

“Here’s one I took back in 2009,” wrote Adam Brown.

New England blizzard snowflake. Photo by Linda Roy Hadwen from New Hampshire.

Kevin Travino said, “I wanted to share this one I took off my windshield one night after work while warming up my car. The picture is not edited, just cropped to show the snowflake better. I took the picture with a Samsung Galaxy S3.”

Snowflake from Trillemarka, Sigdal. Photo by Jånn Peter Normann.

Denise Talley said,”I managed to capture a few snowflakes this morning during our wonderful snow storm! We got some much needed moisture and i got some good practice with my new lens :) Need to work on my focusing, perhaps my glasses would serve a good purpose here?”

Bottom line: Photos of snowflakes by EarthSky friends.

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

from EarthSky http://bit.ly/2HJ1zlg

New warning about Greenland ice melt

Greenland ice via Ohio State University.

Greenland ice is melting faster than scientists previously thought — and will likely lead to faster-than-expected sea level rise — according to a new study. This study comes from an international team of scientists and was published January 21, 2019, in the peer-reviewed Proceedings of the National Academy of Sciences.

Scientists concerned about sea level rise have long focused on Greenland’s southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting into seawater. But here is what’s unusual about the new study. It found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland’s southwest region, which is mostly devoid of large glaciers.

That melting means that – in the southwestern part of Greenland – growing rivers of water are streaming into the ocean during the summer. Michael Bevis, a professor of geodynamics at Ohio State University, is the study’s lead author. Bevis said in a statement:

We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers. But now we recognize a second serious problem: Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea.

The findings suggest that southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise, Bevis said. This scenario could have serious implications for coastal U.S. cities, including New York and Miami, as well as island nations that are particularly vulnerable to rising sea levels. Bevis added that, from his perspective as a scientist who studies Greenland ice melt, there is no turning back:

The only thing we can do is adapt and mitigate further global warming. It’s too late for there to be no effect. This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point.

Iceberg in Greenland. Image via © mikhail79spb/Fotolia.

Climate scientists and glaciologists have been monitoring the Greenland ice sheet as a whole since the 2002 launch of NASA’s GRACE (Gravity Recovery and Climate Experiment) mission. GRACE – and now a follow-up mission called GRACE-FO, launched in 2018 – consists of twin satellites that have the capability of tracking Earth’s water movement. According to NASA, the satellites can:

… monitor changes in underground water storage, the amount of water in large lakes and rivers, soil moisture, ice sheets and glaciers, and sea level caused by the addition of water to the ocean.

Data from GRACE showed that – between 2002 and 2016 – Greenland lost approximately 280 gigatons of ice per year, equivalent to 0.03 inches (.7 mm) of sea level rise each year.

But the rate of ice loss across the island was far from steady.

For the new study, the team used data from GRACE and from GPS stations scattered around Greenland’s coast to identify changes in ice mass. The patterns they found show an alarming trend, they said. By 2012, ice was being lost at nearly four times the rate observed in 2003. The researchers were surprised to discover that this acceleration was focused in southwest Greenland, a part of the island that previously hadn’t been known to be losing ice that rapidly.

Bevis said a natural weather phenomenon – the North Atlantic Oscillation, which brings warmer air to West Greenland, as well as clearer skies and more solar radiation — was building on human-caused climate change to cause unprecedented levels of melting and runoff. Global atmospheric warming enhances summertime melting, especially in the southwest. The North Atlantic Oscillation is a natural – if erratic – cycle that causes ice to melt under normal circumstances. When combined with man-made global warming, though, the effects are supercharged. Bevis said:

These oscillations have been happening forever. So why only now are they causing this massive melt? It’s because the atmosphere is, at its baseline, warmer … Global warming has brought summertime temperatures in a significant portion of Greenland close to the melting point, and the North Atlantic Oscillation has provided the extra push that caused large areas of ice to melt.

Scientists have understood Greenland to be one of the Earth’s major contributors to sea-level rise mostly because of its glaciers. But these new findings, Bevis said, show that scientists need to be watching the island’s snowpack and ice fields more closely, especially in and near southwest Greenland. He said:

We’re going to see faster and faster sea level rise for the foreseeable future. Once you hit that tipping point, the only question is: How severe does it get?

Bottom line: A new study finds that Greenland ice is melting four times faster than 15 years ago. The findings suggest that key southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise.

Source: Accelerating changes in ice mass within Greenland, and the ice sheet’s sensitivity to atmospheric forcing

Via Ohio State University

EarthSky 2019 lunar calendars are cool! Order now. They’re going fast!

from EarthSky http://bit.ly/2UoBUzM

Greenland ice via Ohio State University.

Greenland ice is melting faster than scientists previously thought — and will likely lead to faster-than-expected sea level rise — according to a new study. This study comes from an international team of scientists and was published January 21, 2019, in the peer-reviewed Proceedings of the National Academy of Sciences.

Scientists concerned about sea level rise have long focused on Greenland’s southeast and northwest regions, where large glaciers stream iceberg-sized chunks of ice into the Atlantic Ocean. Those chunks float away, eventually melting into seawater. But here is what’s unusual about the new study. It found that the largest sustained ice loss from early 2003 to mid-2013 came from Greenland’s southwest region, which is mostly devoid of large glaciers.

That melting means that – in the southwestern part of Greenland – growing rivers of water are streaming into the ocean during the summer. Michael Bevis, a professor of geodynamics at Ohio State University, is the study’s lead author. Bevis said in a statement:

We knew we had one big problem with increasing rates of ice discharge by some large outlet glaciers. But now we recognize a second serious problem: Increasingly, large amounts of ice mass are going to leave as meltwater, as rivers that flow into the sea.

The findings suggest that southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise, Bevis said. This scenario could have serious implications for coastal U.S. cities, including New York and Miami, as well as island nations that are particularly vulnerable to rising sea levels. Bevis added that, from his perspective as a scientist who studies Greenland ice melt, there is no turning back:

The only thing we can do is adapt and mitigate further global warming. It’s too late for there to be no effect. This is going to cause additional sea level rise. We are watching the ice sheet hit a tipping point.

Iceberg in Greenland. Image via © mikhail79spb/Fotolia.

Climate scientists and glaciologists have been monitoring the Greenland ice sheet as a whole since the 2002 launch of NASA’s GRACE (Gravity Recovery and Climate Experiment) mission. GRACE – and now a follow-up mission called GRACE-FO, launched in 2018 – consists of twin satellites that have the capability of tracking Earth’s water movement. According to NASA, the satellites can:

… monitor changes in underground water storage, the amount of water in large lakes and rivers, soil moisture, ice sheets and glaciers, and sea level caused by the addition of water to the ocean.

Data from GRACE showed that – between 2002 and 2016 – Greenland lost approximately 280 gigatons of ice per year, equivalent to 0.03 inches (.7 mm) of sea level rise each year.

But the rate of ice loss across the island was far from steady.

For the new study, the team used data from GRACE and from GPS stations scattered around Greenland’s coast to identify changes in ice mass. The patterns they found show an alarming trend, they said. By 2012, ice was being lost at nearly four times the rate observed in 2003. The researchers were surprised to discover that this acceleration was focused in southwest Greenland, a part of the island that previously hadn’t been known to be losing ice that rapidly.

Bevis said a natural weather phenomenon – the North Atlantic Oscillation, which brings warmer air to West Greenland, as well as clearer skies and more solar radiation — was building on human-caused climate change to cause unprecedented levels of melting and runoff. Global atmospheric warming enhances summertime melting, especially in the southwest. The North Atlantic Oscillation is a natural – if erratic – cycle that causes ice to melt under normal circumstances. When combined with man-made global warming, though, the effects are supercharged. Bevis said:

These oscillations have been happening forever. So why only now are they causing this massive melt? It’s because the atmosphere is, at its baseline, warmer … Global warming has brought summertime temperatures in a significant portion of Greenland close to the melting point, and the North Atlantic Oscillation has provided the extra push that caused large areas of ice to melt.

Scientists have understood Greenland to be one of the Earth’s major contributors to sea-level rise mostly because of its glaciers. But these new findings, Bevis said, show that scientists need to be watching the island’s snowpack and ice fields more closely, especially in and near southwest Greenland. He said:

We’re going to see faster and faster sea level rise for the foreseeable future. Once you hit that tipping point, the only question is: How severe does it get?

Bottom line: A new study finds that Greenland ice is melting four times faster than 15 years ago. The findings suggest that key southwest Greenland, which previously had not been considered a serious threat, will likely become a major future contributor to sea level rise.

Source: Accelerating changes in ice mass within Greenland, and the ice sheet’s sensitivity to atmospheric forcing

Via Ohio State University

EarthSky 2019 lunar calendars are cool! Order now. They’re going fast!

from EarthSky http://bit.ly/2UoBUzM

2019 SkS Weekly Climate Change & Global Warming Digest #4

Story of the Week... Editorial of the Week... Toon of the Week... Quote of the Week... SkS in the News... Coming Soon on SkS... Climate Feedback Reviews... SkS Week in Review... Poster of the Week...

Story of the Week...

Teenage activist takes School Strikes 4 Climate Action to Davos

Protest by 16-year-old Greta Thunberg snowballs to last day of World Economic Forum

 

Swedish youth climate activist Greta Thunberg at the World Economic Forum in Davos, eastern Switzerland. Photograph: Fabrice Coffrini/AFP/Getty Images 

The 16-year-old activist behind the fast-growing School Strikes 4 Climate Action has taken her campaign to the streets of Davos, to confront world leaders and business chiefs about the global emissions crisis.

Greta Thunberg, whose solo protest outside Sweden’s parliament has snowballed across the globe, will join a strike by Swiss schoolchildren in the ski resort on Friday – the final day of the World Economic Forum.

Thunberg travelled by train for 32 hours to reach Davos, and spent Wednesday night camped with climate scientists on the mountain slopes – where temperatures plunged to -18C.

Having already addressed the UN Climate Change COP 24 conference, Thunberg is rapidly becoming the voice for a generation who are demanding urgent action to slow the rise in global temperatures.

As she travelled down Davos’s funicular railway from the Arctic Base Camp – while more than 30,000 students were striking in Belgium - Thunberg said the rapid growth of her movement was “incredible”.

“There have been climate strikes, involving students and also adults, on every continent except Antarctica. It has involved tens of thousands of children.”

Teenage activist takes School Strikes 4 Climate Action to Davos by Graeme Wearden & Damian Carrington, Environment, Guardian, Jan 24, 2019

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Editorial of the Week...

This Could Be The Biggest Scandal Of The Climate Change Era

The world is headed for up to 5 degrees Celsius (9 F) of global warming above pre-industrial levels by 2100, which would lead to devastating consequences for billions of people. Credit: Anton Petrus via Getty Images

Governments and businesses habitually set out emergency response plans to protect their economies, jobs, cities and other crucial assets from potential disaster. Yet when it comes to climate change ― the biggest, most urgent threat the world faces ― there is no emergency plan.

On the issue of our lifetime, countries can agree very little. The World Economic Forum’s Global Risks Report 2019 published last Tuesday found that increasing divisions between the world’s major powers is the most urgent global risk we face because it stymies vital collective action on climate change.

Instead of action, we see delays, rejections and avoidance, as December’s United Nations climate summit in Katowice, Poland, so acutely reminded us. The event, which brought together world leaders, scientists, campaigners and the private sector, settled most of the rules needed to ensure countries follow the climate pledges they have made to date. What it failed to do is push countries to step up their targets for cutting greenhouse gas emissions ― currently the only viable way to prevent climate breakdown. The Middle East, the U.S. and Russia refused to even welcome landmark scientific predictions on climate change, signaling their intention to continue blocking progress.

This Could Be The Biggest Scandal Of The Climate Change Era, Opinion by Sandrine Dixson-Declève & Anders Wijkman, Huffington Post, Jan 23, 2019

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Toon of the Week...

 

Hat tip to Stop Climate Denial Facebook page.

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Quotes of the Week...

But the tone has shifted. The feeling is more dire. I don’t know what kids are supposed to do with the sobering fact that their planet is changing for the worse.

According to Laura Kastner, a clinical psychologist and professor in the psychology department and the department of psychiatry and behavioral sciences at the University of Washington, the way to teach kids about environmental issues is not by overwhelming them with data or presenting them with projected outcomes they can see no way of changing. It’s by being realistic with kids and also teaching them agency and action.

It’s what Kastner describes as the “both-and.” The idea of first acknowledging that, yes, climate change is happening, and there are things we can do to help. “We really are going to have to deal with this, and there is so much to do, so let’s get to work,” she said. “We want to be responsible and smart and informed about what’s happening, and we want to be hopeful and agentic.”

Heather Price, an atmospheric chemist, climate scientist and chemistry instructor at North Seattle College, who has presented climate science to members of Congress, says that whenever she gives a talk about rising temperatures, ocean acidification and mass extinctions, she always spends at least a quarter of her time discussing the areas where scientists see hope and how people are already altering the trajectory. For example, the capacity of renewable energy in the United Kingdom has surpassed that of fossil fuels for the first time, and in the United States, electric car sales were up 81 percent in 2018 over sales in 2017. Price knows the science is depressing. “But,” she says, “it’s not on the science side where the good things are happening. It’s on the mitigation, on the solutions.”

Ways to help kids cope with — and help combat — climate change by Ronit Feinglass Plank, Lifestyles, Washington Post, Jan 22, 2019 

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SkS in the News...

[To be added.] 

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Coming Soon on SkS...

[To be added.] 

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Climate Feedback Reviews...

How credible were 2018’s most popular climate articles?

Summary

To investigate whether last year’s most “viral” climate change stories misled the people who read them, we asked scientists to evaluate a list of top articles (as we did last year). In November, we searched Buzzsumo for the climate articles[1] with the most shares and interactions—as many as 1.2 million in the top spot—selecting the top 10 that focused on verifiable statements about climate science. (One more story entered the list in December.) Two stories did not receive any reviews, but all the evaluations and comments we collected can be found below.

Compared to last year’s top 10, there is a notable lack of low credibility stories. Two stories garnered mixed reviews from scientists. In one case, this was an article detailing false claims about sea level rise made by politicians, in which some reviewers felt the article simply wasn’t clear enough in its corrections. But there were no articles from partisan outlets presenting inaccurate rejections of climate system at the top in 2018. Instead, the list was dominated by major news outlets—with the exception of the top story, which was published by the local FOX station in St. Louis.

This leads to an interesting question we unfortunately cannot answer at this stage: is this improvement in the credibility of the most-shared articles the result of recent changes to social media algorithms or just chance?

Almost half of the stories in this list cover major IPCC and US National Climate Assessment reports released last year. It also seems clear that people are interested in learning about (or commenting on) the environmental impacts of diet. The #4 story of 2017 was about the greenhouse gas emissions associated with beef production, and two of 2018’s top stories are on the same topic.

Several of the remaining stories featured dramatic headlines on events related to climate trends—things like winter warm spells at the North Pole or the 400th consecutive month warmer than the 20th century average. The most popular story (titled “NASA releases time-lapse of the disappearing Arctic polar ice cap”) was actually an article on the 2017 global surface temperature ranking that included a NASA animation of Arctic sea ice changes over the years.

 

 

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SkS Week in Review...  

• 2019 SkS Weekly Climate Change & Global Warming News Roundup #4 by John Hartz
• New research, January 14-20, 2019 by Ari Jokimäki
• SkS Analogy 17 - Lotteries, evaporation, and superstorms by Evan & jg
• State of the climate: How the world warmed in 2018 by Zeke Hausfather, (Carbon Brief)
• 2019 SkS Weekly Climate Change & Global Warming Digest #3  by John Hartz

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Poster of the Week...

 

from Skeptical Science http://bit.ly/2TibJKO

Story of the Week... Editorial of the Week... Toon of the Week... Quote of the Week... SkS in the News... Coming Soon on SkS... Climate Feedback Reviews... SkS Week in Review... Poster of the Week...

Story of the Week...

Teenage activist takes School Strikes 4 Climate Action to Davos

Protest by 16-year-old Greta Thunberg snowballs to last day of World Economic Forum

 

Swedish youth climate activist Greta Thunberg at the World Economic Forum in Davos, eastern Switzerland. Photograph: Fabrice Coffrini/AFP/Getty Images 

The 16-year-old activist behind the fast-growing School Strikes 4 Climate Action has taken her campaign to the streets of Davos, to confront world leaders and business chiefs about the global emissions crisis.

Greta Thunberg, whose solo protest outside Sweden’s parliament has snowballed across the globe, will join a strike by Swiss schoolchildren in the ski resort on Friday – the final day of the World Economic Forum.

Thunberg travelled by train for 32 hours to reach Davos, and spent Wednesday night camped with climate scientists on the mountain slopes – where temperatures plunged to -18C.

Having already addressed the UN Climate Change COP 24 conference, Thunberg is rapidly becoming the voice for a generation who are demanding urgent action to slow the rise in global temperatures.

As she travelled down Davos’s funicular railway from the Arctic Base Camp – while more than 30,000 students were striking in Belgium - Thunberg said the rapid growth of her movement was “incredible”.

“There have been climate strikes, involving students and also adults, on every continent except Antarctica. It has involved tens of thousands of children.”

Teenage activist takes School Strikes 4 Climate Action to Davos by Graeme Wearden & Damian Carrington, Environment, Guardian, Jan 24, 2019

---

Editorial of the Week...

This Could Be The Biggest Scandal Of The Climate Change Era

The world is headed for up to 5 degrees Celsius (9 F) of global warming above pre-industrial levels by 2100, which would lead to devastating consequences for billions of people. Credit: Anton Petrus via Getty Images

Governments and businesses habitually set out emergency response plans to protect their economies, jobs, cities and other crucial assets from potential disaster. Yet when it comes to climate change ― the biggest, most urgent threat the world faces ― there is no emergency plan.

On the issue of our lifetime, countries can agree very little. The World Economic Forum’s Global Risks Report 2019 published last Tuesday found that increasing divisions between the world’s major powers is the most urgent global risk we face because it stymies vital collective action on climate change.

Instead of action, we see delays, rejections and avoidance, as December’s United Nations climate summit in Katowice, Poland, so acutely reminded us. The event, which brought together world leaders, scientists, campaigners and the private sector, settled most of the rules needed to ensure countries follow the climate pledges they have made to date. What it failed to do is push countries to step up their targets for cutting greenhouse gas emissions ― currently the only viable way to prevent climate breakdown. The Middle East, the U.S. and Russia refused to even welcome landmark scientific predictions on climate change, signaling their intention to continue blocking progress.

This Could Be The Biggest Scandal Of The Climate Change Era, Opinion by Sandrine Dixson-Declève & Anders Wijkman, Huffington Post, Jan 23, 2019

---

Toon of the Week...

 

Hat tip to Stop Climate Denial Facebook page.

---

Quotes of the Week...

But the tone has shifted. The feeling is more dire. I don’t know what kids are supposed to do with the sobering fact that their planet is changing for the worse.

According to Laura Kastner, a clinical psychologist and professor in the psychology department and the department of psychiatry and behavioral sciences at the University of Washington, the way to teach kids about environmental issues is not by overwhelming them with data or presenting them with projected outcomes they can see no way of changing. It’s by being realistic with kids and also teaching them agency and action.

It’s what Kastner describes as the “both-and.” The idea of first acknowledging that, yes, climate change is happening, and there are things we can do to help. “We really are going to have to deal with this, and there is so much to do, so let’s get to work,” she said. “We want to be responsible and smart and informed about what’s happening, and we want to be hopeful and agentic.”

Heather Price, an atmospheric chemist, climate scientist and chemistry instructor at North Seattle College, who has presented climate science to members of Congress, says that whenever she gives a talk about rising temperatures, ocean acidification and mass extinctions, she always spends at least a quarter of her time discussing the areas where scientists see hope and how people are already altering the trajectory. For example, the capacity of renewable energy in the United Kingdom has surpassed that of fossil fuels for the first time, and in the United States, electric car sales were up 81 percent in 2018 over sales in 2017. Price knows the science is depressing. “But,” she says, “it’s not on the science side where the good things are happening. It’s on the mitigation, on the solutions.”

Ways to help kids cope with — and help combat — climate change by Ronit Feinglass Plank, Lifestyles, Washington Post, Jan 22, 2019 

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SkS in the News...

[To be added.] 

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Coming Soon on SkS...

[To be added.] 

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Climate Feedback Reviews...

How credible were 2018’s most popular climate articles?

Summary

To investigate whether last year’s most “viral” climate change stories misled the people who read them, we asked scientists to evaluate a list of top articles (as we did last year). In November, we searched Buzzsumo for the climate articles[1] with the most shares and interactions—as many as 1.2 million in the top spot—selecting the top 10 that focused on verifiable statements about climate science. (One more story entered the list in December.) Two stories did not receive any reviews, but all the evaluations and comments we collected can be found below.

Compared to last year’s top 10, there is a notable lack of low credibility stories. Two stories garnered mixed reviews from scientists. In one case, this was an article detailing false claims about sea level rise made by politicians, in which some reviewers felt the article simply wasn’t clear enough in its corrections. But there were no articles from partisan outlets presenting inaccurate rejections of climate system at the top in 2018. Instead, the list was dominated by major news outlets—with the exception of the top story, which was published by the local FOX station in St. Louis.

This leads to an interesting question we unfortunately cannot answer at this stage: is this improvement in the credibility of the most-shared articles the result of recent changes to social media algorithms or just chance?

Almost half of the stories in this list cover major IPCC and US National Climate Assessment reports released last year. It also seems clear that people are interested in learning about (or commenting on) the environmental impacts of diet. The #4 story of 2017 was about the greenhouse gas emissions associated with beef production, and two of 2018’s top stories are on the same topic.

Several of the remaining stories featured dramatic headlines on events related to climate trends—things like winter warm spells at the North Pole or the 400th consecutive month warmer than the 20th century average. The most popular story (titled “NASA releases time-lapse of the disappearing Arctic polar ice cap”) was actually an article on the 2017 global surface temperature ranking that included a NASA animation of Arctic sea ice changes over the years.

 

 

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SkS Week in Review...  

• 2019 SkS Weekly Climate Change & Global Warming News Roundup #4 by John Hartz
• New research, January 14-20, 2019 by Ari Jokimäki
• SkS Analogy 17 - Lotteries, evaporation, and superstorms by Evan & jg
• State of the climate: How the world warmed in 2018 by Zeke Hausfather, (Carbon Brief)
• 2019 SkS Weekly Climate Change & Global Warming Digest #3  by John Hartz

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Poster of the Week...

 

from Skeptical Science http://bit.ly/2TibJKO

More globular star clusters found at Milky Way’s heart

View larger at EarthSky Community Photos. | Fernando Roquel Torres in Caguas, Puerto Rico, captured this beautiful image of one of the best-known globular clusters, M13. The globulars are large, symmetrical clusters mostly found in a “halo” that extends above and below the flat disk of the galaxy, centered on the galaxy’s center. Now astronomers are beginning to find these clusters closer to the Milky Way’s heart, in what’s called the “bulge” of the galaxy. Read more about this photo.

Astronomer Denilso Camargo in Brazil emailed EarthSky last week with word of a newly published study, on the discovery of three more ancient globular clusters in the bulge – what they are calling the heart – of our home galaxy, the Milky Way. The discovery follows a similar one from 2018 by Camargo, in which he announced five globular star clusters at the heart of the Milky Way.

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

The discovery is unusual because we don’t think of globular clusters as residing near the Milky Way’s center. Instead, we think of these ancient clusters – which are thought to contain some of our galaxy’s oldest stars – as belonging to the halo of the galaxy, a more or less spherical region surrounding the galaxy’s center.

Camargo and his co-author – astronomer Dante Minniti in Chile – communicated their discovery a new paper published January 21, 2019, by the Monthly Notices of the Royal Astronomical Society Letters. Camargo wrote:

The new findings add entries to my star cluster catalog and thus they are called Camargo 1107, 1108, and 1109 (in total, the catalog has 1109 clusters discovered).

The two astronomers examined photometric data gathered by NASA’s Wide-field Infrared Survey Explorer (WISE) satellite, as well as data from the Two Micron All-Sky Survey (2MASS). Plus they used data from the European Southern Observatory’s (ESO) VISTA Variables in the Via Lactea extended survey (VVVX) and from the European Space Agency’s Gaia satellite — particularly its amazing second data release, made available last April.

The globular cluster Omega Centauri. It might contain as many as 10 million stars. Image via ESO’s La Silla Observatory/Wikimedia Commons.

Camargo wrote to EarthSky:

As relics of star formation in the early universe, globular clusters may provide important clues on the Milky Way history.

For instance, the bulge formation and evolution remains poorly understood and globular clusters are powerful tools to trace its structure, kinematics, and stellar content. The bulge has been the subject of an active debate in the last few years, which generated an important effort in order to characterize properly the central region of our home galaxy. The near- and mid-IR photometry provided by wide-field sky surveys is boosting our knowledge on this issue, since the bulge direction is heavily obscured by dust and stellar crowding in the visible wavelengths.

In this way, accurate ages and metallicities are need to reconstruct the bulge’s history from its formation to the present day.

Globular star clusters are known to be located mostly in the halo of the Milky Way, far from the galaxy’s center.

Spiral galaxies like our Milky Way contain stars, gas and dust, all organized into a flat disk containing the spiral arms, plus a more rounded bulge and halo. The famous astronomer Edwin Hubble introduced the word bulge in the early 1940s, and it’s amazing, when you think of it, that astronomers began to recognize the basic features of our home galaxy – looking from inside it – that long ago.

Today’s astronomers classify the bulges of galaxies as classical bulges and pseudobulges or disk-like bulges. Camargo explained:

Classical bulges are thought to emerge from violent events such as galaxy mergers or sinking of giant gas clumps and host older stellar population within a spherical structure like elliptical galaxies. Flattened disk-like bulges may arise on longer timescales via internal processes such as disk instabilities and secular evolution.

The stars in globular clusters are thought to be the oldest stars in the galaxy. They are what astronomers call metal-poor; that is, they’re made primarily of the original ingredients of our universe, hydrogen and helium, without the heavier elements (which astronomers inexplicably describe as metals) made in subsequent generations of stars. Camargo said that, since globular clusters:

… basically witnessed the entire history of our galaxy, they may allow us to reconstitute the chain of physical processes experienced by the Milky Way from its origin to the present-day. However, the census of globular clusters in the Milky Way is still far from complete, especially for the bulge globular clusters …

The newly discovered globular clusters are very old and extremely metal-poor, for their location, with ages in the range of 12.0 to 13.5 billion years ago.

The globular clusters discovered in this study, just as those in the previous paper, suggest that the Milky Way central region hosts a subpopulation of very old and metal-poor globular clusters, which is consistent with being an inner halo component.

Alternatively, these clusters may be part of an old classical bulge built up by merging in the early Milky Way history.

The merger scenario, by the way – the idea that our Milky Way merged with another galaxy early in its history – has been borne out by data from Gaia’s second data release.

The globular star cluster 47 Tucanae, via Fred Espenak at AstroPixels.com. Used with permission.

Bottom line: Astronomer Denilso Camargo reports on the discovery and implications of three new globular clusters, found at the heart of the Milky Way.

Source: Three candidate globular clusters discovered in the Galactic bulge

Via Denilso Camargo (email)

from EarthSky http://bit.ly/2B637j8

View larger at EarthSky Community Photos. | Fernando Roquel Torres in Caguas, Puerto Rico, captured this beautiful image of one of the best-known globular clusters, M13. The globulars are large, symmetrical clusters mostly found in a “halo” that extends above and below the flat disk of the galaxy, centered on the galaxy’s center. Now astronomers are beginning to find these clusters closer to the Milky Way’s heart, in what’s called the “bulge” of the galaxy. Read more about this photo.

Astronomer Denilso Camargo in Brazil emailed EarthSky last week with word of a newly published study, on the discovery of three more ancient globular clusters in the bulge – what they are calling the heart – of our home galaxy, the Milky Way. The discovery follows a similar one from 2018 by Camargo, in which he announced five globular star clusters at the heart of the Milky Way.

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

The discovery is unusual because we don’t think of globular clusters as residing near the Milky Way’s center. Instead, we think of these ancient clusters – which are thought to contain some of our galaxy’s oldest stars – as belonging to the halo of the galaxy, a more or less spherical region surrounding the galaxy’s center.

Camargo and his co-author – astronomer Dante Minniti in Chile – communicated their discovery a new paper published January 21, 2019, by the Monthly Notices of the Royal Astronomical Society Letters. Camargo wrote:

The new findings add entries to my star cluster catalog and thus they are called Camargo 1107, 1108, and 1109 (in total, the catalog has 1109 clusters discovered).

The two astronomers examined photometric data gathered by NASA’s Wide-field Infrared Survey Explorer (WISE) satellite, as well as data from the Two Micron All-Sky Survey (2MASS). Plus they used data from the European Southern Observatory’s (ESO) VISTA Variables in the Via Lactea extended survey (VVVX) and from the European Space Agency’s Gaia satellite — particularly its amazing second data release, made available last April.

The globular cluster Omega Centauri. It might contain as many as 10 million stars. Image via ESO’s La Silla Observatory/Wikimedia Commons.

Camargo wrote to EarthSky:

As relics of star formation in the early universe, globular clusters may provide important clues on the Milky Way history.

For instance, the bulge formation and evolution remains poorly understood and globular clusters are powerful tools to trace its structure, kinematics, and stellar content. The bulge has been the subject of an active debate in the last few years, which generated an important effort in order to characterize properly the central region of our home galaxy. The near- and mid-IR photometry provided by wide-field sky surveys is boosting our knowledge on this issue, since the bulge direction is heavily obscured by dust and stellar crowding in the visible wavelengths.

In this way, accurate ages and metallicities are need to reconstruct the bulge’s history from its formation to the present day.

Globular star clusters are known to be located mostly in the halo of the Milky Way, far from the galaxy’s center.

Spiral galaxies like our Milky Way contain stars, gas and dust, all organized into a flat disk containing the spiral arms, plus a more rounded bulge and halo. The famous astronomer Edwin Hubble introduced the word bulge in the early 1940s, and it’s amazing, when you think of it, that astronomers began to recognize the basic features of our home galaxy – looking from inside it – that long ago.

Today’s astronomers classify the bulges of galaxies as classical bulges and pseudobulges or disk-like bulges. Camargo explained:

Classical bulges are thought to emerge from violent events such as galaxy mergers or sinking of giant gas clumps and host older stellar population within a spherical structure like elliptical galaxies. Flattened disk-like bulges may arise on longer timescales via internal processes such as disk instabilities and secular evolution.

The stars in globular clusters are thought to be the oldest stars in the galaxy. They are what astronomers call metal-poor; that is, they’re made primarily of the original ingredients of our universe, hydrogen and helium, without the heavier elements (which astronomers inexplicably describe as metals) made in subsequent generations of stars. Camargo said that, since globular clusters:

… basically witnessed the entire history of our galaxy, they may allow us to reconstitute the chain of physical processes experienced by the Milky Way from its origin to the present-day. However, the census of globular clusters in the Milky Way is still far from complete, especially for the bulge globular clusters …

The newly discovered globular clusters are very old and extremely metal-poor, for their location, with ages in the range of 12.0 to 13.5 billion years ago.

The globular clusters discovered in this study, just as those in the previous paper, suggest that the Milky Way central region hosts a subpopulation of very old and metal-poor globular clusters, which is consistent with being an inner halo component.

Alternatively, these clusters may be part of an old classical bulge built up by merging in the early Milky Way history.

The merger scenario, by the way – the idea that our Milky Way merged with another galaxy early in its history – has been borne out by data from Gaia’s second data release.

The globular star cluster 47 Tucanae, via Fred Espenak at AstroPixels.com. Used with permission.

Bottom line: Astronomer Denilso Camargo reports on the discovery and implications of three new globular clusters, found at the heart of the Milky Way.

Source: Three candidate globular clusters discovered in the Galactic bulge

Via Denilso Camargo (email)

from EarthSky http://bit.ly/2B637j8

The moon at mid-arch from full to new

View larger. | The last quarter moon of January 27 will be about as high north of the ecliptic as it can get. You can see why, in this detail from Guy Ottewell’s Zodiac Wavy Chart for 2019.

Originally published at Guy Ottewell’s blog. Reprinted here with permission.

The blue line is the ecliptic, curved in this projection in which the celestial equator – the red line – is straight.

On January 21, 2019 ascending node through the ecliptic coincided with full moon, so there was a total lunar eclipse. Descending node on February 3 will come close to new moon – though not as close as on January 6, when there was a partial solar eclipse.

Halfway between, at last quarter on January 27, the moon is at the top of its arch, about 5° (its orbital inclination) north of the ecliptic.

A result of this is that the libration is at a maximum for the year. This is interesting though, as we’ll explain, of limited observational advantage.

Libration is the moon’s apparent “rocking,” caused by its slightly inclined and elliptical orbit. It’s indicated in our chart by a red tab on the moon’s limb (edge). The tab is at the part of the limb where libration allows us to see farthest into the moon’s usually invisible far side. The libration maximum is at January 27, 17:00 UTC, about 3 hours before the last quarter instant, and the amount of libration is a little over 10°.

The libration point has to be on the part of the moon toward the ecliptic; from the ecliptic plane we are now looking slightly northward toward the moon, so we see more at its southern limb.

Unfortunately the point is on the un-sunlit half of the last quarter moon. So we can’t see past that part of the limb into luna incognita, the “unknown omon.” But it’s not far from the moon’s south pole. Therefore, a little to the left, where the sunlit half begins, it might be possible to see a little way into the mostly hidden South-Pole-Aitken Basin, where China’s Chang’e 4 lander is now exploring.

The libration continues approximately the same for several days, as the tabs show.

To see a last quarter moon, you have to be looking after it rises around midnight. Better to be later than that, in the pre-dawn hours. The moon is then higher, and risen behind it are the stars and planets it is going to pass in the next few dawns – Antares, Jupiter, Venus, Saturn.

View larger. | Monday morning’s moon is just past last quarter, rising around midnight, looking like half a pie. This week, as the moon continues to wane, it will pass the planets in the early morning sky. Read more.

As I was writing this, at about six this morning, I opened the window shutters beside me and saw in a black gap between roofs a light so brilliant that I almost thought the town cinema was on fire again.

It was the moon, a day before last quarter.

Bottom line: Last quarter moon is January 27, 2019 at 21:12 UTC; translate UTC to your time.

from EarthSky http://bit.ly/2MACJ5z

View larger. | The last quarter moon of January 27 will be about as high north of the ecliptic as it can get. You can see why, in this detail from Guy Ottewell’s Zodiac Wavy Chart for 2019.

Originally published at Guy Ottewell’s blog. Reprinted here with permission.

The blue line is the ecliptic, curved in this projection in which the celestial equator – the red line – is straight.

On January 21, 2019 ascending node through the ecliptic coincided with full moon, so there was a total lunar eclipse. Descending node on February 3 will come close to new moon – though not as close as on January 6, when there was a partial solar eclipse.

Halfway between, at last quarter on January 27, the moon is at the top of its arch, about 5° (its orbital inclination) north of the ecliptic.

A result of this is that the libration is at a maximum for the year. This is interesting though, as we’ll explain, of limited observational advantage.

Libration is the moon’s apparent “rocking,” caused by its slightly inclined and elliptical orbit. It’s indicated in our chart by a red tab on the moon’s limb (edge). The tab is at the part of the limb where libration allows us to see farthest into the moon’s usually invisible far side. The libration maximum is at January 27, 17:00 UTC, about 3 hours before the last quarter instant, and the amount of libration is a little over 10°.

The libration point has to be on the part of the moon toward the ecliptic; from the ecliptic plane we are now looking slightly northward toward the moon, so we see more at its southern limb.

Unfortunately the point is on the un-sunlit half of the last quarter moon. So we can’t see past that part of the limb into luna incognita, the “unknown omon.” But it’s not far from the moon’s south pole. Therefore, a little to the left, where the sunlit half begins, it might be possible to see a little way into the mostly hidden South-Pole-Aitken Basin, where China’s Chang’e 4 lander is now exploring.

The libration continues approximately the same for several days, as the tabs show.

To see a last quarter moon, you have to be looking after it rises around midnight. Better to be later than that, in the pre-dawn hours. The moon is then higher, and risen behind it are the stars and planets it is going to pass in the next few dawns – Antares, Jupiter, Venus, Saturn.

View larger. | Monday morning’s moon is just past last quarter, rising around midnight, looking like half a pie. This week, as the moon continues to wane, it will pass the planets in the early morning sky. Read more.

As I was writing this, at about six this morning, I opened the window shutters beside me and saw in a black gap between roofs a light so brilliant that I almost thought the town cinema was on fire again.

It was the moon, a day before last quarter.

Bottom line: Last quarter moon is January 27, 2019 at 21:12 UTC; translate UTC to your time.

from EarthSky http://bit.ly/2MACJ5z

Orion the Hunter is easy to spot

Tonight – or any winter evening – look for the constellation Orion the Hunter. It’s probably the easiest to pick out of all the constellations in the Northern Hemisphere winter sky (Southern Hemisphere summer sky). It’s identifiable by Orion’s Belt, three medium-bright stars in a short, straight row at the mid-section of the Hunter. See these stars? They are easy to spot on the sky’s dome. As seen from mid-northern latitudes, you’ll find Orion in the southeast at early evening and shining high in the south by mid-evening (around 9 p.m. local time). If you live at temperate latitudes to the south of the equator, you’ll see Orion high in your northern sky at this hour. Pick out Orion’s Belt and the nearby bright stars in that part of the sky, and you’ve probably found Orion.

Donate: Your support means the world to us

There’s plenty to see in Orion, too, and it’s easy to find.

Stars in distinct constellations like Orion look connected, perhaps even gravitationally bound, but usually they aren’t. Certainly Orion’s stars aren’t bound to each other by anything but their general location near one another along a single line of sight from Earth. The stars of Orion just happen to make an easy visual pattern on our sky’s dome.

Meanwhile, the stars in Orion and most other constellations are located at vastly different distances from each other. For example, notice the two brightest stars in Orion, Betelgeuse and Rigel. Betelgeuse is estimated to be located 522 light-years away, while Rigel’s distance is 773 light-years.

On the other hand, those prominent stars in Orion’s Belt are somewhat related. They are all giant stars in a nearby spiral arm of our Milky Way galaxy. These stars’ names are Mintaka, Alnilam, and Alnitak.

Bottom line: At this time of year, the constellation Orion the Hunter takes center stage in the star-studded sky! It’s identifiable by Orion’s Belt, three medium-bright stars in a short, straight row at the mid-section of the Hunter.

Why do stars seem brighter in winter?

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

from EarthSky http://bit.ly/2Wp0Fh5

Tonight – or any winter evening – look for the constellation Orion the Hunter. It’s probably the easiest to pick out of all the constellations in the Northern Hemisphere winter sky (Southern Hemisphere summer sky). It’s identifiable by Orion’s Belt, three medium-bright stars in a short, straight row at the mid-section of the Hunter. See these stars? They are easy to spot on the sky’s dome. As seen from mid-northern latitudes, you’ll find Orion in the southeast at early evening and shining high in the south by mid-evening (around 9 p.m. local time). If you live at temperate latitudes to the south of the equator, you’ll see Orion high in your northern sky at this hour. Pick out Orion’s Belt and the nearby bright stars in that part of the sky, and you’ve probably found Orion.

Donate: Your support means the world to us

There’s plenty to see in Orion, too, and it’s easy to find.

Stars in distinct constellations like Orion look connected, perhaps even gravitationally bound, but usually they aren’t. Certainly Orion’s stars aren’t bound to each other by anything but their general location near one another along a single line of sight from Earth. The stars of Orion just happen to make an easy visual pattern on our sky’s dome.

Meanwhile, the stars in Orion and most other constellations are located at vastly different distances from each other. For example, notice the two brightest stars in Orion, Betelgeuse and Rigel. Betelgeuse is estimated to be located 522 light-years away, while Rigel’s distance is 773 light-years.

On the other hand, those prominent stars in Orion’s Belt are somewhat related. They are all giant stars in a nearby spiral arm of our Milky Way galaxy. These stars’ names are Mintaka, Alnilam, and Alnitak.

Bottom line: At this time of year, the constellation Orion the Hunter takes center stage in the star-studded sky! It’s identifiable by Orion’s Belt, three medium-bright stars in a short, straight row at the mid-section of the Hunter.

Why do stars seem brighter in winter?

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

from EarthSky http://bit.ly/2Wp0Fh5