A bold new theory of intelligent life and origin of humanity

View larger. | A new theory proposes that humanity – and other analogous forms of intelligent life in the universe – might not be as extraordinary or improbable as previously thought. Instead, we might represent the probable outcome of biological and planetary evolution. The new theory challenges the decades-old hard steps” theory of human evolution. Image via Igor Cibulsky/ Pexels.

• Is humanity the extraordinary result of improbable events? If so, does it mean that other intelligent life in the universe might be rare?
• Humanity might be the natural probable outcome of evolution on Earth, new research suggests. This challenges the existing theory that human life was simply a matter of luck.
• This also increases the probability of intelligent life elsewhere in the universe.

The ‘hard steps’ theory of human evolution and intelligent life

Was the evolution of humanity a fluke? Previous studies have suggested the human species was the result of a series of improbable events, making us a unique and rare product of planetary evolution. But now scientists in the U.S. and Germany have proposed a new model for the origin of humanity. They said on February 14, 2025, that the long-accepted “hard steps” theory might be inaccurate. Instead of improbable, humanity might be the natural evolutionary outcome on Earth. If so, this has bold implications for the evolution of analogous intelligent life on other planets in the universe as well.

The researchers published their peer-reviewed findings in Science Advances on February 14.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Is humanity extraordinary?

Scientists have long thought humanity is the result of a series of improbable events over billions of years of evolution. Indeed, our overall intelligence, sciences, arts, technological achievements, etc. set us apart from the rest of the animal kingdom.

The “hard steps” theory says that humanity evolved the way it did due to many unlikely events. This makes us extraordinary. But is that the real story? The new study doesn’t dispute the fact that humanity evolved over millions of years. But it challenges the idea that humanity is overtly unique.

Physicist Brandon Carter developed the “hard-steps” theory in 1983. It stated that due to how long it took humans to evolve – relative to the age of the sun – the chances of human-like intelligent lifeforms arising on other planets were low.

Evolution of humanity and intelligent life not so improbable after all?

The researchers state that humanity might be the natural evolutionary outcome for Earth. And that evolutionary processes might be similar on other planets where intelligent life evolves. Daniel Brady Mills is the lead author of the paper, at The University of Munich in Germany. He said:

We’re arguing that intelligent life may not require a series of lucky breaks to exist. Humans didn’t evolve ‘early’ or ‘late’ in Earth’s history, but ‘on time,’ when the conditions were in place. Perhaps it’s only a matter of time, and maybe other planets are able to achieve these conditions more rapidly than Earth did, while other planets might take even longer.

Luck and chance might not have had as much to do with human evolution as first thought. Co-author Jennifer Macalady at Penn State said:

This is a significant shift in how we think about the history of life. It suggests that the evolution of complex life may be less about luck and more about the interplay between life and its environment, opening up exciting new avenues of research in our quest to understand our origins and our place in the universe.

The "hard-steps" model argues that human-like life was unlikely to evolve on Earth and is vanishingly rare in the Universe. Here, in our new Science Advances article, we challenge its foundational logic: https://ift.tt/Nadxurh…

— Daniel Brady Mills (@danbmills.bsky.social) 2025-02-14T19:28:43.735Z

A permissive global environment

The new study theorizes that the evolution of humans became possible when the global environment reached a permissive state. Complex lifeforms like humans require oxygen. So when photosynthesizing microbes and bacteria created enough oxygen in the atmosphere, conditions were suitable for more complex life to evolve. In other words, it was simply a natural progression instead of a fluke.

This is part of what the researchers call windows of opportunity. Other factors included nutrient availability, sea surface temperature and ocean salinity. The researchers realized that Earth became suitable for complex life such as humans only recently in its overall history. Again, just a natural progression of events.

Evolving intelligent life took billions of years ? but it may not have been as unlikely as many scientists predictedtheconversation.com/evolving-int…

— Jenn Macalady (@jmacalad.bsky.social) 2025-02-16T01:59:09.805Z

Earth’s geological timescale as a tool

The study basically reverses the basis of the old “hard steps” theory. It uses the geological timescale of the Earth instead of the lifespan of the sun. As co-author Jason Wright at Penn State explained:

We’re taking the view that rather than base our predictions on the lifespan of the sun, we should use a geological time scale, because that’s how long it takes for the atmosphere and landscape to change. These are normal timescales on the Earth. If life evolves with the planet, then it will evolve on a planetary time scale at a planetary pace.

This new perspective suggests that the emergence of intelligent life might not be such a long-shot after all. Instead of a series of improbable events, evolution may be more of a predictable process, unfolding as global conditions allow. Our framework applies not only to Earth, but also other planets, increasing the possibility that life similar to ours could exist elsewhere.

A multi-disciplinary approach

One of the big strengths of the new theory is that it is a collaboration of various scientific disciplines. The “hard-steps” model was based in astrophysics. But the new paper takes a different approach. Both physicists and geobiologists are involved. Macalady said:

This paper is the most generous act of interdisciplinary work. Our fields were far apart, and we put them on the same page to get at this question of how we got here and are we alone? There was a gulf, and we built a bridge.

You can also read good overview of the new theory by Mills, Wright and Macalady in The Conversation (February 14, 2025).

Bottom line: Was the rise of humanity simply a matter of luck? A new theory says no, that we – and perhaps other intelligent life – are the probable outcome of evolution.

Source: A reassessment of the “hard-steps” model for the evolution of intelligent life

Via Penn State

Read more: Estimating the odds for intelligent life in the multiverse

Read more: Alien technology might signal extraterrestrial life

The post A bold new theory of intelligent life and origin of humanity first appeared on EarthSky.

from EarthSky https://ift.tt/GE4hqXi

View larger. | A new theory proposes that humanity – and other analogous forms of intelligent life in the universe – might not be as extraordinary or improbable as previously thought. Instead, we might represent the probable outcome of biological and planetary evolution. The new theory challenges the decades-old hard steps” theory of human evolution. Image via Igor Cibulsky/ Pexels.

• Is humanity the extraordinary result of improbable events? If so, does it mean that other intelligent life in the universe might be rare?
• Humanity might be the natural probable outcome of evolution on Earth, new research suggests. This challenges the existing theory that human life was simply a matter of luck.
• This also increases the probability of intelligent life elsewhere in the universe.

The ‘hard steps’ theory of human evolution and intelligent life

Was the evolution of humanity a fluke? Previous studies have suggested the human species was the result of a series of improbable events, making us a unique and rare product of planetary evolution. But now scientists in the U.S. and Germany have proposed a new model for the origin of humanity. They said on February 14, 2025, that the long-accepted “hard steps” theory might be inaccurate. Instead of improbable, humanity might be the natural evolutionary outcome on Earth. If so, this has bold implications for the evolution of analogous intelligent life on other planets in the universe as well.

The researchers published their peer-reviewed findings in Science Advances on February 14.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

Is humanity extraordinary?

Scientists have long thought humanity is the result of a series of improbable events over billions of years of evolution. Indeed, our overall intelligence, sciences, arts, technological achievements, etc. set us apart from the rest of the animal kingdom.

The “hard steps” theory says that humanity evolved the way it did due to many unlikely events. This makes us extraordinary. But is that the real story? The new study doesn’t dispute the fact that humanity evolved over millions of years. But it challenges the idea that humanity is overtly unique.

Physicist Brandon Carter developed the “hard-steps” theory in 1983. It stated that due to how long it took humans to evolve – relative to the age of the sun – the chances of human-like intelligent lifeforms arising on other planets were low.

Evolution of humanity and intelligent life not so improbable after all?

The researchers state that humanity might be the natural evolutionary outcome for Earth. And that evolutionary processes might be similar on other planets where intelligent life evolves. Daniel Brady Mills is the lead author of the paper, at The University of Munich in Germany. He said:

We’re arguing that intelligent life may not require a series of lucky breaks to exist. Humans didn’t evolve ‘early’ or ‘late’ in Earth’s history, but ‘on time,’ when the conditions were in place. Perhaps it’s only a matter of time, and maybe other planets are able to achieve these conditions more rapidly than Earth did, while other planets might take even longer.

Luck and chance might not have had as much to do with human evolution as first thought. Co-author Jennifer Macalady at Penn State said:

This is a significant shift in how we think about the history of life. It suggests that the evolution of complex life may be less about luck and more about the interplay between life and its environment, opening up exciting new avenues of research in our quest to understand our origins and our place in the universe.

The "hard-steps" model argues that human-like life was unlikely to evolve on Earth and is vanishingly rare in the Universe. Here, in our new Science Advances article, we challenge its foundational logic: https://ift.tt/Nadxurh…

— Daniel Brady Mills (@danbmills.bsky.social) 2025-02-14T19:28:43.735Z

A permissive global environment

The new study theorizes that the evolution of humans became possible when the global environment reached a permissive state. Complex lifeforms like humans require oxygen. So when photosynthesizing microbes and bacteria created enough oxygen in the atmosphere, conditions were suitable for more complex life to evolve. In other words, it was simply a natural progression instead of a fluke.

This is part of what the researchers call windows of opportunity. Other factors included nutrient availability, sea surface temperature and ocean salinity. The researchers realized that Earth became suitable for complex life such as humans only recently in its overall history. Again, just a natural progression of events.

Evolving intelligent life took billions of years ? but it may not have been as unlikely as many scientists predictedtheconversation.com/evolving-int…

— Jenn Macalady (@jmacalad.bsky.social) 2025-02-16T01:59:09.805Z

Earth’s geological timescale as a tool

The study basically reverses the basis of the old “hard steps” theory. It uses the geological timescale of the Earth instead of the lifespan of the sun. As co-author Jason Wright at Penn State explained:

We’re taking the view that rather than base our predictions on the lifespan of the sun, we should use a geological time scale, because that’s how long it takes for the atmosphere and landscape to change. These are normal timescales on the Earth. If life evolves with the planet, then it will evolve on a planetary time scale at a planetary pace.

This new perspective suggests that the emergence of intelligent life might not be such a long-shot after all. Instead of a series of improbable events, evolution may be more of a predictable process, unfolding as global conditions allow. Our framework applies not only to Earth, but also other planets, increasing the possibility that life similar to ours could exist elsewhere.

A multi-disciplinary approach

One of the big strengths of the new theory is that it is a collaboration of various scientific disciplines. The “hard-steps” model was based in astrophysics. But the new paper takes a different approach. Both physicists and geobiologists are involved. Macalady said:

This paper is the most generous act of interdisciplinary work. Our fields were far apart, and we put them on the same page to get at this question of how we got here and are we alone? There was a gulf, and we built a bridge.

You can also read good overview of the new theory by Mills, Wright and Macalady in The Conversation (February 14, 2025).

Bottom line: Was the rise of humanity simply a matter of luck? A new theory says no, that we – and perhaps other intelligent life – are the probable outcome of evolution.

Source: A reassessment of the “hard-steps” model for the evolution of intelligent life

Via Penn State

Read more: Estimating the odds for intelligent life in the multiverse

Read more: Alien technology might signal extraterrestrial life

The post A bold new theory of intelligent life and origin of humanity first appeared on EarthSky.

from EarthSky https://ift.tt/GE4hqXi

Thousands of new black holes just found!

Using the Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak in Arizona, astronomers have discovered thousands of new black holes. These discoveries have more than tripled the amount of known intermediate-mass black holes and active black holes at the centers of dwarf galaxies. Images and videos: NOIRLab/NSF/AURA/J. da Silva/Legacy Surveys/D. Lang (Perimeter Institute)/NAOJ/HSC Collaboration/D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab)/R. Proctor (NSF NOIRLab)/R.T. Sparks/ESO/M. Kornmesser/N. Bartmann (NSF NOIRLab) Music: Stellardrone – Airglow.

Thousands of new black holes

The number of black holes we know of in space has just ballooned. On February 19, 2025, NOIRLab said its astronomers have discovered thousands of new black holes. The number includes 300 intermediate-mass black hole candidates (weighing in at weighs between 100 and 100,000 times the mass of the sun). Plus, it includes some 2,500 candidate dwarf galaxies with black holes that are actively feeding at their centers.

These discoveries more than triple the census of black holes in both categories.

The mission of the Dark Energy Spectroscopic Instrument (DESI) on the 4-meter Mayall Telescope at the NSF Kitt Peak National Observatory in Arizona is to survey millions of galaxies. It can capture the light of 5,000 galaxies at once! The researchers used DESI to find the new black hole candidates inside distant galaxies. And the discoveries came from just a fraction of the data that the five-year survey will produce. The researchers used only data from the survey validation and 20% from the first year of operations.

Co-author Rahma Alfarsy of the University of Portsmouth said:

Having witnessed the development and outcomes of this brilliant work, we are really excited to see what else will be unearthed from DESI’s treasure trove of extra-galactic observations.

The researchers published their peer-reviewed results in The Astrophysical Journal on February 19, 2025. A copy is available on arXiv.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

This artist’s concept shows a dwarf galaxy with a bright, active nucleus thanks to a feeding black hole. The background contains more dwarf galaxies and other galaxies that are also home to black holes. Image via NOIRLab/ NSF/ AURA/ J. da Silva/ M. Zamani.

Surveying a slew of galaxies

The team – led by University of Utah postdoctoral researcher Ragadeepika Pucha – looked at the spectra of 410,000 galaxies. About a quarter of those were dwarf galaxies.

Astronomers already know that a monster black hole lies at the center of the Milky Way galaxy. And they think similar black holes lie at the centers of other large galaxies. But the smaller the galaxy, the murkier the picture. When looking at dim, distant dwarf galaxies, the best bet at finding a black hole is to look for an active galactic nucleus. That signals that a black hole is feeding on stars at its core.

Pucha said:

When a black hole at the center of a galaxy starts feeding, it unleashes a tremendous amount of energy into its surroundings, transforming into what we call an active galactic nucleus. This dramatic activity serves as a beacon, allowing us to identify hidden black holes in these small galaxies.

Here are some of the candidate dwarf galaxies with active galactic nuclei fed by black holes. These images are from the Subaru Telescope. Image via Legacy Surveys/ D. Lang (Perimeter Institute)/ NAOJ/ HSC Collaboration/ D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab).

Intermediate-mass black holes

The team also identified 300 intermediate-mass black hole candidates. This size of black hole can provide the missing link between two more common black holes. We know of many supermassive black holes lurking at the centers of galaxies. And we know of stellar-mass black holes, formed when massive stars explode as supernovae. Intermediate-mass black holes might be relics of the first black holes.

These mid-range black holes are harder to find. Unlike stellar-mass black holes, they aren’t preceded by a large supernova explosion. And unlike supermassive black holes, they don’t have a radio- and X-ray-bright glowing accretion disk.

Interestingly, astronomers thought the black holes at the centers of dwarf galaxies would be of an intermediate-mass size. But in this research, only 70 of the new candidate intermediate-mass black holes overlap with candidates of dwarf galaxies with active galactic nuclei. This raises more questions. Pucha said:

For example, is there any relationship between the mechanisms of black hole formation and the types of galaxies they inhabit? Our wealth of new candidates will help us delve deeper into these mysteries, enriching our understanding of black holes and their pivotal role in galaxy evolution.

Here are some of the galaxies hosting intermediate-mass black hole candidates. They’re arranged in order of increasing stellar mass. The Subaru Telescope captured these images. Image via Legacy Surveys/ D. Lang (Perimeter Institute)/ NAOJ/ HSC Collaboration/ D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab).

Bottom line: Scientists have discovered thousands of new black holes, more than tripling the number we knew before. How’d they do it? Read more here.

Source: Tripling the Census of Dwarf AGN Candidates Using DESI Early Data

Via NOIRLab

Via University of Portsmouth

The post Thousands of new black holes just found! first appeared on EarthSky.

from EarthSky https://ift.tt/B29txpa

Using the Dark Energy Spectroscopic Instrument (DESI) at Kitt Peak in Arizona, astronomers have discovered thousands of new black holes. These discoveries have more than tripled the amount of known intermediate-mass black holes and active black holes at the centers of dwarf galaxies. Images and videos: NOIRLab/NSF/AURA/J. da Silva/Legacy Surveys/D. Lang (Perimeter Institute)/NAOJ/HSC Collaboration/D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab)/R. Proctor (NSF NOIRLab)/R.T. Sparks/ESO/M. Kornmesser/N. Bartmann (NSF NOIRLab) Music: Stellardrone – Airglow.

Thousands of new black holes

The number of black holes we know of in space has just ballooned. On February 19, 2025, NOIRLab said its astronomers have discovered thousands of new black holes. The number includes 300 intermediate-mass black hole candidates (weighing in at weighs between 100 and 100,000 times the mass of the sun). Plus, it includes some 2,500 candidate dwarf galaxies with black holes that are actively feeding at their centers.

These discoveries more than triple the census of black holes in both categories.

The mission of the Dark Energy Spectroscopic Instrument (DESI) on the 4-meter Mayall Telescope at the NSF Kitt Peak National Observatory in Arizona is to survey millions of galaxies. It can capture the light of 5,000 galaxies at once! The researchers used DESI to find the new black hole candidates inside distant galaxies. And the discoveries came from just a fraction of the data that the five-year survey will produce. The researchers used only data from the survey validation and 20% from the first year of operations.

Co-author Rahma Alfarsy of the University of Portsmouth said:

Having witnessed the development and outcomes of this brilliant work, we are really excited to see what else will be unearthed from DESI’s treasure trove of extra-galactic observations.

The researchers published their peer-reviewed results in The Astrophysical Journal on February 19, 2025. A copy is available on arXiv.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

This artist’s concept shows a dwarf galaxy with a bright, active nucleus thanks to a feeding black hole. The background contains more dwarf galaxies and other galaxies that are also home to black holes. Image via NOIRLab/ NSF/ AURA/ J. da Silva/ M. Zamani.

Surveying a slew of galaxies

The team – led by University of Utah postdoctoral researcher Ragadeepika Pucha – looked at the spectra of 410,000 galaxies. About a quarter of those were dwarf galaxies.

Astronomers already know that a monster black hole lies at the center of the Milky Way galaxy. And they think similar black holes lie at the centers of other large galaxies. But the smaller the galaxy, the murkier the picture. When looking at dim, distant dwarf galaxies, the best bet at finding a black hole is to look for an active galactic nucleus. That signals that a black hole is feeding on stars at its core.

Pucha said:

When a black hole at the center of a galaxy starts feeding, it unleashes a tremendous amount of energy into its surroundings, transforming into what we call an active galactic nucleus. This dramatic activity serves as a beacon, allowing us to identify hidden black holes in these small galaxies.

Here are some of the candidate dwarf galaxies with active galactic nuclei fed by black holes. These images are from the Subaru Telescope. Image via Legacy Surveys/ D. Lang (Perimeter Institute)/ NAOJ/ HSC Collaboration/ D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab).

Intermediate-mass black holes

The team also identified 300 intermediate-mass black hole candidates. This size of black hole can provide the missing link between two more common black holes. We know of many supermassive black holes lurking at the centers of galaxies. And we know of stellar-mass black holes, formed when massive stars explode as supernovae. Intermediate-mass black holes might be relics of the first black holes.

These mid-range black holes are harder to find. Unlike stellar-mass black holes, they aren’t preceded by a large supernova explosion. And unlike supermassive black holes, they don’t have a radio- and X-ray-bright glowing accretion disk.

Interestingly, astronomers thought the black holes at the centers of dwarf galaxies would be of an intermediate-mass size. But in this research, only 70 of the new candidate intermediate-mass black holes overlap with candidates of dwarf galaxies with active galactic nuclei. This raises more questions. Pucha said:

For example, is there any relationship between the mechanisms of black hole formation and the types of galaxies they inhabit? Our wealth of new candidates will help us delve deeper into these mysteries, enriching our understanding of black holes and their pivotal role in galaxy evolution.

Here are some of the galaxies hosting intermediate-mass black hole candidates. They’re arranged in order of increasing stellar mass. The Subaru Telescope captured these images. Image via Legacy Surveys/ D. Lang (Perimeter Institute)/ NAOJ/ HSC Collaboration/ D. de Martin (NSF NOIRLab) & M. Zamani (NSF NOIRLab).

Bottom line: Scientists have discovered thousands of new black holes, more than tripling the number we knew before. How’d they do it? Read more here.

Source: Tripling the Census of Dwarf AGN Candidates Using DESI Early Data

Via NOIRLab

Via University of Portsmouth

The post Thousands of new black holes just found! first appeared on EarthSky.

from EarthSky https://ift.tt/B29txpa

Address science misinformation by building community

The best way to address science misinformation? Build conversation and community. Image via Geralt/ Pixabay.

• Science misinformation is an area that scientists are having to address more and more.
• Sharing facts is not always the best way to combat misinformation. This is because some facts can feel threatening.
• Building community and working within your own social network can change ideas and eventually social norms.

By Anne Toomey, Pace University

How should you address science misinformation?

Misinformation about scientific topics, including falsehoods such as vaccines cause autism and climate change being an entirely natural phenomenon, is an issue scientists have been discussing more and more. Widespread misinformation can lead to confusion about public health and environmental issues and can hinder those working to solve societal problems.

As an environmental social scientist who researches how science can have an impact on society, I seek effective ways to address misinformation.

There are many approaches that can work to some extent: for example, counteracting erroneous information with statements about scientific topics based on quality research that convey that the majority of experts agree. Another approach is to inoculate people by preparing them to spot the fallacies in misinformation before they are first exposed to it.

But one of the most important ways to counteract misinformation is less about the facts and more about how those facts move within social networks and communities. In other words, it’s not enough for science to be right. It has to be accepted within people’s social circles to have any meaningful impact.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Can facts change minds?

Most people tend to assume their knowledge and ideas are based on a rational, objective analysis of information. And that’s sometimes the case. If it’s snowing outside, people don’t insist that it’s sunny and warm, no matter how much they might like it to be.

Similarly, if a person comes across some novel fact in the news, such as the discovery of a new type of plant in the Amazon, they might just absorb that information and go about their day.

But rationality and the ability to embrace new information goes out the window when it comes up against ideas that challenge one’s preexisting worldviews or social identities. Such information can feel like a personal attack, leading the body to release cortisol, a hormone associated with stress. So, certain facts can feel threatening or offensive.

Sometimes, people accept new information without much thought. But when new information challenges their existing beliefs, they may double down on their point of view.

What is my community saying?

Compounding what is happening in the brain is what’s happening in people’s communities. Humans are social animals who turn to others they trust to help them understand what’s what. People are attuned to what is considered normal or acceptable in their social environments. So if their social group holds a particular belief, they are more likely to adopt that belief too.

One’s cultural and political identities often dictate how they interpret the same information. This leads to disagreements even when presented with the same evidence.

These cultural identities explain why, for example, research finds that science-skeptical behaviors, such as vaccine hesitancy and climate denialism, tend to cluster in social and geographical pockets. In these pockets, people’s skepticism is reinforced by others with similar beliefs in their social network. In such cases, providing more evidence on a certain topic won’t help. And it may even result in people digging in their heels deeper to deny the evidence.

So if facts don’t necessarily change minds, what will?

Leveraging community networks

Recent research provides a solution for scientists and agencies hoping to correct misinformation: Rather than fighting against humans’ social nature, work with it.

When people see trusted individuals within their social networks holding a certain belief, that belief becomes more credible and easier to adopt. Leveraging those community connections can allow new ideas to gain traction.

One great example of using social networks to fight misinformation is how polio was eradicated in India. In 2009, India was the polio epicenter of the world, home to half of the world’s cases. These cases were largely clustered in vaccine-hesitant regions of the country. But by 2011, only two years later, India had only one case, and the country formally celebrated the eradication of polio in 2014.

Creating change in the face of science misinformation

How did India go from having half of the world’s cases to just one case in under two years?

Public health agencies asked volunteers from within vaccine-resistant communities to go on a listening campaign and become ambassadors for the vaccine. The volunteers were trained in interpersonal communication skills and tasked with spending time with parents. They built trust and rapport through regular visits.

Because the volunteers were known within the communities, they were able to make headway where health workers from urban areas had not. As they established rapport, hesitant parents shared their concerns, which typically went beyond polio to include other health issues.

Over time, more and more parents decided to vaccinate their children, until there was a tipping point and vaccination became a social norm. Perhaps most notably, the campaign led to full routine immunization rates in some high-risk regions of the country.

India’s incredible success emphasizes the importance of personal interactions for changing minds, which means moving beyond simply presenting the facts. Building trust, listening to concerns and engaging with communities in a meaningful way were integral to India’s eradication of polio.

Science misinformation and the power of conversations

Another example of using the power of social networks to talk about controversial science topics comes from a method called deep canvassing. Deep canvassing is a unique communication method that involves going door to door to have conversations with members of the public.

But it’s unlike traditional canvassing, which often focuses on rallying existing supporters. Deep canvassing deliberately seeks to engage with those who hold different viewpoints, focusing efforts in communities where the topic is controversial.

Canvassers are trained to ask questions to better understand the other person’s experiences and perspectives on the issue. And then they share their own personal stories. This helps to create a human connection, where both parties feel heard and respected. This connection can help to reduce the negative emotions that may emerge when someone is challenged to rethink their beliefs.

Neighbors United

One notable example of deep canvassing in action is the work of Neighbors United, an environmental nonprofit in Canada. They used a deep-canvassing approach to engage people in conversations about climate change.

They piloted the method in a rural, conservative community called Trail, home to one of the largest zinc and lead smelters in the world. Prior efforts to engage community members hadn’t had much of an effect. That’s because taking action on climate change was largely seen as being in conflict with how many people made their living.

But the deep-canvassing method worked. Going door to door, the canvassers listened to residents’ concerns, shared their own stories about the impact of climate change and highlighted local environmental successes.

As a result, 1 in 3 residents shifted their views about the importance of taking action to address climate change. This broad community support led the City Council to vote to transition to 100% renewable energy by 2050.

Working within social networks

Sociologist Anthony Giddens described interpersonal interactions between experts, such as doctors or scientists, and the public as access points. He argued that these points are vital for maintaining trust in governmental and scientific institutions, such as the Centers for Disease Control and Prevention or the Environmental Protection Agency.

These face-to-face interactions with experts can help people see them as kind, warm and professional, which can lead to trust.

These examples show that creating support for attitudes and behaviors based on science requires more than just presenting facts. It requires creating meaningful dialogue between skeptical groups and scientific messengers. It’s also a reminder that while social networks may serve to propagate misinformation, they can also be an important tool for addressing it.

Anne Toomey, Associate Professor of Environmental Studies and Science, Pace University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: If you want to help combat science misinformation, work within your community and social network to have personal conversations and share stories.

Read more: Is social media polarization about to get worse?

The post Address science misinformation by building community first appeared on EarthSky.

from EarthSky https://ift.tt/7zH9xon

The best way to address science misinformation? Build conversation and community. Image via Geralt/ Pixabay.

• Science misinformation is an area that scientists are having to address more and more.
• Sharing facts is not always the best way to combat misinformation. This is because some facts can feel threatening.
• Building community and working within your own social network can change ideas and eventually social norms.

By Anne Toomey, Pace University

How should you address science misinformation?

Misinformation about scientific topics, including falsehoods such as vaccines cause autism and climate change being an entirely natural phenomenon, is an issue scientists have been discussing more and more. Widespread misinformation can lead to confusion about public health and environmental issues and can hinder those working to solve societal problems.

As an environmental social scientist who researches how science can have an impact on society, I seek effective ways to address misinformation.

There are many approaches that can work to some extent: for example, counteracting erroneous information with statements about scientific topics based on quality research that convey that the majority of experts agree. Another approach is to inoculate people by preparing them to spot the fallacies in misinformation before they are first exposed to it.

But one of the most important ways to counteract misinformation is less about the facts and more about how those facts move within social networks and communities. In other words, it’s not enough for science to be right. It has to be accepted within people’s social circles to have any meaningful impact.

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

Can facts change minds?

Most people tend to assume their knowledge and ideas are based on a rational, objective analysis of information. And that’s sometimes the case. If it’s snowing outside, people don’t insist that it’s sunny and warm, no matter how much they might like it to be.

Similarly, if a person comes across some novel fact in the news, such as the discovery of a new type of plant in the Amazon, they might just absorb that information and go about their day.

But rationality and the ability to embrace new information goes out the window when it comes up against ideas that challenge one’s preexisting worldviews or social identities. Such information can feel like a personal attack, leading the body to release cortisol, a hormone associated with stress. So, certain facts can feel threatening or offensive.

Sometimes, people accept new information without much thought. But when new information challenges their existing beliefs, they may double down on their point of view.

What is my community saying?

Compounding what is happening in the brain is what’s happening in people’s communities. Humans are social animals who turn to others they trust to help them understand what’s what. People are attuned to what is considered normal or acceptable in their social environments. So if their social group holds a particular belief, they are more likely to adopt that belief too.

One’s cultural and political identities often dictate how they interpret the same information. This leads to disagreements even when presented with the same evidence.

These cultural identities explain why, for example, research finds that science-skeptical behaviors, such as vaccine hesitancy and climate denialism, tend to cluster in social and geographical pockets. In these pockets, people’s skepticism is reinforced by others with similar beliefs in their social network. In such cases, providing more evidence on a certain topic won’t help. And it may even result in people digging in their heels deeper to deny the evidence.

So if facts don’t necessarily change minds, what will?

Leveraging community networks

Recent research provides a solution for scientists and agencies hoping to correct misinformation: Rather than fighting against humans’ social nature, work with it.

When people see trusted individuals within their social networks holding a certain belief, that belief becomes more credible and easier to adopt. Leveraging those community connections can allow new ideas to gain traction.

One great example of using social networks to fight misinformation is how polio was eradicated in India. In 2009, India was the polio epicenter of the world, home to half of the world’s cases. These cases were largely clustered in vaccine-hesitant regions of the country. But by 2011, only two years later, India had only one case, and the country formally celebrated the eradication of polio in 2014.

Creating change in the face of science misinformation

How did India go from having half of the world’s cases to just one case in under two years?

Public health agencies asked volunteers from within vaccine-resistant communities to go on a listening campaign and become ambassadors for the vaccine. The volunteers were trained in interpersonal communication skills and tasked with spending time with parents. They built trust and rapport through regular visits.

Because the volunteers were known within the communities, they were able to make headway where health workers from urban areas had not. As they established rapport, hesitant parents shared their concerns, which typically went beyond polio to include other health issues.

Over time, more and more parents decided to vaccinate their children, until there was a tipping point and vaccination became a social norm. Perhaps most notably, the campaign led to full routine immunization rates in some high-risk regions of the country.

India’s incredible success emphasizes the importance of personal interactions for changing minds, which means moving beyond simply presenting the facts. Building trust, listening to concerns and engaging with communities in a meaningful way were integral to India’s eradication of polio.

Science misinformation and the power of conversations

Another example of using the power of social networks to talk about controversial science topics comes from a method called deep canvassing. Deep canvassing is a unique communication method that involves going door to door to have conversations with members of the public.

But it’s unlike traditional canvassing, which often focuses on rallying existing supporters. Deep canvassing deliberately seeks to engage with those who hold different viewpoints, focusing efforts in communities where the topic is controversial.

Canvassers are trained to ask questions to better understand the other person’s experiences and perspectives on the issue. And then they share their own personal stories. This helps to create a human connection, where both parties feel heard and respected. This connection can help to reduce the negative emotions that may emerge when someone is challenged to rethink their beliefs.

Neighbors United

One notable example of deep canvassing in action is the work of Neighbors United, an environmental nonprofit in Canada. They used a deep-canvassing approach to engage people in conversations about climate change.

They piloted the method in a rural, conservative community called Trail, home to one of the largest zinc and lead smelters in the world. Prior efforts to engage community members hadn’t had much of an effect. That’s because taking action on climate change was largely seen as being in conflict with how many people made their living.

But the deep-canvassing method worked. Going door to door, the canvassers listened to residents’ concerns, shared their own stories about the impact of climate change and highlighted local environmental successes.

As a result, 1 in 3 residents shifted their views about the importance of taking action to address climate change. This broad community support led the City Council to vote to transition to 100% renewable energy by 2050.

Working within social networks

Sociologist Anthony Giddens described interpersonal interactions between experts, such as doctors or scientists, and the public as access points. He argued that these points are vital for maintaining trust in governmental and scientific institutions, such as the Centers for Disease Control and Prevention or the Environmental Protection Agency.

These face-to-face interactions with experts can help people see them as kind, warm and professional, which can lead to trust.

These examples show that creating support for attitudes and behaviors based on science requires more than just presenting facts. It requires creating meaningful dialogue between skeptical groups and scientific messengers. It’s also a reminder that while social networks may serve to propagate misinformation, they can also be an important tool for addressing it.

Anne Toomey, Associate Professor of Environmental Studies and Science, Pace University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Bottom line: If you want to help combat science misinformation, work within your community and social network to have personal conversations and share stories.

Read more: Is social media polarization about to get worse?

The post Address science misinformation by building community first appeared on EarthSky.

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See Sirius, the brightest star in the night sky

View at EarthSky Community Photos. | Sergei Timofeevski shared this image from November 13, 2023. Sergei wrote: “The constellation Orion the Hunter and the star Sirius rising just above the eastern horizon in the Anza-Borrego Desert State Park, California.” Thank you, Sergei! Note bright Sirius is on the bottom, and Orion’s Belt pointing to it.

February is perfect for both Northern Hemisphere and Southern Hemisphere observers to view the brightest star in the sky: Sirius. As part of the constellation Canis Major the Greater Dog, Sirius also earns the nickname of the Dog Star. From the Northern Hemisphere, Sirius arcs across in the southern sky. From the Southern Hemisphere, it swings high overhead. It’s always easy to spot as the brightest point of light in its region of sky (unless a planet happens to be near it, like Jupiter and Mars are in 2025).

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

It’s a flashy rainbow star

Although white to blue-white in color, Sirius might be called a rainbow star, as it often flickers with many colors. The flickering colors are especially easy to notice when you spot Sirius low in the sky.

The brightness, twinkling and color changes sometimes prompt people to report Sirius as a UFO!

In fact, these changes are simply what happens when such a bright star as Sirius shines through the blanket of Earth’s atmosphere. The varying density and temperature of Earth’s air affect starlight, especially when we’re seeing the star low in the sky.

The shimmering and color changes happen for other stars, too, but these effects are more noticeable for Sirius because Sirius is so bright.

Finding Sirius

From the mid-northern latitudes such as most of the U.S., Sirius rises in the southeast, arcs across the southern sky, and sets in the southwest. From the Southern Hemisphere, Sirius arcs high overhead.

As seen from around the world, Sirius rises in mid-evening in December. By mid-April, Sirius is setting in the southwest in mid-evening.

Sirius is always easy to find. It’s the sky’s brightest star! Plus, anyone familiar with the constellation Orion can simply draw a line through Orion’s Belt to find this star. Sirius is roughly eight times as far from the Belt as the Belt is wide.

Sirius is the sky’s brightest star. You’ll always know it’s Sirius because Orion’s Belt – 3 stars in a short, straight row – points to it. Also, as seen from the latitudes like those in Florida, Texas or southern California, Canopus – the 2nd-brightest star – arcs across the south below Sirius on February evenings. From farther south on the sky’s dome, Sirius and Canopus cross higher in the sky, like almost-twin diamonds. Chart via EarthSky.

The mythology of Sirius

Sirius is well known as the Dog Star, because it’s the chief star in the constellation Canis Major the Greater Dog. Have you ever heard anyone speak of the dog days of summer? Sirius is behind the sun as seen from Earth in Northern Hemisphere summer. In late summer, it appears in the east before sunrise, near the sun in our sky. The early stargazers might have imagined the double-whammy of Sirius and the sun caused the hot weather, or dog days.

In ancient Egypt, the name Sirius signified its nature as scorching or sparkling. The star was associated with the Egyptian gods Osiris, Sopdet and other gods. Ancient Egyptians noted that Sirius rose just before the sun each year immediately prior to the annual flooding of the Nile River. Although the floods could bring destruction, they also brought new soil and new life.

Osiris was an Egyptian god of life, death, fertility and rebirth of plant life along the Nile. Sopdet – who might have an even closer association with the star Sirius – began as an agricultural deity in Egypt, also closely associated with the Nile. The Egyptian new year celebration was a festival known as the Coming of Sopdet.

More mythology of the Dog Star

In India, Sirius is sometimes known as Svana, the dog of Prince Yudhisthira. The prince and his four brothers, along with Svana, set out on a long and arduous journey to find the kingdom of heaven. However, one by one the brothers all abandoned the search until only Yudhisthira and his dog, Svana, remained. At long last they came to the gates of heaven. The gatekeeper, Indra, welcomed the prince but denied Svana entrance.

Yudhisthira was aghast and told Indra that he could not forsake his good and faithful servant and friend. His brothers, Yudhisthira said, had abandoned the journey to heaven to follow their hearts’ desires. But Svana, who had given his heart freely, chose to follow none but Yudhisthira. The prince said that, without his dog, he would forsake even heaven. This is what Indra had wanted to hear, and then he welcomed both the prince and the dog through the gates of heaven.

Sopdet, the ancient Egyptian personification of the star Sirius. Image via Jeff Dahl/ Wikimedia Commons (CC BY-SA 4.0).

The brightest star

Astronomers express the brightness of stars in terms of stellar magnitude. The smaller the number, the brighter the star.

The visual magnitude of Sirius is -1.44, lower – brighter – than any other star. There are brighter stars than Sirius in terms of actual energy and light output, but they are farther away and hence appear dimmer.

Normally, the only objects that outshine Sirius in our heavens are the sun, moon, Venus, Jupiter, Mars and Mercury (and usually Sirius outshines Mercury, too).

Not counting the sun, the second-brightest star in all of Earth’s sky – next-brightest after Sirius – is Canopus. It is visible from latitudes like those of the southern U.S.

The third-brightest and, as it happens, the closest major star to our sun is Alpha Centauri. However, it’s too far south in the sky to see easily from mid-northern latitudes.

View at EarthSky Community Photos. | Amit Raka submitted this image captured in India on January 25, 2025, and wrote: “We gazed upon a breathtaking celestial wonder—the Winter Circle, also known as the Winter Hexagon. This image showcases the brilliance of 6 of the brightest stars forming a giant hexagonal asterism in the winter night sky. The view was truly mesmerizing, leaving all in awe as they admired the countless stars and even spotted planets twinkling amidst the vast cosmic expanse.” Thank you, Amit!

The science of Sirius

At 8.6 light-years distance, Sirius is one of the nearest stars to us after the sun. By the way, a light year is nearly 6 trillion miles (9.6 trillion km)!

Sirius is classified by astronomers as an A type star. That means it’s a much hotter star than our sun; its surface temperature is about 17,000 degrees Fahrenheit (9,400 Celsius) in contrast to our sun’s 10,000 F (5,500 C). With slightly more than twice the mass of the sun and just less than twice its diameter, Sirius still puts out 26 times as much energy. It’s a main-sequence star, meaning it produces most of its energy by converting hydrogen into helium through nuclear fusion.

Sirius has a small, faint companion star appropriately called Sirius B or the Pup. That name signifies youth, but in fact the companion to Sirius is a white dwarf, a dead star. Once a mighty star, the Pup today is an Earth-sized ember, too faint to be seen without a telescope.

View at EarthSky Community Photos. | Michael Teoh at Heng Ee Observatory in Penang, Malaysia, captured this photo of Sirius A and Sirius B (a white dwarf, aka the Pup) on January 26, 2021. He used 30 1-second exposures and stacked them together to make faint Sirius B appear. Thank you, Michael!

The position of Sirius is RA: 06h 45m 08.9s, dec: -16° 42′ 58″.

Bottom line: Sirius is the brightest star in the night sky as seen from Earth and is visible from both hemispheres. And it lies just 8.6 light-years away in the constellation Canis Major the Greater Dog.

The post See Sirius, the brightest star in the night sky first appeared on EarthSky.

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View at EarthSky Community Photos. | Sergei Timofeevski shared this image from November 13, 2023. Sergei wrote: “The constellation Orion the Hunter and the star Sirius rising just above the eastern horizon in the Anza-Borrego Desert State Park, California.” Thank you, Sergei! Note bright Sirius is on the bottom, and Orion’s Belt pointing to it.

February is perfect for both Northern Hemisphere and Southern Hemisphere observers to view the brightest star in the sky: Sirius. As part of the constellation Canis Major the Greater Dog, Sirius also earns the nickname of the Dog Star. From the Northern Hemisphere, Sirius arcs across in the southern sky. From the Southern Hemisphere, it swings high overhead. It’s always easy to spot as the brightest point of light in its region of sky (unless a planet happens to be near it, like Jupiter and Mars are in 2025).

The 2025 EarthSky lunar calendar makes a great gift. Get yours today!

It’s a flashy rainbow star

Although white to blue-white in color, Sirius might be called a rainbow star, as it often flickers with many colors. The flickering colors are especially easy to notice when you spot Sirius low in the sky.

The brightness, twinkling and color changes sometimes prompt people to report Sirius as a UFO!

In fact, these changes are simply what happens when such a bright star as Sirius shines through the blanket of Earth’s atmosphere. The varying density and temperature of Earth’s air affect starlight, especially when we’re seeing the star low in the sky.

The shimmering and color changes happen for other stars, too, but these effects are more noticeable for Sirius because Sirius is so bright.

Finding Sirius

From the mid-northern latitudes such as most of the U.S., Sirius rises in the southeast, arcs across the southern sky, and sets in the southwest. From the Southern Hemisphere, Sirius arcs high overhead.

As seen from around the world, Sirius rises in mid-evening in December. By mid-April, Sirius is setting in the southwest in mid-evening.

Sirius is always easy to find. It’s the sky’s brightest star! Plus, anyone familiar with the constellation Orion can simply draw a line through Orion’s Belt to find this star. Sirius is roughly eight times as far from the Belt as the Belt is wide.

Sirius is the sky’s brightest star. You’ll always know it’s Sirius because Orion’s Belt – 3 stars in a short, straight row – points to it. Also, as seen from the latitudes like those in Florida, Texas or southern California, Canopus – the 2nd-brightest star – arcs across the south below Sirius on February evenings. From farther south on the sky’s dome, Sirius and Canopus cross higher in the sky, like almost-twin diamonds. Chart via EarthSky.

The mythology of Sirius

Sirius is well known as the Dog Star, because it’s the chief star in the constellation Canis Major the Greater Dog. Have you ever heard anyone speak of the dog days of summer? Sirius is behind the sun as seen from Earth in Northern Hemisphere summer. In late summer, it appears in the east before sunrise, near the sun in our sky. The early stargazers might have imagined the double-whammy of Sirius and the sun caused the hot weather, or dog days.

In ancient Egypt, the name Sirius signified its nature as scorching or sparkling. The star was associated with the Egyptian gods Osiris, Sopdet and other gods. Ancient Egyptians noted that Sirius rose just before the sun each year immediately prior to the annual flooding of the Nile River. Although the floods could bring destruction, they also brought new soil and new life.

Osiris was an Egyptian god of life, death, fertility and rebirth of plant life along the Nile. Sopdet – who might have an even closer association with the star Sirius – began as an agricultural deity in Egypt, also closely associated with the Nile. The Egyptian new year celebration was a festival known as the Coming of Sopdet.

More mythology of the Dog Star

In India, Sirius is sometimes known as Svana, the dog of Prince Yudhisthira. The prince and his four brothers, along with Svana, set out on a long and arduous journey to find the kingdom of heaven. However, one by one the brothers all abandoned the search until only Yudhisthira and his dog, Svana, remained. At long last they came to the gates of heaven. The gatekeeper, Indra, welcomed the prince but denied Svana entrance.

Yudhisthira was aghast and told Indra that he could not forsake his good and faithful servant and friend. His brothers, Yudhisthira said, had abandoned the journey to heaven to follow their hearts’ desires. But Svana, who had given his heart freely, chose to follow none but Yudhisthira. The prince said that, without his dog, he would forsake even heaven. This is what Indra had wanted to hear, and then he welcomed both the prince and the dog through the gates of heaven.

Sopdet, the ancient Egyptian personification of the star Sirius. Image via Jeff Dahl/ Wikimedia Commons (CC BY-SA 4.0).

The brightest star

Astronomers express the brightness of stars in terms of stellar magnitude. The smaller the number, the brighter the star.

The visual magnitude of Sirius is -1.44, lower – brighter – than any other star. There are brighter stars than Sirius in terms of actual energy and light output, but they are farther away and hence appear dimmer.

Normally, the only objects that outshine Sirius in our heavens are the sun, moon, Venus, Jupiter, Mars and Mercury (and usually Sirius outshines Mercury, too).

Not counting the sun, the second-brightest star in all of Earth’s sky – next-brightest after Sirius – is Canopus. It is visible from latitudes like those of the southern U.S.

The third-brightest and, as it happens, the closest major star to our sun is Alpha Centauri. However, it’s too far south in the sky to see easily from mid-northern latitudes.

View at EarthSky Community Photos. | Amit Raka submitted this image captured in India on January 25, 2025, and wrote: “We gazed upon a breathtaking celestial wonder—the Winter Circle, also known as the Winter Hexagon. This image showcases the brilliance of 6 of the brightest stars forming a giant hexagonal asterism in the winter night sky. The view was truly mesmerizing, leaving all in awe as they admired the countless stars and even spotted planets twinkling amidst the vast cosmic expanse.” Thank you, Amit!

The science of Sirius

At 8.6 light-years distance, Sirius is one of the nearest stars to us after the sun. By the way, a light year is nearly 6 trillion miles (9.6 trillion km)!

Sirius is classified by astronomers as an A type star. That means it’s a much hotter star than our sun; its surface temperature is about 17,000 degrees Fahrenheit (9,400 Celsius) in contrast to our sun’s 10,000 F (5,500 C). With slightly more than twice the mass of the sun and just less than twice its diameter, Sirius still puts out 26 times as much energy. It’s a main-sequence star, meaning it produces most of its energy by converting hydrogen into helium through nuclear fusion.

Sirius has a small, faint companion star appropriately called Sirius B or the Pup. That name signifies youth, but in fact the companion to Sirius is a white dwarf, a dead star. Once a mighty star, the Pup today is an Earth-sized ember, too faint to be seen without a telescope.

View at EarthSky Community Photos. | Michael Teoh at Heng Ee Observatory in Penang, Malaysia, captured this photo of Sirius A and Sirius B (a white dwarf, aka the Pup) on January 26, 2021. He used 30 1-second exposures and stacked them together to make faint Sirius B appear. Thank you, Michael!

The position of Sirius is RA: 06h 45m 08.9s, dec: -16° 42′ 58″.

Bottom line: Sirius is the brightest star in the night sky as seen from Earth and is visible from both hemispheres. And it lies just 8.6 light-years away in the constellation Canis Major the Greater Dog.

The post See Sirius, the brightest star in the night sky first appeared on EarthSky.

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Earth’s inner core changes shape over time

Watch a video about how Earth’s inner core changes shape over time, from the University of Southern California.

Earth’s inner core is not perfectly solid, according to new research.

Its outer surface changes shape due to interactions with the molten outer core.

Analysis of seismic waves from 120 earthquakes showed evidence that the inner core is affected by outer core turbulence.

Earth’s inner core is less solid than we once thought

Earth’s inner core lies some 3,000 miles (4,800 km) below our world’s surface. Scientists long thought the inner core was a solid sphere. But new research shows it’s not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core.

In this study, scientists analyzed seismic waves – vibrations that move through the Earth – generated by earthquakes. They studied seismic waves from 120 earthquakes, most originating at known faults at Antarctica’s South Sandwich Islands, between 1991 and 2024.

The waves these earthquakes generated traveled through the center of the Earth. Then seismographs picked them up almost on the other side of the world, in Fairbanks, Alaska and Yellowknife, Canada.

Researchers published their findings in the peer-reviewed journal Nature Geoscience on February 10, 2025.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

An unexpected discovery

The original purpose of the study was to better characterize the rotation of the Earth’s inner core, which is about 1,520 miles (2,440 km) in diameter. Scientists once thought the solid inner core rotated at the same rate as the rest of Earth. Then, studies about two decades ago suggested it may have been rotating a bit faster.

However, in June 2024, the same team behind this new study confirmed the inner core’s rotation had been slowing down since 2010. Therefore, they wanted to use the South Sandwich Islands earthquake data to continue studying the rotation.

Lead author John Vidale of USC Dornsife said:

But as I was analyzing multiple decades’ worth of seismograms, one dataset of seismic waves curiously stood out from the rest. Later on, I’d realize I was staring at evidence the inner core is not solid.

He said he was initially puzzled by the one dataset from Yellowknife, Canada. But as his team refined their analysis of those seismic waves, they realized they were seeing physical activity in the inner core.

A graphic showing the interior of the Earth, with the inner core in the center. New research shows the inner core is not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core. Image via USC Graphic/ Edward Sotelo.

What’s causing changes to the inner core?

The scientists think they’re seeing changes over time in the shape of the inner core’s outer boundary. It could be due to interactions between the inner and outer core. Vidale commented:

The molten outer core is widely known to be turbulent, but its turbulence had not been observed to disrupt its neighbor, the inner core, on a human timescale. What we’re observing in this study for the first time is likely the outer core disturbing the inner core.

He added that this discovery could help scientists better understand the dynamics of Earth’s core, as well as our planet’s thermal properties and magnetic field.

Bottom line: Scientists report that Earth’s inner core is not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core.

Source: Annual-scale variability in both the rotation rate and near surface of Earth’s inner core

Via University of Southern California

Read more: Earth’s core has a huge, hidden donut shape

The post Earth’s inner core changes shape over time first appeared on EarthSky.

from EarthSky https://ift.tt/kP517ug

Watch a video about how Earth’s inner core changes shape over time, from the University of Southern California.

Earth’s inner core is not perfectly solid, according to new research.

Its outer surface changes shape due to interactions with the molten outer core.

Analysis of seismic waves from 120 earthquakes showed evidence that the inner core is affected by outer core turbulence.

Earth’s inner core is less solid than we once thought

Earth’s inner core lies some 3,000 miles (4,800 km) below our world’s surface. Scientists long thought the inner core was a solid sphere. But new research shows it’s not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core.

In this study, scientists analyzed seismic waves – vibrations that move through the Earth – generated by earthquakes. They studied seismic waves from 120 earthquakes, most originating at known faults at Antarctica’s South Sandwich Islands, between 1991 and 2024.

The waves these earthquakes generated traveled through the center of the Earth. Then seismographs picked them up almost on the other side of the world, in Fairbanks, Alaska and Yellowknife, Canada.

Researchers published their findings in the peer-reviewed journal Nature Geoscience on February 10, 2025.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

An unexpected discovery

The original purpose of the study was to better characterize the rotation of the Earth’s inner core, which is about 1,520 miles (2,440 km) in diameter. Scientists once thought the solid inner core rotated at the same rate as the rest of Earth. Then, studies about two decades ago suggested it may have been rotating a bit faster.

However, in June 2024, the same team behind this new study confirmed the inner core’s rotation had been slowing down since 2010. Therefore, they wanted to use the South Sandwich Islands earthquake data to continue studying the rotation.

Lead author John Vidale of USC Dornsife said:

But as I was analyzing multiple decades’ worth of seismograms, one dataset of seismic waves curiously stood out from the rest. Later on, I’d realize I was staring at evidence the inner core is not solid.

He said he was initially puzzled by the one dataset from Yellowknife, Canada. But as his team refined their analysis of those seismic waves, they realized they were seeing physical activity in the inner core.

A graphic showing the interior of the Earth, with the inner core in the center. New research shows the inner core is not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core. Image via USC Graphic/ Edward Sotelo.

What’s causing changes to the inner core?

The scientists think they’re seeing changes over time in the shape of the inner core’s outer boundary. It could be due to interactions between the inner and outer core. Vidale commented:

The molten outer core is widely known to be turbulent, but its turbulence had not been observed to disrupt its neighbor, the inner core, on a human timescale. What we’re observing in this study for the first time is likely the outer core disturbing the inner core.

He added that this discovery could help scientists better understand the dynamics of Earth’s core, as well as our planet’s thermal properties and magnetic field.

Bottom line: Scientists report that Earth’s inner core is not perfectly solid. Its surface changes shape over time due to interactions with the outer molten core.

Source: Annual-scale variability in both the rotation rate and near surface of Earth’s inner core

Via University of Southern California

Read more: Earth’s core has a huge, hidden donut shape

The post Earth’s inner core changes shape over time first appeared on EarthSky.

from EarthSky https://ift.tt/kP517ug

Cassiopeia the Queen reigns in the February sky

You can find Cassiopeia the Queen in the northwest in the evening around the month of February. It’s one of the easiest constellations to spot! It has the shape of an M or W. If you have a dark sky, you can also look above Cassiopeia for a famous binocular object, the Double Cluster in Perseus. Chart via EarthSky.

Cassiopeia the Queen in late winter and early spring

On late northern winter evenings and throughout spring, Cassiopeia the Queen descends in her throne in the northwest after nightfall. Cassiopeia is one of the easiest constellations to spot because of its distinctive shape. Cassiopeia looks like the letter W or M. Look for the Queen as your sky gets dark in February and March. She’ll be lower in the northwest as spring begins to unfold. For those in the northern U.S. and Canada, Cassiopeia is circumpolar, or above the horizon all night every night.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

The stars of Cassiopeia

Cassiopeia is home to five bright stars that form the W shape. Some describe these stars as outlining the chair – or throne – she sits upon. If you’re viewing Cassiopeia as the letter W, the stars, from left to right, are Segin, Ruchbah, Gamma Cassiopeiae, Schedar and Caph.

Many observers use the arrow shape of Cassiopeia to point their way to the Andromeda galaxy. Image via Wikimedia Commons (CC BY 3.0).

How to find Cassiopeia

Cassiopeia is opposite the Big Dipper in the northern sky. That is, the two constellations lie on opposite sides of the pole star, Polaris. So when Cassiopeia is high in the sky, as it is on evenings from about September through February, the Big Dipper is low in the sky. Every March, when the Dipper is ascending in the northeast, getting ready to appear prominently again in the evening sky, Cassiopeia is descending in the northwest.

The Big Dipper and the W-shaped constellation Cassiopeia circle around Polaris, the North Star, in a period of 23 hours and 56 minutes. The Dipper is circumpolar at 41 degrees north latitude, and all latitudes farther north. Image via Mjchael/ Wikipedia (CC BY-SA 2.5).

Neighboring star clusters

If you have a dark sky, look across the border of Cassiopeia into Perseus the Hero for a famous binocular object. It’s the Double Cluster in Perseus. They are open star clusters, each of which consists of young stars still moving together from the primordial cloud of gas and dust that gave birth to them.

In fact, these clusters have a unique set of mismatched names: H and Chi Persei. Their names are from two different alphabets, the Greek and the Roman. Stars have Greek letter names, but most star clusters don’t. Johann Bayer (1572-1625) gave Chi Persei – the cluster on the top – its Greek letter name. Then, it’s said, he ran out of Greek letters. That’s when he used a Roman letter – the letter H – to name the other cluster.

Upside-down Cassiopeia, as depicted on Mercator celestial globe in 1551. Image via Harvard Map Collection/ Wikipedia (public domain).

Lore of the Queen

In sky lore and in Greek mythology, Cassiopeia was a beautiful and vain queen of Ethiopia. It’s said that she committed the sin of pride by boasting that both she and her daughter Andromeda were more beautiful than Nereids, or sea nymphs.

Her boast angered Poseidon, god of the sea, who sent a sea monster (Cetus the Whale) to ravage the kingdom. To pacify the monster, Cassiopeia’s daughter, Princess Andromeda, was left tied to a rock by the sea. Then, when Cetus was about to devour her, Perseus the Hero happened by on Pegasus the Winged Horse.

Then, Perseus rescued the princess, and all lived happily … and the gods were pleased, so all of these characters were elevated to the heavens as stars.

But – because of her vanity – Cassiopeia suffered an indignity. At some times of the night or year, this constellation has more the shape of the letter M, and you might imagine the Queen reclining on her starry throne. Meanwhile, at other times of the year or night – as in the wee hours between midnight and dawn in February and March – Cassiopeia’s Chair dips below the celestial pole. And then this constellation appears to us on Earth more like the letter W.

That’s when the Lady of the Chair – as she is sometimes called – is upside-down and said to hang on for dear life. If Cassiopeia the Queen lets go, she will drop from the sky into the ocean below, where the Nereids must still be waiting.

Bottom line: The constellation Cassiopeia the Queen has the distinct shape of a W or M. You’ll find her descending in her throne on late northern winter evenings and throughout spring nights.

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You can find Cassiopeia the Queen in the northwest in the evening around the month of February. It’s one of the easiest constellations to spot! It has the shape of an M or W. If you have a dark sky, you can also look above Cassiopeia for a famous binocular object, the Double Cluster in Perseus. Chart via EarthSky.

Cassiopeia the Queen in late winter and early spring

On late northern winter evenings and throughout spring, Cassiopeia the Queen descends in her throne in the northwest after nightfall. Cassiopeia is one of the easiest constellations to spot because of its distinctive shape. Cassiopeia looks like the letter W or M. Look for the Queen as your sky gets dark in February and March. She’ll be lower in the northwest as spring begins to unfold. For those in the northern U.S. and Canada, Cassiopeia is circumpolar, or above the horizon all night every night.

2025 EarthSky lunar calendar is available now. A unique and beautiful poster-sized calendar with phases of the moon for every night of the year. Get yours today!

The stars of Cassiopeia

Cassiopeia is home to five bright stars that form the W shape. Some describe these stars as outlining the chair – or throne – she sits upon. If you’re viewing Cassiopeia as the letter W, the stars, from left to right, are Segin, Ruchbah, Gamma Cassiopeiae, Schedar and Caph.

Many observers use the arrow shape of Cassiopeia to point their way to the Andromeda galaxy. Image via Wikimedia Commons (CC BY 3.0).

How to find Cassiopeia

Cassiopeia is opposite the Big Dipper in the northern sky. That is, the two constellations lie on opposite sides of the pole star, Polaris. So when Cassiopeia is high in the sky, as it is on evenings from about September through February, the Big Dipper is low in the sky. Every March, when the Dipper is ascending in the northeast, getting ready to appear prominently again in the evening sky, Cassiopeia is descending in the northwest.

The Big Dipper and the W-shaped constellation Cassiopeia circle around Polaris, the North Star, in a period of 23 hours and 56 minutes. The Dipper is circumpolar at 41 degrees north latitude, and all latitudes farther north. Image via Mjchael/ Wikipedia (CC BY-SA 2.5).

Neighboring star clusters

If you have a dark sky, look across the border of Cassiopeia into Perseus the Hero for a famous binocular object. It’s the Double Cluster in Perseus. They are open star clusters, each of which consists of young stars still moving together from the primordial cloud of gas and dust that gave birth to them.

In fact, these clusters have a unique set of mismatched names: H and Chi Persei. Their names are from two different alphabets, the Greek and the Roman. Stars have Greek letter names, but most star clusters don’t. Johann Bayer (1572-1625) gave Chi Persei – the cluster on the top – its Greek letter name. Then, it’s said, he ran out of Greek letters. That’s when he used a Roman letter – the letter H – to name the other cluster.

Upside-down Cassiopeia, as depicted on Mercator celestial globe in 1551. Image via Harvard Map Collection/ Wikipedia (public domain).

Lore of the Queen

In sky lore and in Greek mythology, Cassiopeia was a beautiful and vain queen of Ethiopia. It’s said that she committed the sin of pride by boasting that both she and her daughter Andromeda were more beautiful than Nereids, or sea nymphs.

Her boast angered Poseidon, god of the sea, who sent a sea monster (Cetus the Whale) to ravage the kingdom. To pacify the monster, Cassiopeia’s daughter, Princess Andromeda, was left tied to a rock by the sea. Then, when Cetus was about to devour her, Perseus the Hero happened by on Pegasus the Winged Horse.

Then, Perseus rescued the princess, and all lived happily … and the gods were pleased, so all of these characters were elevated to the heavens as stars.

But – because of her vanity – Cassiopeia suffered an indignity. At some times of the night or year, this constellation has more the shape of the letter M, and you might imagine the Queen reclining on her starry throne. Meanwhile, at other times of the year or night – as in the wee hours between midnight and dawn in February and March – Cassiopeia’s Chair dips below the celestial pole. And then this constellation appears to us on Earth more like the letter W.

That’s when the Lady of the Chair – as she is sometimes called – is upside-down and said to hang on for dear life. If Cassiopeia the Queen lets go, she will drop from the sky into the ocean below, where the Nereids must still be waiting.

Bottom line: The constellation Cassiopeia the Queen has the distinct shape of a W or M. You’ll find her descending in her throne on late northern winter evenings and throughout spring nights.

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Extreme cold is impacting more than 1,000 miles of US

Extreme cold is hitting the U.S. People are bundling up! Image via Demeter Attila/ Pexels.

Dangerous cold in mid-US on Wednesday

As of late Tuesday night and early Wednesday morning, Extreme Cold Warnings stretched over 1,300 miles (2,100 km) of the continental United States, from North Dakota down through South Central Texas. Record cold temperatures and dangerously low wind chills are expected across this region today.

While the specific criteria for Extreme Cold Warnings vary from region to region, the National Weather Service says that an Extreme Cold Warning is issued when temperatures or wind chill values (what it feels like with the wind factored in) are forecast to be dangerously cold.

Parts of North Dakota are waking up on Wednesday to temperatures 30 to 40 degrees below 0 degrees Fahrenheit (-18 C). Factoring in the wind, it will “feel like” 30 to 50 below 0 degrees Fahrenheit! With these extreme cold temperatures, frostbite can occur in a matter of minutes. Unfortunately, the afternoon won’t bring much relief, as high temperatures won’t make it above 0 degrees.

While the northern plains of the United States are no stranger to cold, this time of year the temperatures should range from 9 degrees (-13 C) in the morning, to 29 degrees (-1.6 C) in the afternoon for the Bismarck, North Dakota, area. This is more than 30 degrees colder than normal!

Fortunately, the Extreme Cold Warning is expected to be short-lived. It’s expected to expire by midday on Wednesday, with temperatures warming above average by the end of the week.

Extreme cold. How far south?

On the southern end of the Extreme Cold Warning is San Antonio, Texas. The warnings are in place for Wednesday morning, but also Wednesday night into Thursday morning. Temperatures on Thursday morning will drop into the low 20s (-6 C), but strong winds will create wind chill values in the single digits.

While these temperatures may feel mild to the people in North Dakota, for this part of Texas, it is extreme!

San Antonio this time of year should have temperatures ranging from 46 degrees (7 C) in the morning to 69 (20 C) by the afternoon. The forecast for this area Thursday will range from 24 degrees (-4 C) in the morning to 43 (6 C) by the afternoon, a difference of more than 20 degrees colder than normal.

Note that that the record for the coldest high temperature in San Antonio for Thursday, February 20, is 42 degrees (5.5 C), and was set back in 1904.

Extreme Cold Warnings Issued for South Central Texas. Image via National Weather Service Austin/San Antonio, Texas.

Why so cold?

An Arctic high pressure has been moving south out of Canada and into the United States, taking the frigid air down through Nebraska, Kansas, Oklahoma and as far south as the Gulf Coast of Texas. This Arctic high pressure will keep the middle part of the United States cold for a number of days before it moves east Friday and into the weekend, allowing this part of the country to thaw after their deep freeze. (South Central Texas is forecast to warm back into the upper 70s and low 80s by early next week!)

Staying safe in cold weather

As we’ve noticed with the difference in “extreme cold” from one part of the country to another, what is considered dangerously cold is subjective, based on your climate and location. However, no matter what is considered “extreme cold” for you, it’s important to stay safe. While everyone is at risk during cold weather, certain groups of people can be more susceptible to impacts from extreme cold.

These groups include people who are out in the elements for long periods of time, like the unhoused community and outdoor workers. The very young or elderly are not able to deal with the cold as easily, as well as those who are immunocompromised or have chronic illnesses. These people, if possible, should avoid spending time outside during extreme cold, and if they can’t, they should cover any exposed skin with layers of warm clothing.

Check on your friends, family and neighbors during extreme cold to make sure they are safe. Also, underserved and underprivileged communities tend to struggle in extreme temperatures (hot and cold) as some may not be able to afford running their heat or air conditioning for long periods of time. This is another reason to be a good neighbor and check on those around you during the cold winter months, and support community efforts to help people in your area.

A list of vulnerable populations that are impacted the most during extreme cold. Image via the National Weather Service.

Warning signs of frostbite

For those at the northern end of this extreme cold snap on Wednesday, frostbite will occur in a matter of minutes. If you are concerned that you or a family member has frostbite, the Center for Disease Control says to look out for these warning signs:

• A white or yellow-grey area on the skin
• The skin feeling too firm, or waxy
• Numbness in the suspected frostbite area

If you see these warning signs, immediately find medical care. You should also get the person to a warm room, but do not rub the area with frostbite or walk on feet that have frostbite, as that could cause more damage. If you can’t get to a doctor, you can put the part of the body with frostbite into warm, but not hot, water. Do not warm the affected area with a heating pad, or near a stove, radiator or fireplace. This is not a substitute for medical attention, and you should still seek help immediately.

Warning signs of hypothermia

While frostbite can happen quickly, hypothermia typically happens over a long period of exposure to the cold, even with an air temperature only as low at 40 degrees Fahrenheit (4 C). Hypothermia is when your body temperature drops too low, affecting your brain and major bodily movement and functions. The warning signs for hypothermia are:

• Extreme shivering
• Exhaustion and sleepiness
• Confusion
• Stiff muscles
• Slurred speech

If you see these warning signs, as with frostbite immediately seek medical attention. In the meantime, get the person to a warm area, and if they have on wet clothing, remove that. If you have an electric blanket, use that to warm the person around their chest, neck, head and groin. You can also give the person warm (non-alcoholic!) drinks, and keep them wrapped in warm, dry blankets until medical help has arrived.

Bottom Line: Extreme cold is impacting thousands of miles of the United States Wednesday and Thursday with temperatures running 20 to 30 degrees below average. While extreme cold is different across the country, you need to do what you can to avoid illness related to cold.

Read more: The National Weather Service recently simplified its cold weather watches, warnings and advisories.

Powerful winter storm to bring heavy snow, ice, tornado risk

Source: National Weather Service

Source: Centers for Disease Control and Prevention

The post Extreme cold is impacting more than 1,000 miles of US first appeared on EarthSky.

from EarthSky https://ift.tt/aZPMToq

Extreme cold is hitting the U.S. People are bundling up! Image via Demeter Attila/ Pexels.

Dangerous cold in mid-US on Wednesday

As of late Tuesday night and early Wednesday morning, Extreme Cold Warnings stretched over 1,300 miles (2,100 km) of the continental United States, from North Dakota down through South Central Texas. Record cold temperatures and dangerously low wind chills are expected across this region today.

While the specific criteria for Extreme Cold Warnings vary from region to region, the National Weather Service says that an Extreme Cold Warning is issued when temperatures or wind chill values (what it feels like with the wind factored in) are forecast to be dangerously cold.

Parts of North Dakota are waking up on Wednesday to temperatures 30 to 40 degrees below 0 degrees Fahrenheit (-18 C). Factoring in the wind, it will “feel like” 30 to 50 below 0 degrees Fahrenheit! With these extreme cold temperatures, frostbite can occur in a matter of minutes. Unfortunately, the afternoon won’t bring much relief, as high temperatures won’t make it above 0 degrees.

While the northern plains of the United States are no stranger to cold, this time of year the temperatures should range from 9 degrees (-13 C) in the morning, to 29 degrees (-1.6 C) in the afternoon for the Bismarck, North Dakota, area. This is more than 30 degrees colder than normal!

Fortunately, the Extreme Cold Warning is expected to be short-lived. It’s expected to expire by midday on Wednesday, with temperatures warming above average by the end of the week.

Extreme cold. How far south?

On the southern end of the Extreme Cold Warning is San Antonio, Texas. The warnings are in place for Wednesday morning, but also Wednesday night into Thursday morning. Temperatures on Thursday morning will drop into the low 20s (-6 C), but strong winds will create wind chill values in the single digits.

While these temperatures may feel mild to the people in North Dakota, for this part of Texas, it is extreme!

San Antonio this time of year should have temperatures ranging from 46 degrees (7 C) in the morning to 69 (20 C) by the afternoon. The forecast for this area Thursday will range from 24 degrees (-4 C) in the morning to 43 (6 C) by the afternoon, a difference of more than 20 degrees colder than normal.

Note that that the record for the coldest high temperature in San Antonio for Thursday, February 20, is 42 degrees (5.5 C), and was set back in 1904.

Extreme Cold Warnings Issued for South Central Texas. Image via National Weather Service Austin/San Antonio, Texas.

Why so cold?

An Arctic high pressure has been moving south out of Canada and into the United States, taking the frigid air down through Nebraska, Kansas, Oklahoma and as far south as the Gulf Coast of Texas. This Arctic high pressure will keep the middle part of the United States cold for a number of days before it moves east Friday and into the weekend, allowing this part of the country to thaw after their deep freeze. (South Central Texas is forecast to warm back into the upper 70s and low 80s by early next week!)

Staying safe in cold weather

As we’ve noticed with the difference in “extreme cold” from one part of the country to another, what is considered dangerously cold is subjective, based on your climate and location. However, no matter what is considered “extreme cold” for you, it’s important to stay safe. While everyone is at risk during cold weather, certain groups of people can be more susceptible to impacts from extreme cold.

These groups include people who are out in the elements for long periods of time, like the unhoused community and outdoor workers. The very young or elderly are not able to deal with the cold as easily, as well as those who are immunocompromised or have chronic illnesses. These people, if possible, should avoid spending time outside during extreme cold, and if they can’t, they should cover any exposed skin with layers of warm clothing.

Check on your friends, family and neighbors during extreme cold to make sure they are safe. Also, underserved and underprivileged communities tend to struggle in extreme temperatures (hot and cold) as some may not be able to afford running their heat or air conditioning for long periods of time. This is another reason to be a good neighbor and check on those around you during the cold winter months, and support community efforts to help people in your area.

A list of vulnerable populations that are impacted the most during extreme cold. Image via the National Weather Service.

Warning signs of frostbite

For those at the northern end of this extreme cold snap on Wednesday, frostbite will occur in a matter of minutes. If you are concerned that you or a family member has frostbite, the Center for Disease Control says to look out for these warning signs:

• A white or yellow-grey area on the skin
• The skin feeling too firm, or waxy
• Numbness in the suspected frostbite area

If you see these warning signs, immediately find medical care. You should also get the person to a warm room, but do not rub the area with frostbite or walk on feet that have frostbite, as that could cause more damage. If you can’t get to a doctor, you can put the part of the body with frostbite into warm, but not hot, water. Do not warm the affected area with a heating pad, or near a stove, radiator or fireplace. This is not a substitute for medical attention, and you should still seek help immediately.

Warning signs of hypothermia

While frostbite can happen quickly, hypothermia typically happens over a long period of exposure to the cold, even with an air temperature only as low at 40 degrees Fahrenheit (4 C). Hypothermia is when your body temperature drops too low, affecting your brain and major bodily movement and functions. The warning signs for hypothermia are:

• Extreme shivering
• Exhaustion and sleepiness
• Confusion
• Stiff muscles
• Slurred speech

If you see these warning signs, as with frostbite immediately seek medical attention. In the meantime, get the person to a warm area, and if they have on wet clothing, remove that. If you have an electric blanket, use that to warm the person around their chest, neck, head and groin. You can also give the person warm (non-alcoholic!) drinks, and keep them wrapped in warm, dry blankets until medical help has arrived.

Bottom Line: Extreme cold is impacting thousands of miles of the United States Wednesday and Thursday with temperatures running 20 to 30 degrees below average. While extreme cold is different across the country, you need to do what you can to avoid illness related to cold.

Read more: The National Weather Service recently simplified its cold weather watches, warnings and advisories.

Powerful winter storm to bring heavy snow, ice, tornado risk

Source: National Weather Service

Source: Centers for Disease Control and Prevention

The post Extreme cold is impacting more than 1,000 miles of US first appeared on EarthSky.

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