Scientists warn rapid melting of Himalayan glaciers will impact us all



Arshad R. Zargar
Thu, June 22, 2023 

New Delhi — Glaciers in the Hindu Kush region of the Himalaya mountains are melting at the fastest rate ever and could shed as much as 80% of their ice by the end of this century if global warming continues unchecked, a group of international scientists warned in an alarming new report.

The study says the melting of the glaciers will directly impact billions of people in Asia — causing floods, landslides, avalanches and food shortages as farmland is inundated. Indirectly, the melting of such a vast reserve of fresh water could impact countries as far away as the United States, even the whole of humanity, according to the report by the Nepal-based International Centre for Integrated Mountain Development (ICIMOD).

The academic paper warns the ice and snow reserves in the Hindu Kush Himalayas (HKH) region are melting at an "unprecedented" rate and that the environmental changes to the sensitive region are "largely irreversible."

Glaciers are seen in the Pamir Mountains, a range in Central Asia formed by the junction of the Himalayas, Tian Shan, Karakoram, Kunlun and Hindu Kush mountain ranges, as seen in a file photo taken from the Karakoram Highway, in Xinjiang, China. / Credit: The Pamir Mountains are a mountain range in Central Asia formed by the junction of the Himalayas, Tian Shan, Karakoram, Kunlun and Hindu Kush mountain ranges. They are among the world's highest mountains and since Victorian times they have been known as 

The HKH region spans roughly 2,175 miles, from Afghanistan to Myanmar, and is home to the highest mountains in the world, including Mount Everest. It contains the largest volume of ice on Earth outside the two polar regions and is the source of water for 12 rivers that flow through 16 Asian nations.

Those rivers provide fresh water to some 240 million people living in the HKH region, and about 1.65 billion people further downstream, the report says.

For all of those people, the melting of the glaciers would be a disaster. The report says they will face extreme weather events and crop loss that will force mass-migration.

Deadly floods and avalanches in the Himalayan region have already increased over the past decade or so, and scientists have linked the greater frequency and intensity of the disasters to climate change and global warming.

The ICIMOD report lays out three potential scenarios for the glaciers of the HKH: If there is a 1.5-2 degree Celsius increase in the Earth's average temperature above pre-industrial levels, the glaciers will lose 30% to 50% of their ice volume by 2100. If the global temperature rises by 3 degrees Celsius, the glaciers could lose 75% of their ice and, with a 4-degree rise, the researchers say there will be a loss of up to 80% of the ice in the HKH.

"These projections are of very high confidence as we say in the scientific language," Dr. Philippus Wester, the ICIMOD's Chief Scientist on Water Resources Management and the lead editor of the report, told CBS News. "In layman's language, it means we have no doubt whatsoever that at 2 degrees Celsius global warming, we will lose 50% of the glacial ice mass in the region."

The report notes that the Himalayan glaciers lost ice at a rate 65% faster between 2010 and 2019 than over the previous decade (2001-2010).

"This is a lot, this is alarming," Wester told CBS News."On human time scales, we have never seen glacial melt this rapid, this fast… this is unprecedented."

Other research shows Mount Everest's glaciers have lost the equivalent of 2,000 years' worth of ice over just the past three decades. In a 2019 report, the ICIMOD said the Himalayan glaciers of the region would lose at least one third of their ice if the average global temperature was limited to 1.5 degrees Celsius. But with new technology and more data becoming available over the last five years, the scientists found circumstances worse than they expected, Wester said.

Global impact of the melting Himalayan glaciers

The impacts of the rapid glacial melt in the Himalayas will be felt around the world, Izabella Koziell, deputy director general of the ICIMOD, CBS News this week [video available at the top of this article].

"Even if this feels remote to us sitting far away, it is going to affect us — whether that is through mass people movement or sea-level rise. When the glaciers in the Himalayas melt, the ice sheets in Greenland, Arctic and Antarctic are also melting. This means there will be sea level rise, there will be quite dramatic changes in ocean circulation as a result of increase in fresh water into oceans, and this will have huge impacts on us," Koziell said.

"The people who are losing their livelihoods, of which there are 2 billion people — that's a quarter of the world's population — where will they go? They will have to go and find safer places and we will have to offer those safer places for them to live," Koziell said.

Earlier this month, scientists warned at the Bonn Climate Change Conference of the worrying speed and scale of ice-melt worldwide. Another study, published last year, said the Arctic could start to see periods during the summer without any ice remaining at all by 2030, even if emissions are cut drastically.

"Clarion call" for urgent climate action

Scientists are calling for urgent action to slow global warming to preserve as much of the ice mass in the Himalayas as possible.

"To prevent additional ice loss, greenhouse gas emissions must be reduced through the use of clean and renewable energy sources… cooperation among Himalayan nations and international organizations is required," Professor Anjal Prakash, an author on the United Nations' Intergovernmental Panel on Climate Change (IPCC), told CBS News.

"We need to reduce our greenhouse gas emissions as quickly as we can. The less melt we have, the better it is because it takes such a long time to recover from that loss," the ICIMOD's lead editor Wester told CBS News.

The U.N.'s IPCC says limiting warming to around 1.5 degrees Celsius requires global greenhouse gas emissions to peak before 2025, and be reduced by 43% by 2030. The world is not currently on course to keep those targets within reach.

"This is a clarion call," Wester told CBS News. "The world is not doing enough because we are still seeing an increase in the emissions year-on-year. We are not even at the point of a turnaround in terms of emissions."

"The change we are causing now will not stop even if we keep emissions at current levels," Koziell told CBS News, but she added that "all hope is not lost."

"If we commit to decarbonisation now, we still have an open window. We seriously need to keep that window open," Koziell said. "We need to seriously commit to reducing greenhouse gas emissions, and whatever investments we make now, will be a benefit for the future."

Himalayan glaciers could lose 80% of their volume if global warming isn't controlled, study finds


 A new report Tuesday, June 20, 2023, from a Nepal-based research organization finds that water security for nearly 2 billion people living downstream of rivers that originate in the Himalayan ranges will likely be threatened by the end of this century due to rapid glacier melt if global warming is not controlled. 

(AP Photo/Niranjan Shrestha, File)


SIBI ARASU
Mon, June 19, 2023 

BENGALURU, India (AP) — Glaciers are melting at unprecedented rates across the Hindu Kush Himalayan mountain ranges and could lose up to 80% of their volume this century if greenhouse gas emissions aren't sharply reduced, according to a report.

The report Tuesday from Kathmandu-based International Centre for Integrated Mountain Development warned that flash floods and avalanches would grow more likely in coming years, and that the availability of fresh water could be curtailed for nearly 2 billion people who live downstream of 12 rivers that originate in the mountains.

Ice and snow in the Hindu Kush Himalayan ranges are an important source of water for those rivers, which flow through 16 countries in Asia and provide fresh water to 240 million people in the mountains and another 1.65 billion downstream.

“The people living in these mountains who have contributed next to nothing to global warming are at high risk due to climate change,” said Amina Maharjan, a migration specialist and one of the report’s authors. “Current adaptation efforts are wholly insufficient, and we are extremely concerned that without greater support, these communities will be unable to cope.”

Various earlier reports have found that the cryosphere — regions on Earth covered by snow and ice — are among the worst affected by climate change. Recent research found that Mount Everest's glaciers, for example, have lost 2,000 years of ice in just the past 30 years.

“We map out for the first time the linkages between cryosphere change with water, ecosystems and society in this mountain region,” Maharjan said.

Among the key findings from Tuesday's report are that the Himalayan glaciers disappeared 65% faster since 2010 than in the previous decade, and that reducing snow cover due to global warming will result in reduced fresh water for people living downstream. The study found that 200 glacier lakes across these mountains are deemed dangerous, and the region could see a significant spike in glacial lake outburst floods by the end of the century.

The study found that communities in the mountain regions are being affected by climate change far more than many other parts of the world. It says changes to the glaciers, snow and permafrost of the Hindu Kush Himalayan region driven by global warming are “unprecedented and largely irreversible.”

Effects of climate change are already felt by Himalayan communities, sometimes acutely. Earlier this year the Indian mountain town of Joshimath began sinking and residents had to be relocated within days.

“Once ice melts in these regions, it's very difficult to put it back to its frozen form,” said Pam Pearson, director of the International Cryosphere Climate Initiative, who was not involved with the report.

She added, “It’s like a big ship in the ocean. Once the ice starts going, it’s very hard to stop. So, with glaciers, especially the big glaciers in the Himalayas, once they start losing mass, that’s going to continue for a really long time before it can stabilize.”

Pearson said it is extremely important for Earth's snow, permafrost and ice to limit warming to the 1.5 degrees Celsius agreed to at the 2015 Paris climate conference.

“I get the sense that most policymakers don't take the goal seriously but, in the cryosphere, irreversible changes are already happening," she said.

___

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AP PHOTOS: To save Alpine glaciers, 

Swiss team monitors the escalating melt

MATTHIAS SCHRADER

Wed, June 21, 2023 

GOMS, Switzerland (AP) — It is a sight in decline across Switzerland: glaciers sprawled across the Alps, formed over centuries of snow and sediment packed into a crystalline mass.

With the glaciers now dwindling at an alarming rate because of human-caused climate change, team members of the Swiss Federal Institute of Technology monitor what's left in an attempt to slow their demise.

Glaciologist Matthias Huss and his team use measuring and monitoring equipment to keep tabs on how much they've shrunk and desperately try to maintain their mass.

At the Rhone Glacier, one of the biggest in the Alps, workers prepare huge sheets to cover the ice like blankets in a bid to shield it from the warmth of the summer months.

Some stretches of mountain once covered with the grayish blue of glaciers are now mostly shrouded by white covers. Chunks of ice floating in a nearby lake are also conserved. The sheets are effective locally but are just a small-scale solution.

Alpine glaciers are still expected to vanish by the end of the century.

In the short term, glacier melt has meant more water, filling Alpine lakes and the flows for many of Europe's major rivers, giving some relief to those that rely on them amid Europe’s drought woes.

But there's also fear that the melting is causing glacier chunks to detach, sparking deadly avalanches.

In the longer term, the glaciers' disappearance would only add to the continent's water concerns.

Swiss glaciers experienced record melting last year, losing more than 6% of their volume and alarming scientists who say a loss of 2% would once have been considered extreme.

At the Aletsch glacier, the longest and deepest in the Alps and popular with tourists, small blue pools form where the snow has melted from the June heat. Water covers the tunnel that leads hikers to it.

But for those who travel to Aletsch, there's still enough of the glacier — for now — to make the journey worthwhile.

___

Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.

TO READ THE CUT LINES FOR THE PHOTOS GO TO

AP PHOTOS: To save Alpine glaciers, Swiss team monitors the escalating melt (yahoo.com)





















Chunks of ice covered by sheets float in a lake at the Rhone Glacier near Goms, Switzerland, Friday, June 16, 2023. The sheets are just a small scale solution and Alpine glaciers are still expected to vanish by the end of the century.

 (AP Photo/Matthias Schrader)

ASSOCIATED PRESS

Three of Mount Rainier's glaciers have melted away

Evan Bush
Thu, June 22, 2023

A warming climate has melted three glaciers on Mount Rainier, the tallest volcano in the lower 48 states — more evidence of the rapid worldwide decline of mountain ice.

The total mass of glacier ice on Mount Rainier, southeast of Seattle, is less than half what it was in 1896, according to estimates from a National Park Service report published this month. Among its more than two dozen glaciers, the mountain is likely to have lost an area of glacial ice that’s nearly the size of Manhattan. The pace of its losses is picking up, the report found.

“We’re getting to a tipping point on some of the south-facing glaciers. We’re reaching points where there’s really not a lot of ice to be lost,” said an author of the report, Scott Beason, a geologist at Mount Rainier National Park. “The area change is accelerating in the last six years. That’s kind of a big, scary thing.”

Mount Rainier’s glaciers are flowing rivers of ice at the headwater of five major watersheds in the Pacific Northwest. They provide drinking water downstream, feed mountain streams with cold water for salmon and spin hydropower turbines to generate electricity in the Northwest.

Glaciers across the world are on a path of prolonged decline, a trend driven by the human use of fossil fuels and the accumulation of heat-trapping gasses in the atmosphere, according to scientists who contributed to the United Nations Intergovernmental Panel on Climate Change. The near-simultaneous and ongoing retreat of nearly all of the world’s glaciers is unprecedented in at least the past 2,000 years, the panel found. The melting of glaciers is responsible for more than a fifth of global sea level rise.

Mount Rainier on Sept. 27, 2022. (Planet Labs PBC)

Declines in the ice stored around Rainier’s cap could reduce habitat for fish like bull trout, which the U.S. Fish & Wildlife Service categorizes as a threatened species. The retreat of glaciers has already caused structures at Camp Muir, a camp for climbers, to shift slightly as the ground destabilizes, Beason said. Further declines could cause more debris flows and landslides as the retreat of glaciers reshapes the park’s landscape.

“It’s going to turn into a darker-looking mountain,” Beason said. “Everything is going to look different in the next century because of this. It will be interesting to see how we adapt.”

Mountain glaciers are a water source for nearly 2 billion people. A study published this year in the journal Science predicts mountain glaciers will lose 26% to 41% percent of their mass, as measured in 2015, by the end of this century depending on how much more the Earth warms.

Mount Rainier is the most glaciated peak in the lower 48 states, and its slopes contain more ice than all of the glaciers that blanket the rest of the peaks in Cascade Range mountains combined, Beason said.

The mountain’s summit is about 60 miles from Seattle, and it dominates the city’s skyline on clear days. It draws more than 2 million visitors every year. For much of the year, its glaciers are blanketed in fresh snow. Glacier ice is exposed in the summer as the snow melts away.

The park’s glaciers — defined as moving bodies of ice that persist — have been mapped for 125 years, with a first inventory completed in 1896, according to the report on Mount Rainier’s glaciers, which summarized centuries of research on the extent of glaciers in the national park.

The report, which listed 28 glaciers for 2021, found their mass decreased by nearly 52% since 1896. The area of Mount Rainier covered by glaciers fell from nearly 50 square miles to just more than 29 square miles — a nearly 42% decline.

The National Park Service officially removed the Stevens Glacier from its inventory because it had grown too small and there was a lack of evidence that ice was flowing, such as crevassing.

The report said two other glaciers — the Pyramid and Van Trump glaciers — lost 34% and 43% of their volume from 2015 to 2021. Park researchers concluded they were “in serious peril.”

Mount Rainier in 2020. (Evan Bush / NBC News)

Mauri Pelto, an environmental scientist and professor at Nichols College in Massachusetts who has monitored glaciers in the Cascades since the early 1980s, separately examined more recent satellite data from 2022 and found both the Pyramid and Van Trump glaciers were too fragmented and small to be considered glaciers. He called it a “dramatic change” since 2015.

“There’s just a few ice patches the size of a Little League field,” said Pelto, who considers both to be dead glaciers.

Beason said that the park’s study evaluated conditions only through 2021 but that he didn’t doubt Pelto’s independent assessment.

The melt-out leaves the park with just 26 glaciers. The three dead glaciers join a list of icy features now gone from Mount Rainier, including the Paradise ice caves, which disappeared in the 1980s, and the Williwakas Glacier, which was considered dead in the 1930s.

“We need to be real about what’s happening,” Pelto said. “Let’s not let them slip away and not acknowledge that they’re gone.”

WHO prepares for El Nino-linked spread of viral disease



Reuters
Wed, June 21, 2023

(Reuters) - The World Health Organization is preparing for an increased spread of viral diseases like dengue, Zika and chikungunya linked to the El Nino weather phenomenon, the agency's director general Tedros Adhanom Ghebreyesus said on Wednesday.

El Nino, a warming of water surface temperatures in the eastern and central Pacific Ocean, has officially returned after three years of the La Nina climate pattern. This is likely to yield extreme weather later this year, from tropical cyclones spinning toward vulnerable Pacific islands to heavy rainfall in South America to drought in Australia and in some parts of Asia.

"WHO is preparing for the very high probability that 2023 and 2024 will be marked by an El Nino event, which could increase transmission of dengue and other so called arboviruses, such as Zika and chikungunya," Ghebreyesus said.

The WHO chief also warned that climate change is fueling the breeding of mosquitoes, and incidence of dengue has already risen sharply in recent decades, particularly in the Americas.


Peru has declared a state of emergency in most regions this year and its health minister Rosa Gutierrez last week resigned amid a surge in cases of dengue. The disease is transmitted through the bites of aedes aegypti mosquitoes, with symptoms that include fever, eye, head, muscle and joint pain, nausea, vomiting and fatigue.

(Reporting by Leroy Leo in Bengaluru and Jennifer Rigby in London; editing by Frank Jack Daniel and Philippa Fletcher)

Study reveals how immune system of astronauts breaks down



 ISS photographed by Expedition 56 crew members from a Soyuz spacecraft after undocking

Wed, June 21, 2023 
By Will Dunham

WASHINGTON (Reuters) - Evidence is growing about the many ways that traveling in the microgravity environment of space tampers with the human body, with new research showing how it dials down the activity of genes in white blood cells crucial to the immune system.

A study involving 14 astronauts who spent 4-1/2 to 6-1/2 months aboard the International Space Station found that gene expression in these cells, also called leukocytes, quickly decreased when they reached space and then returned to normal not long after returning to Earth, researchers said on Thursday.

The findings offer insight into why astronauts are more susceptible to infections during flights, showing how the body's system for fighting off pathogens is weakened in space.

"A weaker immunity increases the risk of infectious diseases limiting astronauts' ability to perform their very demanding work in space. If an infection or an immune-related condition was to evolve to a severe state requiring medical care, astronauts while in space would have limited access to care and medication," said molecular biologist Odette Laneuville of the University of Ottawa in Canada, lead author of the research published in the journal Frontiers in Immunology.

Leukocytes are produced in the bone marrow and travel through the bloodstream and tissues. Once they detect bodily invaders like a virus or bacterium, they produce antibody proteins to attack the pathogen. Specific genes govern the release of such proteins.

The researchers examined leukocytes isolated in blood drawn from astronauts - 11 men and three women - from the Canadian Space Agency and U.S. space agency NASA, once before the flight, four times aboard the space station and five times after returning to Earth.

Gene expression in 247 genes in leukocytes was at about one third the normal levels while in space, the study found. This occurred within the first few days in space, but then remained at a stable level. The genes typically returned to normal behavior within about a month of an astronaut's return to Earth.

"White blood cells are very sensitive to the environment of space. They trade their specialized immune functions to take care of cell maintenance or housekeeping roles. Before this paper, we knew of immune dysfunction but not of the mechanisms," said study co-author Guy Trudel, an Ottawa Hospital rehabilitation medicine specialist.

Discovering altered gene behavior in leukocytes is "a significant step toward understanding human immune dysregulation in space," Trudel added.

This altered behavior, the researchers said, may result from a phenomenon called "fluid shift" in which blood in the absence of Earth's gravitational pull is redistributed from the lower to the upper part of the body. It is unlikely that greater solar radiation exposure in space was the culprit, they added.

"New and specific countermeasures will be needed," Trudel said.

Scientists previously documented astronauts experiencing immune dysfunction in space. This has included reactivation of latent viruses such as: Epstein-Barr, responsible for infectious mononucleosis; varicella-zoster, responsible for shingles; and herpes simplex 1, responsible for cold sores.

It also has been shown that astronauts in space shed more viral particles in their biological fluids - saliva and urine - increasing the risk of spreading pathogens to other astronauts whose own immune systems may be weakened.

The study, funded by the Canadian Space Agency, follows NASA-funded research published on June 8 that detailed brain changes in astronauts - expansion of spaces in the brain containing fluid that cushions it to protect against sudden impact and remove waste products.

Other documented effects of space travel include bone and muscle atrophy, cardiovascular changes, issues with the balance system in the inner ear and a syndrome involving the eyes. Cancer risk from greater radiation exposure is another concern.

(Reporting by Will Dunham, Editing by Rosalba O'Brien)

Probe captures stunning up-close views of Mercury's landscape



Kerry Breen
Wed, June 21, 2023 

A series of images taken by two satellites flying past Mercury captured multiple "tectonic and volcanic curiosities" as well as an impact crater on the planet.

The satellites, jointly named the BepiColombo mission, are operated by the European Space Agency and the Japan Aerospace Exploration Agency.

The photographs were taken during the mission's third gravity-assisted flyby at the planet, the ESA said in a news release. There will be six such flybys in total. The images were taken from 236 kilometers, or about 146 miles, above the planet's surface.

The black-and-white photos released by the agencies show multiple features, including the crater. The crater, newly named for Jamaican artist Edna Manley, is about 218 kilometers (135 miles) wide. Scientists found the crater to be of special interest because there appears to be "dark 'low reflectance material'" that researchers said in a news release might be remnants of the planet's early carbon-rich crust.

An annotated image showing the features photographed by BepiColombo. 

/ Credit: ESA/BepiColombo/MTM, CC BY-SA 3.0 IGO

The basin of the crater has been flooded with smooth lava, which researchers said is "demonstrative of Mercury's prolonged history of volcanic activity."


BepiColombo will continue monitoring the crater from orbit, measuring the carbon in the area and the minerals that may be inside it.

Two images taken closer to the planet show "one of the most spectacular geological thrust systems" on Mercury. The area is a "lobate scarp," a tectonic feature that researchers believe is formed by the planet cooling and contracting. As a result, the area looks wrinkled. There are also features in the area that have been flooded with volcanic lava.

"This is an incredible region for studying Mercury's tectonic history," says Valentina Galluzzi of Italy's National Institute for Astrophysics in the news release announcing the photos. "The complex interplay between these escarpments shows us that as the planet cooled and contracted it caused the surface crust to slip and slide, creating a variety of curious features that we will follow up in more detail once in orbit."

The mission will complete another flyby of Mercury in September 2024, researchers said.

NASA's Juno mission spots eerie green light on Jupiter: Here's what scientists think it is

Gabe Hauari, USA TODAY
Tue, June 20, 2023 

A NASA spacecraft spotted an eerie green light coming from Jupiter.

The light is believed to be the glow from a bolt of lightning near the planet's north pole.

Unlike Earth, where lightning bolts originate from water clouds and happen most frequently near the equator, lightning on Jupiter occurs in clouds containing an ammonia-water solution, and most often occurs near the poles, according to NASA.

The photo was released Thursday after being captured by NASA's Juno mission as it completed its 31st close flyby of Jupiter on Dec. 30, 2020. The spacecraft was about 19,000 miles above Jupiter's cloud tops when the image was taken.

Aliens among us? Vegas UFO report latest in UAP sightings investigated worldwide

A NASA spacecraft spotted a green light coming from Jupiter.

According to NASA, the Juno mission spacecraft began its five-year journey to explore Jupiter in August 2011 and first arrived on the planet in July 2016. Now in its extended mission, the spacecraft will continue to explore the planet until September 2025, or until the spacecraft's end of life.

This article originally appeared on USA TODAY: Lightning on Jupiter: NASA releases Juno mission photo of green light

The expansion of the universe could be a mirage, new theoretical study suggests

Robert Lea
Wed, June 21, 2023 

a cloud of blue-white gas in space

The expansion of the universe could be a mirage, a potentially controversial new study suggests.

This rethinking of the cosmos also suggests solutions for the puzzles of dark energy and dark matter, which scientists believe account for around 95% of the total energy and matter in the universe but remain shrouded in mystery.

The novel new approach is detailed in a paper published June 2 in the journal Classical and Quantum Gravity, by University of Geneva professor of theoretical physics Lucas Lombriser.

Related: Our expanding universe: Age, history & other facts

Scientists know the universe is expanding because of redshift, the stretching of light's wavelength towards the redder end of the spectrum as the object emitting it moves away from us. Distant galaxies have a higher redshift than those nearer to us, suggesting those galaxies are moving ever further from Earth.

More recently, scientists have found evidence that the universe's expansion isn't fixed, but is actually accelerating faster and faster. This accelerating expansion is captured by a term known as the cosmological constant, or lambda.

The cosmological constant has been a headache for cosmologists because predictions of its value made by particle physics differ from actual observations by 120 orders of magnitude. The cosmological constant has therefore been described as "the worst prediction in the history of physics."

Cosmologists often try to resolve the discrepancy between the different values of lambda by proposing new particles or physical forces but Lombriser tackles it by reconceptualizing what's already there.

"In this work, we put on a new pair of glasses to look at the cosmos and its unsolved puzzles by performing a mathematical transformation of the physical laws that govern it," Lombriser told Live Science via email.

In Lombriser's mathematical interpretation, the universe isn't expanding but is flat and static, as Einstein once believed. The effects we observe that point to expansion are instead explained by the evolution of the masses of particles — such as protons and electrons — over time.

In this picture, these particles arise from a field that permeates space-time. The cosmological constant is set by the field's mass and because this field fluctuates, the masses of the particles it gives birth to also fluctuate. The cosmological constant still varies with time, but in this model that variation is due to changing particle mass over time, not the expansion of the universe.

In the model, these field fluctuations result in larger redshifts for distant galaxy clusters than traditional cosmological models predict. And so, the cosmological constant remains true to the model's predictions.

"I was surprised that the cosmological constant problem simply seems to disappear in this new perspective on the cosmos," Lombriser said.
A recipe for the dark universe

Lombriser's new framework also tackles some of cosmology's other pressing problems, including the nature of dark matter. This invisible material outnumbers ordinary matter particles by a ratio of 5 to 1, but remains mysterious because it doesn't interact with light.

Lombriser suggested that fluctuations in the field could also behave like a so-called axion field, with axions being hypothetical particles that are one of the suggested candidates for dark matter.

These fluctuations could also do away with dark energy, the hypothetical force stretching the fabric of space and thus driving galaxies apart faster and faster. In this model, the effect of dark energy, according to Lombriser, would be explained by particle masses taking a different evolutionary path at later times in the universe.

In this picture "there is, in principle, no need for dark energy," Lombriser added.

RELATED STORIES:

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Post-doctoral researcher at the Universidad ECCI, Bogotá, Colombia, Luz Ángela García, was impressed with Lombriser's new interpretation and how many problems it resolves.

"The paper is pretty interesting, and it provides an unusual outcome for multiple problems in cosmology," García, who was not involved in the research, told Live Science. "The theory provides an outlet for the current tensions in cosmology."

However, García urged caution in assessing the paper's findings, saying it contains elements in its theoretical model that likely can't be tested observationally, at least in the near future.

Originally published on LiveScience.com.

SPACE NEWS

A violent collision likely created the Geminids meteor shower

CNN
Wed, June 21, 2023 

The Geminid meteor shower, which lights up the sky each December, is one of the most active and dependable celestial displays of the year.

But the actual origin of the winter light show is something of a mystery. Now, astronomers using NASA’s Parker Solar Probe have gained more insight into the underlying cause of the Geminids.

The meteor shower was first recorded in 1862 and appears to radiate from the Gemini constellation. During the meteor shower’s peak in mid-December, 120 bright yellow meteors can be seen per hour if skies are clear.

Meteors typically originate from the leftover bits and pieces of comets orbiting around the sun. When comets, which originate in the icy outskirts of the solar system, pass close to the sun, they shed trails of particles. Meteor showers appear in Earth’s skies when our planet passes through the debris trails. As the particles collide with Earth’s atmosphere, they blaze up and disintegrate, leaving fiery streaks behind, according to NASA.


The Geminids, however, are unusual in that they have been traced to the asteroid 3200 Phaethon. Scientists have debated the very nature of what Phaethon is. It’s possible that Phaethon is a “dead comet,” with an icy shell that eventually melted away. The closely tracked near-Earth asteroid has been likened to comets, so it’s been called a “rock comet.”

“What’s really weird is that we know that Phaethon is an asteroid, but as it flies by the Sun, it seems to have some kind of temperature-driven activity. Most asteroids don’t do that,” said Jamey Szalay, a research scientist at Princeton University, in a statement. Szalay is the coauthor of a study about the asteroid published on June 15 in The Planetary Science Journal.

Although the Parker Solar Probe, launched in 2018, is on a mission to “touch” and study the sun, the spacecraft’s increasingly close proximity to our star is useful for scientists wanting to study the dust swirling around the inner solar system. The probe’s instruments have provided scientists with a detailed view of the dust particles shed by comets and asteroids on their treks around the sun — and in doing so shed new light on the Geminids-Phaethon connection.
How an asteroid sparked a meteor shower

While the spacecraft doesn’t actually carry a dust counting instrument to measure the grains, the particles impact the Parker Solar Probe as it orbits the sun. As dust hits the spacecraft, it creates electrical signals that can be picked up by the probe’s instruments, including one that measures electric and magnetic fields near the sun.

The Geminid meteor shower streaks across the night sky over the Lhasa River in Tibet on December 14, 2022. - Jiang Feibo/China News Service/VCG/Getty Images

Data collected by the Parker Solar Probe was used by scientists to model three different scenarios for the Geminid meteor shower, which were then compared with models based on observations from Earth.

The data revealed that the most probable cause of the meteor shower was a sudden, violent event, likely a rapid collision of the asteroid with another space rock or even some kind of gaseous explosion that caused the Geminids to first appear in our skies in 1862.

Phaethon was discovered on October 11, 1983, by astronomers using the Infrared Astronomical Satellite.

After Phaethon’s discovery, astronomer Fred Whipple realized that the asteroid and the Geminid meteor shower stream had nearly identical orbits, and he made a connection between the two.

It’s the first asteroid to be associated with a meteor shower, and it measures about 3.17 miles (5.10 kilometers) across. Astronomers have studied the space rock for years in an attempt to determine why it behaves like a comet.

The space rock was named after the Greek myth about the son of Helios, the sun god, because it closely approaches our sun.

Phaethon orbits the sun closer than any other asteroid and takes 1.4 years to complete its orbit.

Even before studying dust in our solar system with Parker Solar Probe, astronomers determined that the asteroid heats up to about 1,300 degrees Fahrenheit (704 degrees Celsius) on its closest approach to the sun, which causes Phaethon to shed more dusty debris.

These particles cause the meteor shower each year when they plunge into Earth’s atmosphere at 79,000 miles per hour (127,000 kilometers per hour), vaporizing in the streaks we call “shooting stars.”

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Watch sunlight dance across Earth from solstice to solstice in this gorgeous video

Tereza Pultarova

SPACE
Wed, June 21, 2023 a

a shadow moves across the face of the Earth

An amazing new video demonstrates how Earth's tilt changes throughout the year, causing days to lengthen and shorten from north to south as the planet orbits the sun.

The Northern Hemisphere is experiencing the longest day of the year as our planet reached the moment of the summer solstice today, June 21, at 10:57 a.m. EDT (1457 GMT).

The summer solstice is the moment when the Earth's Northern Hemisphere is most tilted toward the sun, therefore receiving the maximum amount of sunlight during the day. That means the day is the longest for the half of the planet north of the equator where the summer season is entering its peak.


Related: Stonehenge's summer solstice orientation is seen in monuments all over the UK in amazing photos

an illustration depicting how the Earth's tilt affects the seasons

But while the Northern Hemisphere is basking in sunshine, the Southern Hemisphere is trudging through its darkest day of culminating winter. From tomorrow on, the Southern Hemisphere's day will begin to lengthen while the Northern Hemisphere will start losing minutes of daylight.

The new video above released by Simon Proud, an Earth-observation scientist at the National Center for Earth Observation in the U.K., shows the terminator line, the boundary between the day and night, as it moves throughout the year.

"This video, using @eumetsat weather satellite data, shows how the sun appears to move during the year: It is made using 365 pictures, all taken at 6 a.m. on each day over the past year," Proud said in a tweet.

As we know, the sun doesn't really move across the sky (even though it does orbit the center of our galaxy the Milky Way). Its apparent motion overhead is caused by the Earth's rotation around its tilted axes, which means the arc the sun draws in the sky changes day by day, growing larger in the Northern Hemisphere from the winter solstice in December to the summer solstice in June and vice versa.

Related stories:

— June Solstice 2023: How twilight zones affect day length

— The summer solstice: When is it and when does it occur? — What is an equinox?

The video is a sequence of images taken by the European weather satellite Meteosat, which observes the planet from its perch in the geostationary orbit, an orbit at an altitude of 22,200 miles (36,000 kilometers), where spacecraft appear suspended above a fixed spot above Earth's equator.

The planet is now beginning its move toward the autumn equinox, which takes place in September and which sees both hemispheres receiving an equal amount of sunshine on that given day.

The Milky Way's monster black hole let out a huge blast 200 years ago. We can now listen to its echo (video)


Keith Cooper

SPACE
Wed, June 21, 202

purple clouds of gas in space

The supermassive black hole at the center of our Milky Way galaxy woke up and unleashed a fierce outburst of X-rays around the turn of the 19th century, according to new observations of the 'echoes' of the event.

Astronomers have noticed that immense clouds of star-forming molecular gas that inhabit the central region of the Milky Way galaxy shine brighter in X-rays than expected. One possible explanation put forward was that this X-ray light was not intrinsic to the gas clouds, but was being reflected off of them following an outburst from the black hole, which is named Sagittarius A* (Sgr A*) and has a mass 4.1 million times that of our sun.

The theory is that, sometime in the relatively recent past, the Sagittarius A* devoured something in just this fashion, and the flash of X-rays is being reflected by the molecular gas clouds in the vicinity of the black hole. Now, a team led by Frédéric Marin of the University of Strasbourg has used NASA's Imaging X-ray Polarimetry Explorer (IXPE) satellite has not only found strong evidence that this was the case, but has also been able to put an approximate date on when it happened.


Related: Sagittarius A*: The Milky Way's supermassive black hole

an orange ring on a black background

The gravitational tidal forces around a black hole as massive as Sagittarius A* are strong enough to rip apart anything that wanders too close in a frenzied act of violence. This process releases a flare of X-rays as a gas cloud, a star or even an asteroid is torn asunder, and the debris forms a hot disc of material that spirals into the black hole's maw.

NASA's IXPE spacecraft can measure the polarization of X-ray light from such events. Polarization refers to light waves oscillating in a preferred direction, which can reveal information about how the light has been produced and reflected. IXPE found that the X-ray echoes have a polarization angle consistent with an origin in the direction of Sagittarius A*. Furthermore, the strength of the polarization indicates that the X-rays were emitted a little over 200 years ago in an event that lasted less than a year-and-a-half.

clouds of purple gas in space

"Our work presents the missing piece of evidence that X-rays from the giant molecular clouds are due to reflection of an intense, yet short-lived flare produced at or nearby Sgr A*," Marin's team wrote in a paper describing their findings.

The brightness of the X-ray echoes indicates that this outburst increased the black hole's X-ray luminosity a millionfold compared to its dormant state today. The total amount of energy released is estimated to be between 1039 – 1044 ergs. This is comparable with a breed of active galaxy called a Seyfert, which have supermassive black holes that feeding on large amounts of material but over a much longer period of time.

RELATED STORIES:

— Brilliant gamma-ray flare 100 times brighter than our entire galaxy reveals 1 monster black hole is actually 2

— The loneliest monster black holes may also be the hungriest

— Sagittarius A* in pictures: The 1st photo of the Milky Way's monster black hole explained in images

Exactly what unfortunate object fell too close to Sagittarius A* to be ripped apart remains unknown. The existence of stars that orbit very close to the black hole, and clouds of gas that pass dangerously close and are distorted by the black hole's gravity, suggest that there is a ready supply of material that will eventually fall into the black hole.

The findings were published on June 21 in the journal Nature.

Sun unleashes giant X-flare in outburst that could spark auroras on Mars (video)

Elizabeth Howell
Wed, June 21, 2023 

a close-up of the sun in false color wavelengths, with a burst of flare on the left limb

Behold the power of the sun!

Our star unleashed an X-flare — the strongest type of solar radiation outburst — at 1:09 p.m. EDT (1709 GMT) on Tuesday (June 20).

Footage of the flare was caught by NASA's Solar Dynamics Observatory, which keeps a constant watch on sun activity alongside other agency satellites and observatories from the European Space Agency, among other entities.

Related: Space weather: What is it and how is it predicted?

NASA Solar Dynamics Observatory captured the newly arrived sunspot AR3341 blasting out a powerful X1.1 solar flare on June 20, 2023. (Image credit: NASA/SDO)

"Solar flares are powerful bursts of radiation," NASA's sun account on Twitter stated. "Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground. However — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel."

The flare was associated with a coronal mass ejection (CME), a huge cloud of superheated plasma that the sun blasted into space. The CME was not aimed at Earth and, as such, it will not ramp up any auroral displays here, according to SpaceWeather.com, citing a NASA model.

But the solar plasma may spark a glowing light show on Mars that will be visible in a few days to orbiters there, such as NASA's Mars Atmosphere and Volatile Evolution (MAVEN).

RELATED STORIES:

— How hot is the sun?

— How was the sun formed?

— See amazing new sun photos from the world's largest solar telescope

The sun is currently nearing the peak of its 11-year activity cycle, with many sunspots clustering on the surface. Sunspots — hotbeds of magnetic activity — serve as launch pads for flares and CMES.

Normally, these eruptions are harmless to humanity, causing only light shows. But NASA and other agencies keep an eye on the sun just in case a warning is required to protect essential infrastructure, like power lines or satellites.

Why didn't the infant universe collapse into a black hole?

Paul Sutter
Wed, June 21, 2023 

spindly purple swirls in deep space, representing star formation in the early universe

You may have wondered: Why didn't the universe collapse into a black hole during the earliest moments of the Big Bang? Simply put, because that's not how you make a black hole.

If you want to make a black hole yourself, it's relatively straightforward: You just take any object and squeeze it as hard as possible. If you can resist all of the other forces and squeeze any amount of matter below a certain critical threshold, then gravity will take over and do the rest of the work for you, crunching that matter down into an infinitely small point and creating a black hole.

That threshold, known as the Schwarzschild radius, depends on the amount of matter you want to squeeze. If you were to take a human body and squeeze it down to the size of roughly an atomic nucleus, you would end up with a human-mass black hole the width of an atomic nucleus. If you were to repeat the process with our planet, you would end up with an Earth-mass but bean-sized black hole.

Related: What happens at the center of a black hole?

Nature makes black holes all the time through the deaths of massive stars. When they run out of fuel, their own gravitational attraction pulls as much material as possible into as small a volume as possible, eventually overwhelming any other force of nature and creating black holes a few miles across with the mass of a few suns.

So that's the simple, one-step trick to making black holes: You take a lot of matter and squeeze it to incredibly high densities.
The early universe

But the centers of massive stars are not the only locales in the universe that have reached incredibly high densities. About 13.77 billion years ago, our entire visible universe was crammed into a volume no bigger than a peach with a temperature of over a quadrillion degrees. That's a rather high density.

So why didn't the entire universe collapse into a black hole? There are two reasons.

One, the creation of a black hole relies on not only incredibly high densities but also density differences. To make a black hole, you need a lot of material crammed into a very small volume, with nothing else surrounding it. Gravity works only on differences. If the density is the same from place to place, then there are no gravitational differences and thus no chance to trigger the formation of a black hole.

Yes, the early universe was incredibly dense. But it was dense everywhere, with barely any differences. Without those differences, black holes couldn't form, because there was no difference in gravity that could lead to the sudden collapse of matter.

RELATED STORIES:

— Could the universe collapse into a singularity? New study explains how.

— Are there any black holes left over from the Big Bang?

— Tiny primordial black holes could have created their own Big Bang
A dynamic universe

But even without density differences, what about the entire universe recollapsing into the singularity that birthed the Big Bang itself? Just to be clear, that wouldn't make the universe turn into a black hole. A black hole is an ultradense collection of matter within space. When we're talking about the expansion or contraction of the universe, we're talking about the evolution of space itself.

But even if it wasn't a black hole, what prevented the collapse into a singularity? What prevented it is that the early universe wasn't static — it was dynamic. It was evolving. It was changing. And most importantly, it was expanding.

The rules of black hole formation simply don't apply in an expanding universe. It's no longer like a star sitting in the middle of empty space, imploding on itself. To collapse into a singularity, it's not enough to have a ton of mass sitting around. You need an overwhelming amount of mass to counteract the natural expansion of the universe and force it to collapse.

And there simply wasn't enough mass in the universe to do that — back then and even now. For decades, cosmologists wondered if there might be enough matter in the universe to cause the present-day expansion to slow down, stop and reverse, eventually leading to a "big crunch" and a return to a singularity.

But multiple measurements have confirmed that there isn't enough stuff to get the job done. Our universe will, as far as we can tell, continue expanding well into the future. Which is a good thing for us — life as we know it doesn't tend to do well inside black holes.