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‘Finger-Like Solar Flares’ Explained in New Study

A solar flare is a term that denotes sudden flashes of brightness, caused by high-energy radiation, on the sun's surface. (Goddard Space Flight Center/AP)
A solar flare is a term that denotes sudden flashes of brightness, caused by high-energy radiation, on the sun's surface. (Goddard Space Flight Center/AP)
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‘Finger-Like Solar Flares’ Explained in New Study

A solar flare is a term that denotes sudden flashes of brightness, caused by high-energy radiation, on the sun's surface. (Goddard Space Flight Center/AP)
A solar flare is a term that denotes sudden flashes of brightness, caused by high-energy radiation, on the sun's surface. (Goddard Space Flight Center/AP)

In January 1999, scientists observed mysterious motions within a solar flare. Unlike typical flares that showed bright energy erupting outwards from the Sun, this solar flare also displayed a downward flow of motion, as if material was falling back towards the Sun. Astronomers wondered what exactly they were seeing.

Now, in a study published Jan. 27 in the journal Nature Astronomy, astronomers at the Center for Astrophysics | Harvard & Smithsonian (CfA) offer a new explanation for the poorly understood downflows.

"We wanted to know how these dark finger-like structures occur. What's driving them and are they truly tied to magnetic reconnection?" said lead author astronomer Chengcai Shen. Scientists have assumed that structures are tied to magnetic reconnection since their discovery in the 90s. The process occurs when magnetic fields break, releasing fast moving and extremely energetic radiation, and then reform.

"On the Sun, what happens is you have a lot of magnetic fields that are pointing in all different directions. Eventually the magnetic fields are pushed together to the point where they reconfigure and release a lot of energy in the form of a solar flare," said study co-author astronomer Kathy Reeves.

Reeves added: "It's like stretching out a rubber band and snipping it in the middle, so it's going to snap back."

Scientists assumed the dark downflows were signs of the broken magnetic fields "snapping back" to the Sun after a solar flare eruption. Most of the downflows observed by scientists are "puzzlingly slow." This is not predicted by classic reconnection models, which show the downflows should be much quicker. It's a conflict that requires some other explanation, said co-author Bin Chen, an astronomer at the New Jersey Institute of Technology.

To find out what was happening, the team analyzed downflow images captured by the Atmospheric Imaging Assembly (AIA) onboard NASA's Solar Dynamics Observatory. The AIA takes images of the Sun every 12 seconds in seven different wavelengths of light to measure variations in the Sun's atmosphere. They then made 3D simulations of solar flares and compared them to the observations.

The results show that most SADs are not generated by magnetic reconnection after all. Instead, they form on their own in the turbulent environment and are the result of two fluids with different densities interacting. Reeves said scientists are essentially seeing the same thing that happens when water and oil are mixed together: the two different fluid densities are unstable and ultimately separate. "Those dark, finger-like voids are actually an absence of plasma. The density is much lower there than the surrounding plasma," Reeves explained.

The team plans to continue their studies using 3D simulations to better understand magnetic reconnection. By understanding the processes that drive solar flares and eruptions from the Sun, they may ultimately help develop tools to forecast space weather and mitigate its impacts.

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Varieties

Coffee Regions Hit by Extra Days of Extreme Heat, Say Scientists 

17 April 2012, North Rhine-Westphalia, Vluyn: A general view of Arabica Coffee beans. (dpa)
17 April 2012, North Rhine-Westphalia, Vluyn: A general view of Arabica Coffee beans. (dpa)
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Coffee Regions Hit by Extra Days of Extreme Heat, Say Scientists 

17 April 2012, North Rhine-Westphalia, Vluyn: A general view of Arabica Coffee beans. (dpa)
17 April 2012, North Rhine-Westphalia, Vluyn: A general view of Arabica Coffee beans. (dpa)

The world's main coffee-growing regions are roasting under additional days of climate change-driven heat every year, threatening harvests and contributing to higher prices, researchers said Wednesday.

An analysis found that there were 47 extra days of harmful heat per year on average in 25 countries representing nearly all global coffee production between 2021 and 2025, according to independent research group Climate Central.

Brazil, Vietnam, Colombia, Ethiopia and Indonesia -- which supply 75 percent of the world's coffee -- experienced on average 57 additional days of temperatures exceeding the threshold of 30C.

"Climate change is coming for our coffee. Nearly every major coffee-producing country is now experiencing more days of extreme heat that can harm coffee plants, reduce yields, and affect quality," said Kristina Dahl, Climate Central's vice president for science.

"In time, these impacts may ripple outward from farms to consumers, right into the quality and cost of your daily brew," Dahl said in a statement.

US tariffs on imports from Brazil, which supplies a third of coffee consumed in the United States, contributed to higher prices this past year, Climate Central said.

But extreme weather in the world's coffee-growing regions is "at least partly to blame" for the recent surge in prices, it added.

Coffee cultivation needs optimal temperatures and rainfall to thrive.

Temperatures above 30C are "extremely harmful" to arabica coffee plants and "suboptimal" for the robusta variety, Climate Central said. Those two plant species produce the majority of the global coffee supply.

For its analysis, Climate Central estimated how many days each year would have stayed below 30C in a world without carbon pollution but instead exceeded that level in reality -- revealing the number of hot days added by climate change.

The last three years have been the hottest on record, according to climate monitors.

Varieties

Dog Gives Olympics Organizers Paws for Thought

A dog wanders on the ski trail during the women's team cross country free sprint qualification event of the Milano Cortina 2026 Winter Olympic Games at Tesero Cross-Country Skiing Stadium in Lago di Tesero (Val di Fiemme), on February 18, 2026. (Photo by Anne-Christine POUJOULAT / AFP)
A dog wanders on the ski trail during the women's team cross country free sprint qualification event of the Milano Cortina 2026 Winter Olympic Games at Tesero Cross-Country Skiing Stadium in Lago di Tesero (Val di Fiemme), on February 18, 2026. (Photo by Anne-Christine POUJOULAT / AFP)
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Dog Gives Olympics Organizers Paws for Thought

A dog wanders on the ski trail during the women's team cross country free sprint qualification event of the Milano Cortina 2026 Winter Olympic Games at Tesero Cross-Country Skiing Stadium in Lago di Tesero (Val di Fiemme), on February 18, 2026. (Photo by Anne-Christine POUJOULAT / AFP)
A dog wanders on the ski trail during the women's team cross country free sprint qualification event of the Milano Cortina 2026 Winter Olympic Games at Tesero Cross-Country Skiing Stadium in Lago di Tesero (Val di Fiemme), on February 18, 2026. (Photo by Anne-Christine POUJOULAT / AFP)

A dog decided he would bid for an unlikely Olympic medal on Wednesday as he joined the women's cross country team free sprint in the Milan-Cortina Games.

The dog ran onto the piste in Tesero in northern Italy and gamely, even without skis, ran behind two of the competitors, Greece's Konstantina Charalampidou and Tena Hadzic of Croatia.

He crossed the finishing line, his moment of glory curtailed as he was collared by the organizers and led away -- his owner no doubt will have a bone to pick with him when they are reunited.

Varieties

Olives, Opera and a Climate-Neutral Goal: How a Mural in Greece Won ‘Best in the World’ 

A building with the mural entitled “Kalamata” depicting opera legend Maria Callas by artist Kleomenis Kostopoulos is seen in Kalamata town, about 240 kilometers (150 miles) southwest of Athens, Monday, Feb. 9, 2026. (AP) 
A building with the mural entitled “Kalamata” depicting opera legend Maria Callas by artist Kleomenis Kostopoulos is seen in Kalamata town, about 240 kilometers (150 miles) southwest of Athens, Monday, Feb. 9, 2026. (AP) 
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Olives, Opera and a Climate-Neutral Goal: How a Mural in Greece Won ‘Best in the World’ 

A building with the mural entitled “Kalamata” depicting opera legend Maria Callas by artist Kleomenis Kostopoulos is seen in Kalamata town, about 240 kilometers (150 miles) southwest of Athens, Monday, Feb. 9, 2026. (AP) 
A building with the mural entitled “Kalamata” depicting opera legend Maria Callas by artist Kleomenis Kostopoulos is seen in Kalamata town, about 240 kilometers (150 miles) southwest of Athens, Monday, Feb. 9, 2026. (AP) 

Long known for its olives and seaside charm, the southern Greek city of Kalamata has found itself in the spotlight thanks to a towering mural that reimagines legendary soprano Maria Callas as an allegory for the city itself.

The massive artwork on the side of a prominent building in the city center has been named 2025’s “Best Mural of the World” by Street Art Cities, a global platform celebrating street art.

Residents of Kalamata, approximately 240 kilometers (150 miles) southwest of Athens, cultivate the world-renowned olives, figs and grapes that feature prominently on the mural.

That was precisely the point.

Vassilis Papaefstathiou, deputy mayor of strategic planning and climate neutrality, explained Kalamata is one of the few Greek cities with the ambitious goal of becoming climate-neutral by 2030. He and other city leaders wanted a way to make abstract concepts, including sustainable development, agri-food initiatives, and local economic growth, more tangible for the city’s nearly 73,000 residents.

That’s how the idea of a massive mural in a public space was born.

“We wanted it to reflect a very clear and distinct message of what sustainable development means for a regional city such as Kalamata,” Papaefstathiou said. “We wanted to create an image that combines the humble products of the land, such as olives and olive oil — which, let’s be honest, are famous all over the world and have put Kalamata on the map — with the high-level art.”

“By bringing together what is very elevated with ... the humbleness of the land, our aim was to empower the people and, in doing so, strengthen their identity. We want them to be proud to be Kalamatians.”

Southern Greece has faced heatwaves, droughts and wildfires in recent years, all of which affect the olive groves on which the region’s economy is hugely dependent.

The image chosen to represent the city was Maria Callas, widely hailed as one of the greatest opera singers of the 20th century and revered in Greece as a national cultural symbol. She may have been born in New York to Greek immigrant parents, but her father came from a village south of Kalamata. For locals, she is one of their own.

This connection is also reflected in practice: the alumni association at Kalamata’s music school is named for Callas, and the cultural center houses an exhibition dedicated to her, which includes letters from her personal archive.

Artist Kleomenis Kostopoulos, 52, said the mural “is not actually called ‘Maria Callas,’ but ‘Kalamata’ and my attempt was to paint Kalamata (the city) allegorically.”

Rather than portraying a stylized image of the diva, Kostopoulos said he aimed for a more grounded and human depiction. He incorporated elements that connect the people to their land: tree branches — which he considers the above-ground extension of roots — birds native to the area, and the well-known agricultural products.

“The dress I create on Maria Callas in ‘Kalamata’ is essentially all of this, all of this bloom, all of this fruition,” he said. “The blessed land that Kalamata itself has ... is where all of these elements of nature come from.”

Creating the mural was no small feat. Kostopoulos said it took around two weeks of actual work spread over a month due to bad weather. He primarily used brushes but also incorporated spray paint and a cherry-picker to reach all edges of the massive wall.

Papaefstathiou, the deputy mayor, said the mural has become a focal point.

“We believe this mural has helped us significantly in many ways, including in strengthening the city’s promotion as a tourist destination,” he said.

Beyond tourism, the mural has sparked conversations about art in public spaces. More building owners in Kalamata have already expressed interest in hosting murals.

“All of us — residents, and I personally — feel immense pride,” said tourism educator Dimitra Kourmouli.

Kostopoulos said he hopes the award will have a wider impact on the art community and make public art more visible in Greece.

“We see that such modern interventions in public space bring tremendous cultural, social, educational and economic benefits to a place,” he said. “These are good springboards to start nice conversations that I hope someday will happen in our country, as well.”