CNN
World’s biggest iceberg, A23a, has broken up
Lianne Kolirin and Issy Ronald, CNN
Wed, September 3, 2025 at 9:37 AM CDT
The world’s largest iceberg is “rapidly breaking up” into several large “very large chunks,” scientists from the British Antarctic Survey (BAS) have said.
Previously weighing nearly a trillion metric tonnes (1.1 trillion tons) and spanning an area of 3,672 square kilometers (1,418 square miles) — slightly bigger than Rhode Island — the A23a iceberg has been closely tracked by scientists ever since it calved from the Filchner-Ronne ice shelf in Antarctica in 1986.
A23a has held the “largest current iceberg” title several times since the 1980s, occasionally being surpassed by larger but shorter-lived icebergs, including A68 in 2017 and A76 in 2021.
Andrew Meijers, an oceanographer at BAS, told CNN in an email Wednesday: “The iceberg is rapidly breaking up, and shedding very large chunks, themselves designated large icebergs by the US national ice centre that tracks these.”
The “megaberg” has now shrunk to about 1,700 square kilometers (656 square miles), according to Meijers, which equates to roughly the size of Greater London.
A23a remained grounded on the Antarctic’s Weddell Sea floor for more than 30 years, probably until it shrank just enough to loosen its grip on the seafloor.
Then in 2020, it was carried away by ocean currents before it became stuck again in a Taylor column — the name given to a spinning vortex of water caused by ocean currents hitting an underwater mountain — until it was reported to be on the move again last December. In March this year it ran aground on a continental shelf before floating loose again in May.
Meijers explained the circumstances that led to the iceberg’s breakup. “It has been following the strong current jet known as the Southern Antarctic Circumpolar Current Front (SACCF) anti-clockwise around South Georgia ever since it floated loose in May, after grounding on the continental shelf for a few months in March.
He said A23a is “following a similar fate” to other megabergs, such as A68 in 2021 and A76 in 2023, which also disintegrated around South Georgia, a British Overseas Territory in the southern Atlantic Ocean, though it has stayed in one piece for longer than either of those.
The disintegration means the crown for world’s largest iceberg is now held by D15a, which measures around 3,000 square kilometers (1,158 square miles) and, according to Meijers, is “fairly static on the Antarctic coast near the Australian Davis base.”
A23a currently still holds the title of the world’s second-largest iceberg, but Meijers said this is likely to “rapidly change” as it continues to “fragment in the coming weeks.” Warmer water temperature and the onset of southern spring means it will probably break into “bergs too small to track further,” he said.
Iceberg calving is a natural process and there haven’t been enough megabergs for scientists to know if they are increasing as the world warms, Meijers said. What is clear, however, is that ice shelves have lost trillions of tons of ice through increased iceberg formation and melting over the past few decades, much of which is due to warming ocean water and changes in ocean currents, he added.
Human-caused climate change is driving alarming changes in Antarctica, which could lock in catastrophic sea level rise.
Scientists onboard BAS polar research ship the RRS Sir David Attenborough visited the A23a while it was grounded on the South Georgia shelf. Samples taken have recently returned to the UK for analysis, a BAS spokesperson told CNN.
“The grounding and enormous release of cold freshwater are likely to have had a major impact on organisms on the seabed and in the surrounding water,” the spokesperson said, adding: “It is important to understand these impacts as large icebergs may become a more common feature at South Georgia as a result of global warming.”
CNN’s Laura Paddison contributed to this report.
https://currently.att.yahoo.com/news/ar ... 10437.html
Articles of Interest in Science
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swamidada786
- Posts: 250
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Re: Articles of Interest in Science
GEEKSPIN
NASA confirms Earth now has two moons until 2083
Discovered this year but traveling with us since the 1960s, the small asteroid will drift away in 2083
Stefan Milovanovic
Mon, October 20, 2025 at 4:39 PM CDT·
Earth just got a new tag-along in space — a little asteroid named 2025 PN7.
NASA confirmed this week that the rock, discovered by the University of Hawaii, is officially a “quasi-moon” — a rare type of celestial companion that travels almost exactly in sync with Earth. So it’s not a true moon, but it keeps pace with us, looping around the Sun in a path so similar that it appears to shadow our planet as we orbit.
Scientists estimate it’s only 18 to 36 meters wide, about the height of a small building. Tiny by cosmic standards, but significant enough to earn its own place in Earth’s extended neighborhood.
Unlike the Moon, which is held tight by gravity, this asteroid isn’t bound to us. Think of it more like a friendly runner matching your stride on the same track — close enough to notice, but never touching.
Astronomers say 2025 PN7 has probably been tagging along for around 60 years, and if its current orbit holds, it’ll stay with us until 2083 before drifting away into open space again. At its closest, it comes within 4 million kilometers, roughly ten times farther than the Moon. At its most distant, it can swing out to 17 million. That constant ebb and pull comes from the competing gravity of the Sun and neighboring planets.
Finding it wasn’t easy. The University of Hawaii team first spotted the object during a routine telescope survey earlier this year. What looked like a faint speck moving against the stars turned out to be following Earth’s exact pace around the Sun. After weeks of observation, NASA confirmed what the data suggested — our planet had gained a temporary traveling partner.
So far, astronomers have confirmed only eight quasi-moons in total, making each one a small but valuable clue in understanding how asteroids move and how Earth’s gravity shapes the space around us.
For scientists, these objects are more than curiosities. They help refine orbital models, improve predictions for near-Earth asteroids, and could one day serve as easy testing grounds for future missions. They’re close, relatively stable, and — unlike most deep-space targets — reachable without straying too far from home.
No, 2025 PN7 won’t ever outshine the real Moon. But it’s there and worth knowing about — a silent traveler keeping pace with us, orbit after orbit, as Earth continues its endless lap around the Sun.
https://currently.att.yahoo.com/news/ar ... 56357.html
NASA confirms Earth now has two moons until 2083
Discovered this year but traveling with us since the 1960s, the small asteroid will drift away in 2083
Stefan Milovanovic
Mon, October 20, 2025 at 4:39 PM CDT·
Earth just got a new tag-along in space — a little asteroid named 2025 PN7.
NASA confirmed this week that the rock, discovered by the University of Hawaii, is officially a “quasi-moon” — a rare type of celestial companion that travels almost exactly in sync with Earth. So it’s not a true moon, but it keeps pace with us, looping around the Sun in a path so similar that it appears to shadow our planet as we orbit.
Scientists estimate it’s only 18 to 36 meters wide, about the height of a small building. Tiny by cosmic standards, but significant enough to earn its own place in Earth’s extended neighborhood.
Unlike the Moon, which is held tight by gravity, this asteroid isn’t bound to us. Think of it more like a friendly runner matching your stride on the same track — close enough to notice, but never touching.
Astronomers say 2025 PN7 has probably been tagging along for around 60 years, and if its current orbit holds, it’ll stay with us until 2083 before drifting away into open space again. At its closest, it comes within 4 million kilometers, roughly ten times farther than the Moon. At its most distant, it can swing out to 17 million. That constant ebb and pull comes from the competing gravity of the Sun and neighboring planets.
Finding it wasn’t easy. The University of Hawaii team first spotted the object during a routine telescope survey earlier this year. What looked like a faint speck moving against the stars turned out to be following Earth’s exact pace around the Sun. After weeks of observation, NASA confirmed what the data suggested — our planet had gained a temporary traveling partner.
So far, astronomers have confirmed only eight quasi-moons in total, making each one a small but valuable clue in understanding how asteroids move and how Earth’s gravity shapes the space around us.
For scientists, these objects are more than curiosities. They help refine orbital models, improve predictions for near-Earth asteroids, and could one day serve as easy testing grounds for future missions. They’re close, relatively stable, and — unlike most deep-space targets — reachable without straying too far from home.
No, 2025 PN7 won’t ever outshine the real Moon. But it’s there and worth knowing about — a silent traveler keeping pace with us, orbit after orbit, as Earth continues its endless lap around the Sun.
https://currently.att.yahoo.com/news/ar ... 56357.html
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swamidada786
- Posts: 250
- Joined: Tue Apr 29, 2025 8:56 pm
Re: Articles of Interest in Science
CNN
Scientists are racing to grow human teeth in the lab
Jacopo Prisco, CNN
Thu, October 23, 2025 at 8:18 PM CDT·
It’s not surprising that many people fear the dentist. Replacing a tooth often requires invasive surgery and implanting a titanium screw into a patient’s jawbone, then waiting months for that to strengthen into an artificial root, before attaching a crown or cap on top of it.
But research groups around the world are working to find ways to implant or grow real biological teeth in a human jaw.
That may be a way off, but at King’s College London, Ana Angelova Volponi, director of the postgraduate program in regenerative dentistry, has been experimenting with lab-grown teeth for almost two decades, and was part of a team that in 2013 grew a tooth from human and mouse cells.
This year, she led a study that built upon that work and achieved a breakthrough in the material used to house the growing tooth in the lab, which better mimics the actual environment where biological teeth grow in the mouth. It’s a key step on the way to replacing the mouse cells with human cells and stimulating them to form a tooth.
The idea of creating lab-grown teeth dates back to the 1980s, Volponi said, but the one that she and her colleagues created over a decade ago was the first that used adult human gingival cells — which make up the gums and are obtained by lightly scratching the inside of the mouth — and combined them with “progenitor” tooth cells taken from a mouse embryo.
“It’s almost like a tripod,” she said about the elements that contribute to growing a tooth in a lab setting. “The two types of cells are engaging in tooth making, in a sort of conversation, and then we have the environment where this happens.”
The environment, which researchers call a “scaffold,” is essential to the formation of the lab-grown tooth, and it’s the subject of Volponi’s most recent study. In 2013, Volponi used a scaffold made of the protein collagen, but now uses a hydrogel, a type of polymer with a high water content, explained Xuechen Zhang, a doctoral student at King’s College London, and a co-author of the study. “We gather the cells first from the mouse embryos and then mix them together and spin them down to get a small cell pellet,” he said. “Then we inject this cell pellet inside the hydrogel and grow it for around eight days.” Because the work focused on the environment, human cells aren’t needed.
At the end of the eight days, tooth-like structures will have formed inside the hydrogel, which was developed in collaboration with Imperial College London. In the 2013 research, these “tooth primordia” were transferred into a mouse where they developed into a tooth structure complete with developing roots and enamel.
Many challenges remain before a lab-grown tooth can be used in a human patient, but the new material helps with some pieces of that puzzle, Volponi said, by improving the “conversation” between the cells that are tasked with making a tooth.
Researchers still don’t know exactly how to replace the embryonic mouse cells with adult human cells, but if that puzzle is solved, Volponi envisions two possible ways to integrate lab-grown teeth into everyday dentistry: “We either grow a tooth up to a certain stage of development, and then embed it into the (tooth socket), where a lost tooth was and where the new one will have the potential to fully grow into a biological tooth, incorporating itself within the organic structures such as the bone and the ligament. Or, we fully grow the tooth first and then implant it surgically. It’s still too early to say which approach will be more viable.”
The advantages of real teeth
A real, biological replacement tooth grown from a patient’s own cells would offer many advantages over a crown or implant. First, it would be accepted into the tissue without inflammation or rejection, but it would also feel exactly like a real tooth — unlike implants that lack feeling and elasticity as they are simply fused into the bone.
According to Vitor C. M. Neves, a senior clinical lecturer at the School of Clinical Dentistry of the University of Sheffield in England, Volponi has long been a pioneer in the field of whole tooth regeneration, serving as an inspiration to many researchers around the world. “Her new research tackles a key factor in the production and potential industrialization of this technology — the use of matrices in whole tooth regeneration,” said Neves, who was not involved with Volponi’s study.
The findings, he added, highlight the importance of creating an environment that can support whole tooth engineering for clinical application: “The more researchers who contribute to advancing this field, the sooner humanity will be able to reap its benefits.”
Other researchers working in the same field are using a variety of different techniques to grow teeth.
Katsu Takahashi and his colleagues at the Medical Research Institute Kitano Hospital in Osaka are developing an antibody-based treatment aimed at promoting the growth of teeth in people with conditions such as anodontia, or the congenital lack of teeth. The treatment has entered human clinical trials and could be ready by the end of the decade.
In late 2024, a team led by Pamela Yelick at the School of Dental Medicine of Tufts University, grew human-like teeth — created from human and pig cells — in pigs. Pigs, unlike humans, regrow their teeth several times over the course of their lives. The ultimate aim is to prompt cells in a human jaw to grow new teeth, without using any pig cells.
At the University of Washington, a team led by Hannele Ruohola-Baker, a professor of biochemistry and an associate director of the university’s Institute for Stem Cell and Regenerative Medicine, has successfully grown dental pulp stem cells from human stem cells mined from donated wisdom teeth: “We aim to uncover the molecular blueprint of human tooth formation and to recreate that process in the laboratory,” she said. “While Volponi’s study builds tooth-like structures from existing dental tissues, our platform generates the key human tooth-forming cell types (from scratch) and guides them along authentic developmental trajectories.”
As for when the fruits of all this research will become available, Ruohola-Baker believes we won’t have to wait that long. “Although clinical translation will take time, momentum in this field is accelerating, heralding a future in which biological tooth repair or replacement becomes a realistic option within the coming decade,” she said.
https://currently.att.yahoo.com/news/ar ... 42067.html
Scientists are racing to grow human teeth in the lab
Jacopo Prisco, CNN
Thu, October 23, 2025 at 8:18 PM CDT·
It’s not surprising that many people fear the dentist. Replacing a tooth often requires invasive surgery and implanting a titanium screw into a patient’s jawbone, then waiting months for that to strengthen into an artificial root, before attaching a crown or cap on top of it.
But research groups around the world are working to find ways to implant or grow real biological teeth in a human jaw.
That may be a way off, but at King’s College London, Ana Angelova Volponi, director of the postgraduate program in regenerative dentistry, has been experimenting with lab-grown teeth for almost two decades, and was part of a team that in 2013 grew a tooth from human and mouse cells.
This year, she led a study that built upon that work and achieved a breakthrough in the material used to house the growing tooth in the lab, which better mimics the actual environment where biological teeth grow in the mouth. It’s a key step on the way to replacing the mouse cells with human cells and stimulating them to form a tooth.
The idea of creating lab-grown teeth dates back to the 1980s, Volponi said, but the one that she and her colleagues created over a decade ago was the first that used adult human gingival cells — which make up the gums and are obtained by lightly scratching the inside of the mouth — and combined them with “progenitor” tooth cells taken from a mouse embryo.
“It’s almost like a tripod,” she said about the elements that contribute to growing a tooth in a lab setting. “The two types of cells are engaging in tooth making, in a sort of conversation, and then we have the environment where this happens.”
The environment, which researchers call a “scaffold,” is essential to the formation of the lab-grown tooth, and it’s the subject of Volponi’s most recent study. In 2013, Volponi used a scaffold made of the protein collagen, but now uses a hydrogel, a type of polymer with a high water content, explained Xuechen Zhang, a doctoral student at King’s College London, and a co-author of the study. “We gather the cells first from the mouse embryos and then mix them together and spin them down to get a small cell pellet,” he said. “Then we inject this cell pellet inside the hydrogel and grow it for around eight days.” Because the work focused on the environment, human cells aren’t needed.
At the end of the eight days, tooth-like structures will have formed inside the hydrogel, which was developed in collaboration with Imperial College London. In the 2013 research, these “tooth primordia” were transferred into a mouse where they developed into a tooth structure complete with developing roots and enamel.
Many challenges remain before a lab-grown tooth can be used in a human patient, but the new material helps with some pieces of that puzzle, Volponi said, by improving the “conversation” between the cells that are tasked with making a tooth.
Researchers still don’t know exactly how to replace the embryonic mouse cells with adult human cells, but if that puzzle is solved, Volponi envisions two possible ways to integrate lab-grown teeth into everyday dentistry: “We either grow a tooth up to a certain stage of development, and then embed it into the (tooth socket), where a lost tooth was and where the new one will have the potential to fully grow into a biological tooth, incorporating itself within the organic structures such as the bone and the ligament. Or, we fully grow the tooth first and then implant it surgically. It’s still too early to say which approach will be more viable.”
The advantages of real teeth
A real, biological replacement tooth grown from a patient’s own cells would offer many advantages over a crown or implant. First, it would be accepted into the tissue without inflammation or rejection, but it would also feel exactly like a real tooth — unlike implants that lack feeling and elasticity as they are simply fused into the bone.
According to Vitor C. M. Neves, a senior clinical lecturer at the School of Clinical Dentistry of the University of Sheffield in England, Volponi has long been a pioneer in the field of whole tooth regeneration, serving as an inspiration to many researchers around the world. “Her new research tackles a key factor in the production and potential industrialization of this technology — the use of matrices in whole tooth regeneration,” said Neves, who was not involved with Volponi’s study.
The findings, he added, highlight the importance of creating an environment that can support whole tooth engineering for clinical application: “The more researchers who contribute to advancing this field, the sooner humanity will be able to reap its benefits.”
Other researchers working in the same field are using a variety of different techniques to grow teeth.
Katsu Takahashi and his colleagues at the Medical Research Institute Kitano Hospital in Osaka are developing an antibody-based treatment aimed at promoting the growth of teeth in people with conditions such as anodontia, or the congenital lack of teeth. The treatment has entered human clinical trials and could be ready by the end of the decade.
In late 2024, a team led by Pamela Yelick at the School of Dental Medicine of Tufts University, grew human-like teeth — created from human and pig cells — in pigs. Pigs, unlike humans, regrow their teeth several times over the course of their lives. The ultimate aim is to prompt cells in a human jaw to grow new teeth, without using any pig cells.
At the University of Washington, a team led by Hannele Ruohola-Baker, a professor of biochemistry and an associate director of the university’s Institute for Stem Cell and Regenerative Medicine, has successfully grown dental pulp stem cells from human stem cells mined from donated wisdom teeth: “We aim to uncover the molecular blueprint of human tooth formation and to recreate that process in the laboratory,” she said. “While Volponi’s study builds tooth-like structures from existing dental tissues, our platform generates the key human tooth-forming cell types (from scratch) and guides them along authentic developmental trajectories.”
As for when the fruits of all this research will become available, Ruohola-Baker believes we won’t have to wait that long. “Although clinical translation will take time, momentum in this field is accelerating, heralding a future in which biological tooth repair or replacement becomes a realistic option within the coming decade,” she said.
https://currently.att.yahoo.com/news/ar ... 42067.html