Category: 7. Science

The Permian-Triassic Mass Extinction – sometimes referred to as the “Great Dying,” happened around 252 million years ago, leading to the massive loss of marine species and significant declines in terrestrial plants and animals.

The event has been attributed to intense global warming triggered by a period of volcanic activity in Siberia, known as the Siberian Traps, but scientists have been unable to pinpoint why super-greenhouse conditions persisted for around five million years afterwards.

Now a team of international researchers led by the University of Leeds and the China University of Geosciences in Wuhan has gathered new data which supports the theory that the demise of tropical forests, and their slow recovery, limited carbon sequestration – a process where carbon dioxide is removed from the atmosphere and held in plants, soils or minerals.

During extensive field studies, the team used a new type of analysis of fossil records as well as clues about past climate conditions found in certain rock formations to reconstruct maps of changes in plant productivity during the Permian-Triassic Mass Extinction.

Their results, which are published on July 2 in Nature Communications,show that vegetation loss during the event led to greatly reduced levels of carbon sequestration resulting in a prolonged period where there were high levels of CO2.

The paper’s lead author, Dr Zhen Xu, from the School of Earth and Environment, University of Leeds, said: “The causes of such extreme warming during this event have been long discussed, as the level of warming is far beyond any other event.

“Critically, this is the only high temperature event in Earth’s history in which the tropical forest biosphere collapses, which drove our initial hypothesis. Now, after years of fieldwork, analysis and simulations, we finally have the data which supports it.”

The researchers believe their results reinforce the idea that thresholds, or ‘tipping points’ exist in Earth’s climate-carbon system which, when reached, means that warming can be amplified.

China is home to the most complete geological record of the Permian-Triassic mass Extinction and this work leverages an incredible archive of fossil data that has been gathered over decades by three generations of Chinese geologists.

The lead author Dr Zhen Xu is the youngest of these and is continuing the work begun by Professor Hongfu Yin and Professor Jianxin Yu, who are also authors of the study. Since 2016, Zhen and her colleagues have travelled throughout China from subtropical forests to deserts, including visiting areas accessible only by boat or on horseback.

Zhen came to the University of Leeds in 2020 to work with Professor Benjamin Mills on simulating the extinction event and assessing the climate impacts of the loss of tropical vegetation which is shown by the fossil record. Their results confirm that the change in carbon sequestration suggested by the fossils is consistent with the amount of warming that occurred afterwards.

Professor Mills added: “There is a warning here about the importance of Earth’s present day tropical forests. If rapid warming causes them to collapse in a similar manner, then we should not expect our climate to cool to preindustrial levels even if we stop emitting CO2.

“Indeed, warming could continue to accelerate in this case even if we reach zero human emissions. We will have fundamentally changed the carbon cycle in a way that can take geological timescales to recover, which has happened in Earth’s past.”

Reflecting on the study’s broader mission, Professor Hongfu Yin and Professor Jianxin Yu of the China University of Geosciences, underscored the urgency of blending tradition with innovation: “Paleontology needs to embrace new techniques — from numerical modelling to interdisciplinary collaboration — to decode the past and safeguard the future,” explained Professor Yin.

Professor Yu added: “Let’s make sure our work transcends academia: it is a responsibility to all life on Earth, today and beyond. Earth’s story is still being written, and we all have a role in shaping its next chapter.”

This research is primarily funded by the UK Research and Innovation (UKRI) and the National Natural Science Foundation of China (NSFC), with additional funding for collaborators provided by UKRI, ETH+, and the Australian Research Council. The work was conducted in collaboration with the following institutions:

• School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
• State Key Laboratory of Geomicrobiology and Environmental Changes, School of Earth Sciences, China University of Geosciences, Wuhan, 430074, P.R. China
• School of Physics, Chemistry and Earth Science, University of Adelaide, Adelaide, SA 5005, Australia
• Birmingham Institute of Forest Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
• Department of Biosystems Science and Engineering, ETH Zürich, Basel, 4056, Switzerland
• Computational Evolution Group, Swiss Institute of Bioinformatics, Lausanne, 1015, Switzerland
• State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, P.R. China
• Department of Biology, Howard University, Washington DC, USA
• Géosciences Environnement Toulouse, CNRS-Université de Toulouse III, Toulouse, France
• CEREGE, Aix Marseille Université, CNRS, IRD, INRA, Coll France, Aix-en-Provence, France

As winter gives way to spring, seasonal snowpack in the American West begins to melt.

Though some of that melt flows over and through shallow alpine soil, new research shows that much of it sinks into bedrock where it percolates for years before resurfacing. Fresh snowmelt makes up less than half of the water in the region’s gushing spring streams, according to the study.

The new finding could improve water resources forecasts. Hydrologic models, which inform the forecasts, largely overlook groundwater contributions and assume the spring’s heavy flows come directly from seasonal snowmelt.

The authors of the study, published in Communications Earth & Environment, used a radioactive isotope of hydrogen known as tritium to measure when the water in 42 western U.S. catchments fell as precipitation.

They found that during late winter, when rain and snowmelt were scarce and streams were fed primarily by groundwater, the water fell as precipitation an average of 10.4 years ago. Even during spring, when the same streams were overflowing with fresh runoff, their chilly waters had an average age of 5.7 years, still indicating significant contributions from groundwater.

A Subterranean Bucket

Hydrologic models typically simulate mountains as impermeable masses covered with a thin sponge of alpine soil, said the study’s first author, Paul Brooks, a hydrologist at the University of Utah. The sponge can absorb some water, but anything extra will quickly drain away.

“Snowmelt is being recharged into groundwater and is mobilizing groundwater that has been stored over much longer [periods].”

However, over the past few decades, scientists have uncovered a steady stream of hints that mountains may store huge volumes of water outside their spongy outer layer. Many high-elevation creeks carry dissolved minerals similar to those found in groundwater, suggesting a subterranean origin. Scientists studying healthy alpine ecosystems in arid conditions have wondered whether plants were tapping into a hidden reservoir of water.

Though snowmelt and rainfall immediately increase streamflow, the relationship is not intuitive. “What appears to be happening is that snowmelt is being recharged into groundwater and is mobilizing groundwater that has been stored over much longer [periods],” said James Kirchner, a hydrologist at Eidgenössische Technische Hochschule Zürich who was not involved in the research.

In areas where the mountains were made of porous sandstone, waters monitored in the new study were much older. In one such stream, the average age of water in winter was 14 years.

Mountains are “more like a bucket with a sponge on top.”

The authors were able to convincingly demonstrate the age of the flows because they used tritium, Kirchner said. Though scientists have previously used tritium to date water from individual streams and large bodies such as oceans and lakes, this study is the first to use tritium to date alpine groundwater and snowmelt across multiple catchments, Brooks said.

On the basis of historic flows, annual precipitation, and the ages of the stream water, the mountains could store an order of magnitude more water than accounted for in current models, Brooks said. As opposed to the impermeable masses in traditional models, he explained, mountains are “more like a bucket with a sponge on top.”

This finding could change how scientists think about the alpine water cycle. “If precipitation takes, on average, years to exit as streamflow, that means that streamflow in any one year is a function of years of climate and weather,” Brooks said. That means forecasters should consider more than just the most recent snowpack when estimating spring flows and potential flooding.

But further research is needed to unearth the role mountains play in water storage. The current study is limited because it covers only snowmelt-driven streams in the arid western United States, Kirchner said. Things might work differently in wetter places, he added.

—Mark DeGraff (@markr4nger.bsky.social), Science Writer

Citation: DeGraff, M. (2025), Years-old groundwater dominates spring mountain streams, Eos, 106, https://doi.org/10.1029/2025EO250238. Published on 3 July 2025.

Text © 2025. The authors. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

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Newswise — The Korea Research Institute of Standards and Science (KRISS, President Lee Ho Seong) has successfully developed a nanomaterial* capable of simultaneously performing cancer diagnosis, treatment, and immune response induction. Compared to conventional nanomaterials that only perform one function, this new material significantly enhances treatment efficiency and is expected to serve as a next-generation cancer therapy platform utilizing nanotechnology.
^{* Nanomaterial: Particles with a diameter between 1 and 100 nanometers (nm, 1 nm = one-billionth of a meter)}

Currently, cancer treatments primarily include surgery, radiation therapy, and chemotherapy. However, these treatments have significant limitations, as they not only affect cancerous areas but also cause damage to healthy tissues, leading to considerable side effects.

Cancer treatment using nanomaterials has emerged as a next-generation technology that aims to overcome the limitations of conventional treatments. By utilizing the physical and chemical properties of nanomaterials, it is possible to precisely target and deliver drugs to cancer cells and affected areas. Additionally, personalized treatments based on individual genetic profiles are now possible, offering a therapy that significantly reduces side effects while improving effectiveness compared to traditional methods.

The KRISS Nanobio Measurement Group has developed a new nanomaterial that not only allows real-time monitoring and treatment of cancerous areas but also activates the immune response system. The nanomaterial developed by the research team is a triple-layer nanodisk (AuFeAuNDs), with iron (Fe) inserted between gold (Au). The design of the nanomaterial, which features iron at the center of a disc-shaped structure, provides superior structural stability compared to traditional spherical materials. Additionally, by applying a magnet near the tumor site, the magnetic properties of the iron allow the nanomaterial to be easily attracted, further enhancing treatment efficiency.

The nanodisk developed by the research team is equipped with photoacoustic (PA) imaging capabilities, allowing for real-time observation of both the tumor’s location and the drug delivery process. PA is a technique that visualizes the vibrations (ultrasound) generated by heat when light (laser) is directed at the nanodisk. By using this feature, treatment can be performed at the optimal time when the nanomaterial reaches the tumor site, maximizing its effectiveness. In fact, in animal experiments, the research team successfully tracked the accumulation of nanoparticles at the tumor site over time using PA imaging, identifying that the most effective time for treatment is 6 hours after the material is administered.

Furthermore, this nanodisk can perform three different therapeutic mechanisms in an integrated manner, which is expected to treat various types of cancer cells, unlike materials that are limited to single therapies. While conventional nanomaterials used only photothermal therapy (PTT), which involves heating gold particles to eliminate cancer cells, the nanodisk developed by the research team can also perform chemical dynamic therapy (CDT) by utilizing the properties of iron to induce oxidation within the tumor, as well as ferroptosis therapy.

After treatment, the nanodisk also induces immune response substances. The developed nanodisk prompts cancer cells to release danger-associated molecular patterns (DAMPs) when they die, which helps the body recognize the same cancer cells and attack them if they recur. In animal experiments, the research team confirmed that the generation of warning signals through the nanodisk led to an increase in immune cell count by up to three times.

Dr. Lee Eun Sook stated, “Unlike conventional nanomaterials, which are composed of a single element and perform only one function, the material developed in this study utilizes the combined properties of gold and iron to perform multiple functions.”

This research was supported by the Ministry of Science and ICT’s ‘Next-Generation Advanced Nanomaterials Measurement Standard System Establishment Research Project’ and was published in February in Chemical Engineering Journal (Impact Factor: 13.4).

Here’s what you’ll learn when you read this story:

• One major division of the kingdom Animalia is Cnidarians (animals built around a central point) and bilaterians (animals with bilateral symmetry), which includes us humans.

• A new study found that the sea anemone, a member of the Cnidarian phylum, uses bilaterian-like techniques to form its body.

• This suggests that these techniques likely evolved before these two phyla separated evolutionarily some 600 to 700 million years ago, though it can’t be ruled out that these techniques evolved independently.

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Make a list of complex animals as distantly related to humans as possible, and sea anemones would likely be near the top of the list. Of course, one lives in the water and the other doesn’t, but the differences are more biologically fundamental than that—sea anemones don’t even have brains.

So it’s surprising that this species in the phylum Cnidarians (along with jellyfish, corals, and other sea creatures) contains an ancient blueprint for bilaterians, of which Homo sapiens are a card-carrying member. A new study by a team of scientists at the University of Vienne discovered that sea anemones, whose Cnidarian status means they grow radially around a central point (after all, what is the “face” of a jellyfish), use a technique commonly associated with bilaterians, known as bone morphogenetic protein (BMP) shuttling, to build their bodies. This complicates the picture of exactly when this technique evolved or if it possibly evolved independently of bilaterians. The results of the study were published last month in the journal Science Advances.

“Not all Bilateria use Chordin-mediated BMP shuttling, for example, frogs do, but fish don’t, however, shuttling seems to pop up over and over again in very distantly related animals making it a good candidate for an ancestral patterning mechanism,” University of Vienna’s David Mörsdorf, a lead author of the study, said in a press statement. “The fact that not only bilaterians but also sea anemones use shuttling to shape their body axes, tells us that this mechanism is incredibly ancient.”

To put it simply, BMPs are a kind of molecular messenger that signals to embryonic cells where they are in the body and what kind of tissue they should form. Local inhibition from an inhibitor named Chordin (which can also act as a shuttle) along with BMP shuttling creates gradients of BMP in the body. When these levels are their lowest, for example, the body knows to form the central nervous system. Moderate levels signal kidney development, and maximum levels signal the formation of the skin of the belly. This is how bilaterians form the body’s layout from back to body.

Mörsdorf and his colleagues found that Chordin also acts as a BMP shuttle—just as displayed in bilaterians like flies and frogs. Thi signals that this particular evolutionary trait likely developed before Cnidarians and bilaterians diverged. Seeing as these two phylums of the animal kingdom have vastly different biological structures, that divergence occurred long ago, likely 600 to 700 million years ago.

“We might never be able to exclude the possibility that bilaterians and bilaterally symmetric cnidarians evolved their bilateral body plans independently,” University of Vienna’s Grigory Genikhovich, a senior author of the study, said in a press statement. “However, if the last common ancestor of Cnidaria and Bilateria was a bilaterally symmetric animal, chances are that it used Chordin to shuttle BMPs to make its back-to-belly axis.”

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Some of the biggest questions in planetary science are written across the dusty surface of Mars. Why did a planet that once had flowing rivers and lakes end up as a frozen desert? How did Mars lose its grip on liquid water – and what does that say about a planet’s ability to stay habitable?

A new study may bring us closer to an answer. Scientists from the University of Chicago have proposed a new model that explains why Mars couldn’t hold on to its early climate.

The mystery of Mars’ climate

The team suggests that Mars had short bursts of warmth triggered by gradual changes in sunlight. But each time conditions improved, the planet pushed itself right back into a deep freeze. That’s very different from Earth, which has stayed habitable for billions of years.

“For years, we’ve had this huge unanswered question for why Earth has managed to keep its habitability while Mars lost it,” said Edwin Kite, a participating scientist on NASA’s Curiosity rover and associate professor at the University of Chicago.

“Our models suggest that periods of habitability on Mars have been the exception, rather than the rule, and that Mars generally self-regulates as a desert planet.”

The case of the missing carbon

Curiosity’s recent discovery of carbonate-rich rocks on Mars helped make this new theory possible. These minerals were the missing link in a puzzle scientists have been trying to solve for years.

If Mars once had a thick, carbon dioxide-rich atmosphere – enough to warm the planet and allow water to flow – where did all that carbon go? “People have been looking for a tomb for the atmosphere for years,” Kite said.

Scientists had suspected that, like Earth, Mars might lock away carbon dioxide in its rocks through chemical reactions with water. But early tests by Mars rovers failed to find those carbonate deposits.

That changed when Curiosity reached higher elevations on Mt. Sharp and finally hit the carbonate-rich layers they’d been hoping to find.

“It really is something you cannot know until you have a rover on the surface,” said study co-author Benjamin Tutolo, a professor at the University of Calgary.

“The chemistry and mineralogy measurements they provide really are essential in our continuing quest to understand how and why planets stay habitable, in order to search for other hospitable worlds out in the universe.”

Mars’ climate cycle worked against life

Mars and Earth started out with a lot in common. Both are rocky planets. Both have water and carbon. Both are at a decent distance from the Sun. Yet only one has remained friendly to life.

The new study explains how small differences added up over time. Earth has a built-in thermostat: carbon cycles from the atmosphere into rocks and back again through volcanic activity.

When Earth heats up, reactions pull carbon dioxide out of the air, cooling things down. Then volcanoes push it back out again, preventing a deep freeze. On Mars, that cycle doesn’t work the same way.

“In contrast to Earth, where there are always some volcanoes erupting, Mars right now is volcanically dormant, and the average rate of volcanic outgassing on Mars is slow,” Kite said.

“So in that situation, you don’t really have a balance between carbon dioxide in and carbon dioxide out, because if you have even a little bit of liquid water, you’re going to draw down carbon dioxide through carbonate formation.”

The role of carbon in Mars’ climate

The carbon imbalance means any brief warming on Mars – such as from a slowly brightening sun – triggers its own undoing. Water reappears. It helps form carbonates. That pulls carbon out of the air. Then the greenhouse effect fades, and Mars cools off again.

The models show Mars could have had warm, wet periods lasting a few million years, followed by dry spells that lasted 100 million years or more. That kind of stop-start habitability, with massive gaps in between, isn’t great for sustaining life.

Traces of environmental catastrophe

Between Curiosity, Perseverance, and the fleet of orbiters circling the planet, we’re finally piecing together a real history of what happened to Mars’ climate.

“Fortunately, Mars preserves a trace of that environmental catastrophe in the rocks on its surface,” said Kite. “And today we’re in a golden age of Mars science, with two plutonium-powered rovers on the surface and an international fleet of spacecraft in orbit that allow us to deeply explore the planet for these traces.”

The more we understand about how Mars lost its atmosphere, the more we can learn about what keeps a planet stable – and what makes it fragile.

The full study was published in the journal Nature.

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The full Moon rises just after 22:00 BST (21:00 UT) on 10 July.

Being so low against the background stars, it creeps slowly across the sky at a very shallow inclination, appearing just 6° above the southeast horizon at 23:40 BST (22:40 UT).

Even when due south and at its highest position above the horizon at 01:30 BST (00:30 UT) on 11 July, it only attains an altitude of 10° as seen from the middle of the UK, although it will get higher when viewed from more southerly latitudes within the Northern Hemisphere.

For weekly stargazing advice, sign up to the BBC Sky at Night Magazine e-newsletter and subscribe to our YouTube channel

The decline to moonset is equally as shallow, the Moon setting behind the southwest horizon around 04:50 BST (03:50 UT).

With such a low declination and shallow pass across the southern horizon, this is a great time to experience the Moon illusion, the strange optical effect of the Moon appearing enormous when it’s close to the horizon.

Let’s look at the science behind behind why some full Moons are higher or lower than others.

Low and high full Moons explained

A full Moon occurs when the Moon is opposite the Sun in the sky or, in other words, when its ecliptic longitude is 180° from the Sun.

The ecliptic is the great circle representing the projection of Earth’s orbital plane into space and, as a result, marks the apparent path of the Sun against the stars. 

The Moon’s orbit is inclined to the ecliptic by around 5°.

Imagine Earth’s orbit as a hoop (the ecliptic). Lay a second hoop on the first hoop and tilt it by 5°.

At certain times, the Moon will be above Earth’s hoop and at other times it will be below it.

The two points where the hoops intersect are known as nodes.

The node where the Moon’s orbit takes the Moon from south to north is an ascending node, the other being a descending node.  

The nodes precess around the ecliptic once in 18.6 years, affecting the Moon’s declination offset from the celestial equator.

The maximum offset is equal to Earth’s axial tilt (23.5°) plus the ecliptic tilt of the Moon’s orbit (5°), resulting in a maximum declination of +28.5° or –28.5°.

This is known as a ‘major lunar standstill’.

A ‘minor lunar standstill’ occurs when the maximum offset is minimised and equals Earth’s axial tilt minus the tilt of the Moon’s orbit: a maximum declination of +18.5° or –18.5°.

Currently, we’re in the wake of a major lunar standstill and this is very evident with the full Moon on the night of 10/11 July.

Observing the Moon illusion on 10 July

If the conditions are clear, try to catch the Moon just after rising or before setting.

This can be tricky as even a bright full Moon will be affected by low atmospheric haze.

Very close to the horizon, this Moon will look artificially huge. Despite this, hold your little finger up at arm’s length and it’ll easily cover it up!

Find out more about how to debunk this optical trick with our guide on how to photograph the Moon illusion.

If you do observe the 10 July 2025 full Moon, or photograph it, get in touch via contactus@skyatnightmagazine.com

It isn’t a bird, it isn’t a plane and it certainly isn’t Superman – but it does appear to be a visitor from beyond our solar system, according to astronomers who have discovered a new object hurtling through our cosmic neighbourhood.

The object, originally called A11pl3Z and now known as 3I/Atlas, was first reported by the Asteroid Terrestrial-impact Last Alert System (Atlas) survey telescope in Rio Hurtado, Chile, on Tuesday.

According to Nasa, subsequent analysis of data collected by various telescopes before this date have extended observations back to 14 June; while further observations have also been made. As a result, experts have been plotting the path of the visitor.

Now about 416m miles away from the Sun and travelling from the direction of the constellation Sagittarius, the object is believed to be whizzing through the solar system at about 60km/s relative to the sun on a highly eccentric, hyperbolic orbit – suggesting that, like the cigar-shaped object ’Oumuamua that appeared in 2017 and the comet 2I/Borisov that turned up in 2019, it is a visitor from afar.

Dr Mark Norris, senior lecturer in astronomy at the University of Central Lancashire, said: “If confirmed, it will be the third known interstellar object from outside our solar system that we have discovered, providing more evidence that such interstellar wanderers are relatively common in our galaxy.”

While the nature of the new visitor was not initially apparent, the Minor Planet Center has revealed that tentative signs of cometary activity have been spotted, noting the object has a marginal coma and short tail. As a result the object has been given the additional name of C/2025 N1.

While some experts have suggested the object could be as large as 12 miles (20km) in diameter – bigger than the space rock that wiped out the non-avian dinosaurs – it seems Earth residents don’t need to worry.

Nasa said: “The comet poses no threat to Earth and will remain at a distance of at least 1.6 astronomical units [about 150m miles].” It said the object would reach its closest approach to the sun around 30 October, coming within about 130m miles of the star – or just within the orbit of Mars. The comet is then expected to leave this solar system and head back out into the cosmos.

Norris said: “As it gets closer, it’s expected to brighten, especially if it turns out to be a comet rather than an asteroid. By the time it makes its closest approach, it will be a relatively easy target for amateur astronomers to observe.”

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For those who cannot wait that long, the Virtual Telescope Project, a network of robotic telescopes, is expecting to host a live feed on its YouTube channel from 11pm UK time on Thursday.