Category: 7. Science

The research team reports that drying areas on land are expanding at a rate roughly twice the size of California every year. And, the rate at which dry areas are getting drier now outpaces the rate at which wet areas are getting wetter, reversing long-standing hydrological patterns.

The negative implications of this for available freshwater are staggering. 75% of the world’s population lives in 101 countries that have been losing freshwater for the past 22 years. According to the United Nations, the world’s population is expected to continue to grow for the next 50 to 60 years — at the same time the availability of freshwater is dramatically shrinking.

The researchers identified the type of water loss on land, and for the first time, found that 68% came from groundwater alone — contributing more to sea level rise than the Greenland and Antarctic ice sheets combined.

“These findings send perhaps the most alarming message yet about the impact of climate change on our water resources,” said Jay Famiglietti, the study’s principal investigator and a Global Futures Professor with the ASU School of Sustainability. “Continents are drying, freshwater availability is shrinking, and sea level rise is accelerating. The consequences of continued groundwater overuse could undermine food and water security for billions of people around the world. This is an ‘all-hands-on-deck’ moment — we need immediate action on global water security.”

The researchers evaluated more than two decades of data from the US-German Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On (GRACE-FO) missions, looking at how and why terrestrial water storage has changed since 2002. Terrestrial water storage includes all of Earth’s surface and vegetation water, soil moisture, ice, snow, and groundwater stored on land.

“It is striking how much non-renewable water we are losing,” said Hrishikesh A. Chandanpurkar, lead author of the study and a research scientist for ASU. “Glaciers and deep groundwater are sort of ancient trust funds. Instead of using them only in times of need such as a prolonged drought, we are taking them for granted. Also, we are not trying to replenish the groundwater systems during wet years and thus edging towards an imminent freshwater bankruptcy.”

Tipping point and worsening continental drying

The study identified what seems to be a tipping point around 2014-15 during a time considered “mega El-Niño” years. Climate extremes began accelerating and in response, groundwater use increased and continental drying exceeded the rates of glacier and ice sheet melting.

Additionally, the study revealed a previously unreported oscillation where after 2014, drying regions flipped from being located mostly in the southern hemisphere to mostly in the north, and vice versa for wet regions.

One of the key drivers contributing to continental drying is the increasing extremes of drought in the mid-latitudes of the northern hemisphere, for example, in Europe. Additionally, in Canada and Russia, snow, ice, and permafrost melting increased over the last decade, and the continued depletion of groundwater globally is a major factor.

In a previous study, members of the team studied terrestrial water storage from satellite data spanning 2002 — 2016. In the new study, the team looked at more than 20 years of data and discovered a critical, major development in continental drying. Several regional drying patterns and previously identified localized ‘hotspots’ for terrestrial water storage loss are now interconnected — forming the four continental-scale mega drying regions.

These include:

• Southwestern North America and Central America: this region includes major food-producing regions across the American Southwest, along with major desert cities such as Phoenix, Tucson, Las Vegas, and major metropolitan areas such as Los Angeles and Mexico City.

• Alaska and Northern Canada: this region includes melting alpine glaciers in Alaska and British Columbia, snow and permafrost melting across the Canadian high latitudes, and drying in major agricultural regions such as British Columbia and Saskatchewan

• Northern Russia: this region is experiencing major snow and permafrost melting across the high latitudes

• Middle East-North Africa (MENA) Pan-Eurasia: this region includes major desert cities including Dubai, Casablanca, Cairo, Baghdad and Tehran; major food producing regions including Ukraine, northwest India, and China’s North China Plain region; the shrinking Caspian and Aral Seas; and major cities such as Barcelona, Paris, Berlin, Dhaka and Beijing.

In fact, the study showed that since 2002, only the tropics have continued to get wetter on average by latitude, something not predicted by IPCC (Intergovernmental Panel on Climate Change) climate models — sophisticated computer programs used to project future climate scenarios. Continuous records are critical in understanding the long-term changes in the water cycle.

“This study really shows how important it is to have continuous observations of a variable such as terrestrial water storage,” said Chandanpurkar. “GRACE records are really getting to the length where we are able to robustly see long-term trends from climate variability. More in-situ observations and data sharing would further support in making this separation and inform water management.”

A Planetary Wake-Up Call

The unprecedented scale of continental drying threatens agriculture and food security, biodiversity, freshwater supplies and global stability. The current study highlights the need for ongoing research at scale to inform policymakers and communities about worsening water challenges and opportunities to create meaningful change.

“This research matters. It clearly shows that we urgently need new policies and groundwater management strategies on a global scale,” said Famiglietti, who is also with the Julie Ann Wrigley Global Futures Laboratory and a former Senior Water Scientist at NASA’s Jet Propulsion Laboratory. “While efforts to mitigate climate change are facing challenges, we can address continental drying by implementing new policies around regional and international groundwater sustainability. In turn, this will slow the rate of sea level rise and help preserve water for future generations.”

The study calls for immediate action to slow and reverse groundwater depletion, protect remaining freshwater resources, and adapt to the growing risk of water scarcity and coastal flooding. The research team goes on to say that strategic water management, international cooperation, and sustainable policies are essential to preserving water for future generations and mitigating further damage to planetary systems.

The research will also support an upcoming World Bank Group flagship report that will delve deeper into these findings, including the human and economic implications of continental drying, and present actionable solutions for countries to address the growing freshwater crisis.

About the Study

The findings are based on over 22 years of terrestrial water storage data from US-German GRACE and GRACE-FO satellite missions. The full report details the scientific analyses and regional breakdowns of the drying trends, which have proven robust and persistent despite climate variability.

The research team includes scientists from Arizona State University; Hrishikesh A. Chandanpurkar, FLAME University; John T. Reager and David N. Wiese, JPL; Kaushik Gopalan and Yoshihide Wada, King Abdullah University of Science and Technology; Kauru Kakinuma, Korea Advanced Institute of Science and Technology; and Fan Zhang, The World Bank.

This research was funded by the Julie Ann Wrigley Global Futures Laboratory at Arizona State University, the GRACE Follow-On Science Team, and World Bank Global Water Monitoring.

The new substance repels both water and grease about as well as standard non-stick coatings — but it contains much lower amounts of per- and polyfluoroalkyl substances (PFAS), a family of chemicals that have raised environmental and health concerns.

“The research community has been trying to develop safer alternatives to PFAS for a long time,” says Professor Kevin Golovin, who heads the Durable Repellent Engineered Advanced Materials (DREAM) Laboratory at U of T Engineering.

“The challenge is that while it’s easy to create a substance that will repel water, it’s hard to make one that will also repel oil and grease to the same degree. Scientists had hit an upper limit to the performance of these alternative materials.”

Since its invention in the late 1930s, Teflon — also known as polytetrafluoroethylene or PTFE — has become famous for its ability to repel water, oil and grease alike. Teflon is part of a larger family of substances known as per- and polyfluoroalkyl substances (PFAS).

PFAS molecules are made of chains of carbon atoms, each of which is bonded to several fluorine atoms. The inertness of carbon-fluorine bonds is responsible for the non-stick properties of PFAS.

However, this chemical inertness also causes PFAS to resist the normal processes that would break down other organic molecules over time. For this reason, they are sometimes called ‘forever chemicals.’

In addition to their persistence, PFAS are known to accumulate in biological tissues, and their concentrations can become amplified as they travel up the food chain.

Various studies have linked exposure to high levels of PFAS to certain types of cancer, birth defects and other health problems, with the longer chain PFAS generally considered more harmful than the shorter ones.

Despite the risks, the lack of alternatives means that PFAS remain ubiquitous in consumer products: they are widely used not only in cookware, but also in rain-resistant fabrics, food packaging and even in makeup.

“The material we’ve been working with as an alternative to PFAS is called polydimethylsiloxane or PDMS,” says Golovin.

“PDMS is often sold under the name silicone, and depending on how it’s formulated, it can be very biocompatible — in fact it’s often used in devices that are meant to be implanted into the body. But until now, we couldn’t get PDMS to perform quite as well as PFAS.”

To overcome this problem, PhD student Samuel Au developed a new chemistry technique that the team is calling nanoscale fletching. The technique is described in a paper published in Nature Communications.

“Unlike typical silicone, we bond short chains of PDMS to a base material — you can think of them like bristles on a brush,” says Au.

“To improve their ability to repel oil, we have now added in the shortest possible PFAS molecule, consisting of a single carbon with three fluorines on it. We were able to bond about seven of those to the end of each PDMS bristle.

“If you were able to shrink down to the nanometer scale, it would look a bit like the feathers that you see around the back end of an arrow, where it notches to the bow. That’s called fletching, so this is nanoscale fletching.”

Au and the team coated their new material on a piece of fabric, then placed drops of various oils on it to see how well it could repel them. On a scale developed by the American Association of Textile Chemists and Colorists, the new coating achieved a grade of 6, placing it on par with many standard PFAS-based coatings.

“While we did use a PFAS molecule in this process, it is the shortest possible one and therefore does not bioaccumulate,” says Golovin.

“What we’ve seen in the literature, and even in the regulations, is that it’s the longest-chain PFAS that are getting banned first, with the shorter ones considered much less harmful. Our hybrid material provides the same performance as what had been achieved with long-chain PFAS, but with greatly reduced risk.”

Golovin says that the team is open to collaborating with manufacturers of non-stick coatings who might wish to scale up and commercialize the process. In the meantime, they will continue working on even more alternatives.

“The holy grail of this field would be a substance that outperforms Teflon, but with no PFAS at all,” says Golovin.

“We’re not quite there yet, but this is an important step in the right direction.”

The Moon faces a constant spray of charged particles from the Sun, yet it keeps a whisper thin envelope of atoms swirling above its dusty plains.

Two rival explanations, blasts from micrometeorites and the steady pickoff from the solar wind, have battled for decades.

New experiments with Apollo 16 samples now show that sunlight’s particle stream is far less efficient at stripping atoms than assumed, reshaping the story of how the Moon maintains its scant atmosphere. The finding forces scientists to rethink long-held estimates of erosion rates.

A new look at Moon dust

Professor Friedrich Aumayr of the Institute of Applied Physics at TU Wien led the new study, which drilled into the physics of ion bombardment. His team combined lunar dust tests with detailed computer models to expose hidden quirks in the rock’s texture.

Earlier models treated the surface of the Moon as a smooth glassy slab, so every incoming particle knocked something loose.

Real lunar soil is a messy mix of sharp grains and tiny gaps, making it hard for ions to travel. Instead of blasting atoms into space, they bounce around and quickly lose energy.

That nuance matters because the team measured sputter yields up to ten times lower than the textbook value, a shift great enough to topple decades of balance sheets. It means a smaller share of the exosphere comes from ion impacts than models predicted.

Solar wind doesn’t remove much dust

In space science slang, sputtering is the ping pong ejection of atoms when fast ions strike a surface. The effect shapes everything from comet tails to Europa’s glow, yet its efficiency depends on the microscopic landscape it meets and has proven devilishly hard to pin down.

“Using a specially developed quartz crystal microbalance, we were able to measure the mass loss of lunar material due to ion bombardment with extremely high accuracy,” said Johannes Brötzner, lead author of the study.

Researchers bombarded Apollo grains with helium ions at roughly 135 miles per second, mirroring average solar wind speeds. 

The experiment fed into 3D models that traced every collision inside the dust’s labyrinth. Most ions got trapped, so only about 0.01 atoms escaped per helium ion – a much lower sputter yield.

Moon’s atmosphere comes from dust

The lower yield dovetails with a 2024 isotopic study that analyzed potassium and rubidium in Apollo samples and declared micrometeorite impacts the main gas supplier.

Independent agreement between laboratories using such different tools is rare in planetary science and strengthens the verdict.

Together, the papers imply that tiny dust bullets vaporize far more material than the solar wind can sputter during quiet solar periods. Impact vaporization also lofts atoms with lower energies, matching density patterns recorded by NASA’s LADEE orbiter during its 2013-2014 mapping campaign. 

Shelf life estimates now show that the exosphere would bleed away in just a few lunar days if micrometeorites paused, confirming how transient each atom really is.

The result gives mission planners an environmental baseline for predicting dust behavior around future landers and rovers.

Lessons for future missions

The timing is handy for NASA’s Artemis campaign, which aims to send astronauts to the lunar south pole later this decade.

Accurate erosion rates help engineers judge how solar arrays, optical sensors, and habitat seals will fare during prolonged stays under relentless particle weather.

A better grasp of sputtering also guides remote sensing, because instruments that sniff sodium or helium must subtract the solar wind component before inferring recent impacts. Without that correction, mission scientists could mistake a quiet patch of sky for a lull in incoming dust.

The same physics applies beyond the Moon. When ESA and JAXA’s BepiColombo probe begins full science operations at Mercury in 2027, its instruments will need to separate signals from both sputtering and impacts.

The new sputter yield curve will help scientists translate those signals into details about Mercury’s surface chemistry.

The Moon’s dynamic atmosphere

By trimming the solar wind contribution, the study revises timelines for how quickly space weather alters the Moon’s atmosphere, darkens surface dust, and erases tracks or tool marks.

Equipment left by Apollo crews may thus last longer unaltered, offering historians and tourists clearer snapshots of early human exploration on future visits.

Solar storms can boost ion levels 100-fold, making sputtering briefly dominant again. Tracking those surges will be a task for upcoming CubeSats that hitch rides on Artemis rockets, offering real time context for surface experiments.

Aumayr is already eyeing similar tests with dust from volcanic mare regions to see whether glassy beads behave differently. His group is also adapting the setup for icy terrain, which could refine erosion estimates for moons like Europa and Enceladus.

“Our study provides the first realistic, experimentally validated sputtering yields for actual lunar rock,” said Aumayr. Planetary scientists outside the project are taking note, saying the work turns a page in space weather textbooks. 

The study is published in the journal Communications Earth & Environment.

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There’s a meme that’s been floating around on social media recently, offering encouragement to turn our everyday perspective upside down.

“In the entire Universe, wood is rarer and more valuable than diamonds.”

While diamonds are surprisingly common in the Universe – being made from (very abundant) carbon crystallised in the high pressures of asteroid collisions and gas giant atmospheres – wood is stupendously rare.

It requires life and a whole succession of evolutionary inventions, like DNA and photosynthesis, not to mention the presence of liquid water and a stable atmosphere.

As far as we know, these conditions exist only on Earth. 

And if wood is rare, what about an intelligent, self-aware, communicative and inquisitive being, such as… you?

Life elsewhere in the Universe

In 1961, Frank Drake came up with an equation to calculate the odds of intelligent life evolving, known as the Drake Equation.

It has five factors:

1. the rate of formation of stars suitable for the development of life (some stars are very unstable or violent)
2. the fraction of those stars with planets
3. the number of planets per star that are suitable for life
4. the fraction of those planets on which life actually appears
5. the fraction of those on which intelligent life evolves

Currently, we only have numbers for the first two: we know there are around six or seven new stars born each year in the Milky Way, and it seems likely that the majority of stars have at least one planet.

Estimates for the number of those planets suitable for life (meaning the planet needs to be the right size and temperature) suggest hundreds of millions of potentially habitable planets in our Galaxy.

How many of those actually develop life we can only guess about.

So far, we only know it happened on our planet, but if we’re optimistic, we could assume that simple algae-like life develops on most suitable planets.

However, algae is a far cry from trees. And making the jump from trees to intelligent life?

Again, we can only guess.

Whether or not you’re an optimist, life must certainly be one of the most rare and most precious things in the Universe.

How rare is life?

Drake extended his equation to consider the chance of finding other intelligent civilisations by adding two further factors:

6. the fraction of civilisations that develop technology that we could detect (such as radio signals, laser beams or spaceships)
7. the length of time those civilisations exist for (considering the vast distances of space).

Humans have only been making signals that could be detected in space for about 100 years.

If you put all this together with some reasonable guesses, you end up with about one planet with intelligent life per galaxy at any one time.

So, we’re it!

That means that human life – your life – is extraordinarily rare and that all life is deeply precious. You are one of the most incredible beings that has ever been created by this Universe.

Our mental health takes a plunge when we see ourselves and the life around us as something that doesn’t matter.

The ecosystem then becomes just something to serve us and we stop caring.

But, by turning this perspective upside down and recognising the value and rarity of life, we find a deeper connection and appreciation for all living things.

This article appeared in the August 2025 issue of BBC Sky at Night Magazine

One of the James Webb Space Telescope’s superpowers is its ability to investigate the cosmic dawn, the first few hundred million years after the Big Bang.

The telescope has once again lived up to its reputation, spotting light from a galaxy which existed only 280 million years after the Big Bang, the most distant ever detected.

Known as MoM-z14, it displaces the previous record holder, JADES-GS-z14-0, which existed 300 million years after the Big Bang.

How Webb sees galaxies at the beginning of time

When looking for these distant galaxies so early in the Universe, the James Webb Space Telescope investigates objects with high redshift.

Redshift, often denoted by z, is where the wavelength of light becomes stretched as it travels to us through expanding space.

The redder the light, the higher the redshift and the more distant the object.

You may have heard of the phenomenon in the case of sound; it’s similar to how an ambulance siren drops in pitch as the vehicle speeds away from you. 

By detecting redshifted light with JWST’s infrared instruments, astronomers can determine the distance and composition of early galaxies.

What Webb found at MoM-z14

The newly discovered galaxy, MoM-z14, has a redshift of just over 14.

While the detection of such a distant object is impressive, what’s more surprising is the existence of these galaxies themselves.

“JWST has revealed a stunning population of bright galaxies at surprisingly early epochs, z > 10, where few such sources were expected,” the authors noted in their early pre-publication study.

At this stage in the Universe’s history, astronomers had not anticipated detecting any galaxies using JWST.

Instead, they have found more than 100 relatively bright galaxies from the period just after the cosmic dawn.

JWST observations have also identified the presence of heavier elements, such as carbon and nitrogen, in MoM-z14.

This suggests that even earlier, less chemically evolved galaxies exist.

These galaxies, composed solely of the light elements hydrogen and helium, are still waiting to be discovered.

The researchers comment: “JWST appears poised to drive a series of great expansions of the cosmic frontier – previously unimaginable redshifts, approaching the era of the very first stars, no longer seem far away.”

On July 28, 2025—an asteroid roughly 230 feet across (think the size of a large airplane) named 2025 OW will zip past Earth at nearly 47,000 miles per hour, sailing by at a comfortable distance of about 393,000 miles—that’s about 1.6 times farther than the Moon.But before you grab your flashlight and bunker gear, take some deep breaths. NASA says this is completely routine. Even though the rock is big enough to get attention, it poses absolutely no threat to Earth.NASA’s Jet Propulsion Laboratory (JPL) and the Center for Near-Earth Object Studies (CNEOS) stress that fast-moving space rocks are just part of everyday life in the solar system. “Close approaches happen all the time,” NASA’s media specialist Ian J. O’Neill told ABC News, “and if there was any threat, you’d hear about it clearly from us.”So yes, the asteroid is big—but its orbit is mapped out with precision, and scientists know exactly where it’s going to be for the next century. In short: no surprises, no panic, just routine monitoring.

Can you see it? Not this time

Curious to catch a glimpse of 2025 OW through binoculars or a telescope? Don’t bother. According to Davide Farnocchia, an asteroid expert at NASA, it won’t be visible to the naked eye or standard backyard gear. But the stage is set for a much cooler spectacle coming in 2029, when asteroid Apophis makes an even closer pass—close enough to be visible from Earth without equipment

Just how often do asteroids come close?

A lot more than you’d think. Smaller rocks and space dust—about 100 tons daily—hit Earth harmlessly as they burn up in the atmosphere. Larger asteroids, like 2025 OW, pass near Earth every few years, but Earth impacts of that size happen roughly once every 10,000 years.For real danger to become a concern, the object would have to be at least 460 feet wide and close enough to cross Earth’s orbit in a risky way. 2025 OW doesn’t tick those boxes, even though it’s bigger than 150 feet

What’s next after 2025 OW? Apophis 2029

The next head-turner in asteroid news is 99942 Apophis, due to zoom past Earth in April 2029, at just 38,000 km—which is closer than geostationary satellites. It’s about 1,100 feet wide, and early predictions of possible impact have since been ruled out for at least the next century, according to NASA.“Asteroid Apophis will safely pass close to Earth on April 13, 2029,” NASA says. Monitoring asteroids like 2025 OW is part of NASA’s planetary defense mission—basically an early-warning radar for killer space rocks. Even if most asteroids pose zero risk, the idea is to catch potential threats before they get close, so we can plan mitigation—think spacecraft diversion or evacuation strategies. When objects like YR4 or Apophis show up, scientists run simulations, refine orbits, and assess risk over years.So yes, a plane-sized asteroid is cruising by Earth on July 28th, but there’s no cause for alarm. Space is busy with close calls all the time—most of which we don’t even feel or notice. NASA’s tracking programs give us peace of mind—and a reason to stay excited about cosmic neighbors we never see.Keep an eye on the headlines for 2029’s Apophis, which might actually put on a visible-light show. And don’t sweat 2025 OW—it’s a friendly reminder of our ongoing lunar and planetary watchdog operations.

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The young open cluster NGC 6709 soars through the sky tonight, visible in Aquila with binoculars or any telescope.