New research from Stanford University shows that water sprayed into a mixture of gases thought to be present in Earth’s early atmosphere can lead to the formation of organic molecules with carbon-nitrogen bonds, including uracil, one of the components of DNA and RNA.

The study, published in the journal Science Advances, adds evidence — and a new angle — to the much-disputed Miller-Urey hypothesis, which argues that life on the planet started from a lightning strike. That theory is based on a 1952 experiment showing that organic compounds could form with application of electricity to a mixture of water and inorganic gases.

In the current study, the researchers found that water spray, which produces small electrical charges, could do that work all by itself, no added electricity necessary.

“Microelectric discharges between oppositely charged water microdroplets make all the organic molecules observed previously in the Miller-Urey experiment, and we propose that this is a new mechanism for the prebiotic synthesis of molecules that constitute the building blocks of life,” said senior authorRichard Zare, the Marguerite Blake Wilbur Professor of Natural Science and professor of chemistry in Stanford’sSchool of Humanities and Sciences.

Microlightning’s power and potential

For a couple billion years after its formation, Earth is believed to have had a swirl of chemicals but almost no organic molecules with carbon-nitrogen bonds, which are essential for proteins, enzymes, nucleic acids, chlorophyll, and other compounds that make up living things today.

How these biological components came about has long puzzled scientists, and the Miller-Urey experiment provided one possible explanation: that lightning striking into the ocean and interacting with early planet gases like methane, ammonia, and hydrogen could create these organic molecules. Critics of that theory have pointed out that lightning is too infrequent and the ocean too large and dispersed for this to be a realistic cause.

Zare, along with postdoctoral scholars Yifan Meng and Yu Xia, and graduate student Jinheng Xu, propose another possibility with this research. The team first investigated how droplets of water developed different charges when divided by a spray or splash. They found that larger droplets often carried positive charges, while smaller ones were negative. When the oppositely charged droplets came close to each other, sparks jumped between them. Zare calls this “microlightning,” since the process is related to the way energy is built up and discharged as lightning in clouds. The researchers used high-speed cameras to document the flashes of light, which are hard to detect with the human eye.

Even though the tiny flashes of microlightning may be hard to see, they still carry a lot of energy. The researchers demonstrated that power by sending sprays of room temperature water into a gas mixture containing nitrogen, methane, carbon dioxide, and ammonia gases, which are all thought to be present on early Earth. This resulted in the formation of organic molecules with carbon-nitrogen bonds including hydrogen cyanide, the amino acid glycine, and uracil.

The researchers argue that these findings indicate that it was not necessarily lightning strikes, but the tiny sparks made by crashing waves or waterfalls that jump-started life on this planet.

“On early Earth, there were water sprays all over the place — into crevices or against rocks, and they can accumulate and create this chemical reaction,” Zare said. “I think this overcomes many of the problems people have with the Miller-Urey hypothesis.”

Zare’s research team focuses on investigating the potential power of small bits of water, including how water vapor mayhelp produce ammonia, a key ingredient in fertilizer, andhow water droplets spontaneously produce hydrogen peroxide.

“We usually think of water as so benign, but when it’s divided in the form of little droplets, water is highly reactive,” he said.

Acknowledgements

Zare is also a member of StanfordBio-X, theCardiovascular Institute,Stanford Cancer Institute, and theWu Tsai Neurosciences Institute as well as an affiliate of theStanford Woods Institute for the Environment.

This research received support from the Air Force Office of Scientific Research and the National Natural Science Foundation of China.

The study, published this week in Science Advances, estimates that emissions from WUI fires are proportionately about three times more likely to lead to annual premature deaths than emissions from wildfires in general. This is because the fires, and their associated emissions, are far closer to populated areas.

The work was conducted by an international team of researchers, led by scientists at the U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR). The study drew on a database of WUI fires and advanced computer modeling techniques.

“Even though the emissions of WUI fires are relatively small globally, the health impacts are proportionately large because they’re closer to human populations,” said NSF NCAR scientist Wenfu Tang, the lead author. “Pollutants emitted by WUI fires such as particulate matter and the precursors to ozone are more harmful because they’re not dispersing across hundreds or thousands of miles.”

The study was funded by NOAA and NSF.

The spread of WUI fires

The wildland-urban interface is the geographic area where wildland vegetation and developed land come together or intermingle. WUI areas have been expanding on all populated continents and now constitute about 5% of the world’s land area, excluding Antarctica.

With this expansion have come devastating fires. Some of the deadliest WUI blazes in recent years include the 2009 Black Saturday bushfires in Australia that directly killed 173 people, the 2018 Attica fires in Greece that killed 104, and the 2023 Lahaina Fire in Hawaii that killed 100. At the beginning of this year, a disastrous outbreak of fires in Southern California burned an estimated 16,000 homes, businesses, and other structures, with estimates of financial losses ranging up to $250 billion or higher.

A previous study led by Tang used satellite observations and machine learning techniques to show that the fraction of global fires that occur in WUI areas has increased significantly this century.

Building on that work, Tang and her colleagues wanted to estimate the health effects of the fire emissions beyond the immediate deaths. Certain pollutants associated with smoke, such as fine particulate matter and ground-level ozone, are especially harmful to cardiovascular and respiratory systems.

The researchers turned to an advanced NSF NCAR-based computer model, the Multi-Scale Infrastructure for Chemistry and Aerosols (MUSICA), to simulate pollutants from fires. Their modeling included carbon monoxide chemical tracers, which enabled them to estimate the sources of emissions and differentiate between wildland and WUI fires.

They also used a dataset of WUI fires in the recent two decades worldwide, which Tang and her colleagues developed last year.

To compare emissions of WUI fires with those from wildland fires, the researchers simulated four scenarios. These consisted of: no fires, both WUI and wildland fires, WUI fires only, and wildland fires only. The difference between all fires and just wildland fires indicated the impacts of WUI fire emissions.

The results showed that WUI fire emissions constituted 3.1% of all fire emissions across the six populated continents in 2020. However, the fractional contribution of WUI fire emissions to premature deaths was 8.8% of all fire emissions because of how many people were affected by smoke from WUI fires.

The numbers varied by continent depending on the proximity of dense populations to WUI fires. In North America, for example, WUI fires represented 6% of all fires and 9.3 % of premature deaths from emissions. In Europe, however, those numbers were 11.4% and 13.7%, respectively.

A critical factor that Tang wants to examine next is the difference in emissions from wildland fires that consume trees and other vegetation as opposed to WUI fires that burn down structures that often contain additional toxic substances. The smoke from different burned materials may have widely varying impacts on human health.

“It is very important to have an emission inventory that explicitly accounts for the burning of structures,” Tang said. “We need to know what is being burned in order to determine what is going up in smoke.”

The research, which was supported by the National Institutes of Health, could potentially lead to the identification of biomarkers that would serve as early indicators of a person’s risk for bone health issues later in life.

Bone mineral density is a measure of bone strength quantified by the amount of minerals in bone tissue. It peaks during young adulthood and slowly declines over the rest of the life cycle. BMD serves as an important marker for bone health and is commonly used to predict the risk of osteoporosis and other bone health conditions.

“Proteins are also substantial in the formation and maintenance of bone, and recently more studies have been trying to identify individual proteins associated with bone health,” says Emily Beglarian, the lead author and an epidemiology doctoral candidate in the Department of Population and Public Health Sciences at the Keck School of Medicine.

The study followed 304 obese/overweight Latino adolescents between the ages of 8 to 13 at baseline from the Study of Latino Adolescents at Risk for Type 2 Diabetes over an average period of three years. The researchers examined associations between over 650 proteins and annual measures of BMD, making this one of the first studies to evaluate these associations over years of follow-up. The proteins found to be associated with BMD were then inputted into a protein pathway database.

“The software determined what pathways the proteins were involved in within the human body. Our primary findings were that many of the proteins associated with BMD were involved in inflammatory and immune pathways in adolescent populations. There are other studies that found some of these same pathways were associated in older adult populations,” says Beglarian.

Existing studies suggest chronic inflammation can disrupt normal bone metabolism leading to lower BMD.

Importance of inclusive research

Currently, there are millions of adults in the US living with diseases characterized by low bone mass, and the prevalence is increasing due to our aging population. Childhood is a critical period for the development of BMD and this period can predict lifelong bone health.

“Until now, existing studies have centered on very specific populations. Most of them have small sample sizes, include either Chinese or non-Hispanic white populations, and focus on older adults — primarily on women because osteoporosis is four times more common in women than men,” says Beglarian.

“This is one of the first studies to investigate associations between proteins and BMD in younger populations. Investigating bone mineral density in early stages of life is important to determine how to address factors that may prevent people from reaching their potential peak bone density,” says Beglarian.

Advancing the understanding bone health biomarkers

Additionally, Beglarian examined associations between BMD and a subset of protein markers from the initial proteins, in a separate cohort of young adults. Here she found that several proteins had similar associations with lower BMD. Low BMD is a risk factor for development of adulthood osteopenia and osteoporosis.

The study’s findings could potentially inform the development of biomarkers of bone health to identify people at risk that might benefit from intervention.

“It was interesting to see the way in which our study overlapped and differed with existing studies. Previous research was investigating BMD at the end of life when levels are already much lower,” she says. “Through my research I hope to address factors that decrease BMD earlier in life to help people get to their highest potential peak density, so they are set up over the rest of their lifetime to have a higher BMD.”

About this study

Additional co-authors include Jiawen Carmen Chen, Zhenjiang Li, Elizabeth Costello, Hongxu Wang, Hailey Hampson, Zhanghua Chen, Sarah Rock, Wu Chen, Max T Aung, Frank D Gilliland, Rob McConnell, Sandrah P Eckel, David V Conti, Jesse A Goodrich, Lida Chatzi from USC; Tanya L Alderete from Johns Hopkins Bloomberg School of Public Health; Damaskini Valvi from the Icahn School of Medicine at Mount Sinai; Nahid Rianon from UTHealth McGovern Medical School; Michael I Goran from The Saban Research Institute of Children’s Hospital Los Angeles, and Miryoung Lee from University of Texas Health Science Center at Houston.

This work is primarily supported by grant R01ES029944 from the National Institute of Environmental Health Sciences (NIEHS], the National Institutes of Health (NIH) grant R01DK59211 (PI MG), the Southern California Children’s Environmental Health Center grants funded by NIEHS (5P01ES022845, P30ES007048, 5P01ES011627), the United States Environmental Protection Agency (RD83544101), and the Hastings Foundation.

“These atoll islands have the most threatened fresh groundwater on earth, and are relied upon by some of the most remote communities,” says Flinders University’s Professor Adrian Werner.

Modelling of a specialised form of fresh groundwater extraction, featuring horizontal wells, has the potential to reduce the risk of aquifer reserves being overused, and to provide drinking water of lower salinity.

Such wells, also known as infiltration galleries or skimming wells, play a crucial role in extracting fresh groundwater on atoll islands. They typically comprise horizontal or slightly inclined slotted pipes, surrounded by a gravel pack and connected to an extraction well or sump.

These infiltration galleries skim fresh groundwater from shallow depths while minimising the risk of saltwater intrusion beneath thin subterranean freshwater lenses, which typically range 3 to 21 metres in thickness. The design, construction and operation of these galleries need to be precise to avoid drawing seawater into the island’s water supply.

Such galleries are currently in operation across several atoll islands, and Flinders researchers have focused on nine small islands in the Pacific Ocean, including Kiritimati Atoll and Bonriki Island in Kiribati, Lifuka Island in Tonga, and the Cocos Islands.

While these systems provide crucial freshwater supplies, information is lacking about the optimal layout of infiltration galleries, pipe characteristics and pumping rates. There is also limited data on the performance of these galleries — specifically pumping rates and salinity levels — on small atoll islands.

A research team from the National Centre for Groundwater Research and Training (NCGRT) at Flinders University, led by Professor Werner and Dr Amir Jazayeri, was commissioned by the Pacific Community (SPC), under the management of Mr Peter Sinclair, to address these research gaps and evaluate the performance of infiltration galleries across Pacific islands.

They also performed modelling to assess how infiltration galleries on atolls will be affected by rising sea levels in the future.

This comprehensive study involved collecting extensive data on the hydraulic properties of atoll island aquifers and analysing the design of infiltration galleries across the region.

Valuable insights were gathered from infiltration gallery operators during Flinders University’s participation in the Pacific Groundwater Gallery Knowledge Exchange (PGGKE) workshop, held on Kiritimati Atoll (Kiribati) in November 2023.

The research also incorporated computer modelling simulations and physical laboratory experiments conducted at Flinders University’s Sand Tank Laboratory, to gain a deeper understanding of infiltration gallery performance.

The findings of this study have been published as a United Nations Development Programme (UNDP) scientific technical report, providing critical guidance for sustainable groundwater management in the Pacific.

“While many studies have examined horizontal wells in other contexts, the specific conditions of small islands, especially atolls, places unique demands on infiltration galleries,” says Professor Werner.

Dr Jazayeri says the research team continues to focus on solutions to protect freshwater resources and serve the demands of isolated communities across the Pacific, using a wide range of research techniques.

“We believe that expanding the use of infiltration gallery systems in other coastal aquifers can significantly contribute to managing crucial coastal freshwater resources, both in Australia and globally,” says Dr Jazayeri.

The review article — ‘Construction and performance of infiltration galleries (skimming wells): A review of applications to Pacific atoll islands’ (2025) by Amir Jazayeri and Adrian Werner — has been published in the Journal of Hydrology. DOI:10.1016/j.jhydrol.2024.132581

Professor Werner is confident the findings will have wider applications across many countries.

“The insights gained from applying infiltration galleries to Pacific atolls offers opportunities for more widespread applications within continental aquifers, especially to capture submarine fresh groundwater discharge that is otherwise lost through mixing with seawater and to mitigate seawater intrusion,” he says.

“This all contributes to global groundwater management strategies.”

Professor Werner says further research is now needed into optimal designs and wider application in continental aquifers.

Astrophysicists have once again enriched our knowledge of the cosmos with a new discovery: two small planets orbiting TOI-1453. Located at around 250 light years from Earth in the Draco constellation, this star is part of a binary system (a pair of stars orbiting each other) and is slightly cooler and smaller than our Sun. Around this star are two planets, a super-Earth and a sub-Neptune. These are types of planets that are absent from our own solar system, but paradoxically constitute the most common classes of planet in the Milky Way. This discovery sheds light on a planetary configuration that could provide valuable clues to the formation and evolution of planets.

Using data from NASA’s Transiting Exoplanet Survey Satellite (TESS) and the HARPS-N high-resolution spectrograph, the researchers were able to identify TOI-1453 b and TOI-1453 c, the two exoplanets orbiting TOI-1453. “The two planets present an interesting contrast in their characteristics,” explains Manu Stalport, astrophysicist at the University of Liège and first author of the publication. TOI-1453 b is a super-Earth, slightly larger than our planet, and probably rocky. It completes its orbit in just 4.3 days, making it a very close planet to its star. In contrast, TOI-1453 c is a sub-Neptune, about 2.2 times the size of Earth but with an extraordinarily low mass of just 2.9 Earth masses. This makes it one of the least dense sub-Neptunes ever discovered, which raises questions about its composition.”

Transit and radial velocity

Detecting exoplanets remains a complex task. The team relied on two key methods to confirm their discoveries. The transit method (TESS data) measures the size and orbital period as the planet passes in front of its host star, causing a slight decrease in brightness. The second method used is radial velocity measurement (HARPS-N data), which involves observing the variations in the velocity of a star under the effect of the gravity of a planet orbiting it. By studying the gravitational influence exerted by the planets on their host star, the researchers were able to measure their masses and densities.

“All these observations have revealed that TOI-1453 c is extremely light for its size, suggesting that it could have a thick hydrogen-rich atmosphere or a composition dominated by water. This makes it an ideal candidate for future atmospheric studies,” enthuses Manu Stalport. Understanding their formation and evolution could provide clues about the development of planetary systems, including our own.”

What’s more, the two planets orbit in a configuration close to a 3:2 resonance, meaning that for every three orbits of the inner planet, the outer planet completes almost exactly two. Such resonances are considered a natural consequence of orbital migration, offering clues as to how the planets move and settle into their final orbits.

This discovery opens up new research prospects. Observational instruments such as the James Webb Space Telescope (JWST) could analyse TOI-1453 c’s atmosphere to determine its main composition. If this planet has a substantial hydrogen-rich atmosphere or a water-dominated interior, it could redefine our understanding of sub-Neptunes and their formation.