Historical geography helps researchers solve 2,700-year old eclipse mystery

Artist’s interpretation of an ancient total solar eclipse. This illustration is based on artistic imagination and does not represent the exact appearance of the eclipse recorded in 709 BCE.
Image Credit: Kano Okada, Nagoya University
Based on an image by Phil Hart / NASA

Humanity’s earliest datable record for a total solar eclipse allows scientists to derive accurate measurements of Earth’s ancient rotation speed and provides independent validation of solar cycle reconstruction in the 8th century BCE.

An international team of researchers has used knowledge of historical geography to reexamine the earliest datable total solar eclipse record known to the scientific community, enabling accurate measurements of Earth’s variable rotation speed from 709 BCE. The researchers calculated how the Sun would have appeared from Qufu, the ancient Chinese capital of the Lu Duchy, during the total solar eclipse. Using this information, they analyzed the ancient description of what has been considered the solar corona—the dim outer atmosphere of the Sun visible to the naked eye only during total eclipses—and found that its morphology supports recent solar cycle reconstructions for the 8th century BCE. 

Their findings, published in Astrophysical Journal Letters, provide reliable new data about Earth’s rotation speed during this period and suggest the Sun was becoming more active after a long quiet period, independently confirming what other scientists have found using radiocarbon analysis. 

Researchers identify kidney sensor that helps control fluid balance

Rose Hill, Ph.D., second from left,studies sensory nerves within the kidneys at OHSU. Her new study identified a protein that acts as a pressure sensor in the kidneys, which helps the body control fluids and blood pressure. With her are lab team members: Taylor Krilanovich, Lily Schainker and Janelle Doyle.
 Photo Credit: OHSU/Christine Torres Hicks

A new study has identified a critical “pressure sensor” inside the kidney that helps the body control blood pressure and fluid levels. The finding helps explain how the kidneys sense changes in blood volume — something scientists for decades have known occurs but didn’t have a mechanistic explanation.

Researchers at Oregon Health & Science University and collaborating institutions discovered that a protein called PIEZO2 acts as a mechanical sensor in the kidney. When blood volume changes, this protein helps trigger the release of renin, a hormone that starts a chain reaction known as the renin-angiotensin-aldosterone system, or RAAS. The system is one of the body’s main tools for keeping blood pressure stable and making sure the body has the right balance of salt and water.

SwRI may have solved a mystery surrounding Uranus’ radiation belts

SwRI scientists compared space weather impacts of a fast solar wind structure (first panel) driving an intense solar storm at Earth in 2019 (second panel) with conditions observed at Uranus by Voyager 2 in 1986 (third panel) to potentially solve a 39-year-old mystery about the extreme radiation belts found. The "chorus wave" is a type of electromagnetic emission that may accelerate electrons and could have resulted from the solar storm.
Image Credit: Southwest Research Institute

Southwest Research Institute (SwRI) scientists believe they may have resolved a 39-year-old mystery about the radiation belts around Uranus. 

In 1986, when Voyager 2 made the first and only flyby of Uranus, it measured a surprisingly strong electron radiation belt at significantly higher levels than anticipated. Based on extrapolations from other planetary systems, Uranus’ electron radiation belt was off the charts. Since then, scientists have wondered how the Uranian system could support such an intense trapped electron radiation belt, at a planet unlike anything else in the solar system. 

A New Kind of Copper from the Research Reactor

In front of the nuclear reactor at TU Wien
Photo Credit: © TU Wien

The copper isotope Cu-64 plays an important role in medicine: it is used in imaging processes and also shows potential for cancer therapy. However, it does not occur naturally and must be produced artificially — a complex and costly process. Until now, Cu-64 has been generated by bombarding nickel atoms with protons. When a nickel nucleus absorbs a proton, it is transformed into copper. At TU Wien, however, a different pathway has now been demonstrated: Cu-63 can be converted into Cu-64 by neutron irradiation in a research reactor. This works thanks to a special trick — so-called “recoil chemistry.” 

New deep-sea species discovered during mining test

A small marine bristle worm. The group from the University of Gothenburg has been working with this species. It is one of the few species that is slightly more common in this area. The animal is about 1-2 mm long.
Photo Credit: Natural History Museum, London & Göteborgs Universitet

There is a high demand globally for critical metals, and many countries want to try extracting these sought-after metals from the seabed. An international study, which has discovered large numbers of new species at a depth of 4,000 meters, shows that such mining has less of a negative impact than expected. However, species diversity declined by a third in the tracks of the mining machine. 

In a major research project, marine biologists from several countries have attempted to map life in one of the least explored places on Earth: the deep-sea floor of the Pacific Ocean. 

UCLA study uncovers how a key protein helps breast cancer cells survive in hostile conditions

NBCn1 (purple) sits in the cell membrane and brings two sodium ions (2Na⁺) and one carbonate ion (CO₃²⁻) into the cell, raising its internal pH. This helps breast cancer cells stay alkaline and survive in low-oxygen, acidic tumor environments.
Illustration Credit: Courtesy of UCLA/Health

UCLA scientists have characterized the structure and function of a key survival protein in breast cancer cells that helps explain how these tumors resist environmental stress and thrive in acidic, low-oxygen environments that would normally be toxic to healthy cells.

Breast cancer cells rely on a transporter protein called NBCn1 to bring alkali ions into the cell and maintain a favorable internal pH. Using advanced cryo-electron microscopy combined with computational modeling, the researchers showed that NBCn1 moves two sodium ions and one carbonate ion through an efficient “elevator-like” motion that minimizes energy use. This allows NBCn1 to achieve a high transport rate of approximately 15,000 ions per second, helping tumor cells maintain an internal pH that promotes survival, division and resistance to acidic stress. 

Icy Hot Plasmas: Fluffy, Electrically Charged Ice Grains Reveal New Plasma Dynamics

Ice grains, illuminated by a green sheet of laser light, are suspended in the plasma discharge (purple). Insets show individual ice grains imaged with 20x magnification.
Image Credit: Bellan Plasma Group/Caltech

When a gas is highly energized, its electrons get torn from the parent atoms, resulting in a plasma—the oft-forgotten fourth state of matter (along with solid, liquid, and gas). When we think of plasmas, we normally think of extremely hot phenomena such as the Sun, lightning, or maybe arc welding, but there are situations in which icy cold particles are associated with plasmas. Images of distant molecular clouds from the James Webb Space Telescope feature such hot–cold interactions, with frozen dust illuminated by pockets of shocked gas and newborn stars.

Now a team of Caltech researchers has managed to recreate such an icy plasma system in the lab. They created a plasma in which electrons and positively charged ions exist between ultracold electrodes within a mostly neutral gas environment, injected water vapor, and then watched as tiny ice grains spontaneously formed. They studied the behavior of the grains using a camera with a long-distance microscope lens. The team was surprised to find that extremely "fluffy" grains developed under these conditions and grew into fractal shapes—branching, irregular structures that are self-similar at various scales. And that structure leads to some unexpected physics.

A speed camera for the universe

The stars (or rather galaxies) of the show.
A montage of eight time-delay gravitational lens systems. There’s an entire galaxy at the center of each image, and the bright points in rings around them are gravitationally lensed images of quasars behind the galaxy. These images are false-color and are composites of data from different telescopes and instruments.
Image Credit: ©2025 TDCOSMO Collaboration et al.
(CC BY-ND 4.0)

There is an important and unresolved tension in cosmology regarding the rate at which the universe is expanding, and resolving this could reveal new physics. Astronomers constantly seek new ways to measure this expansion in case there may be unknown errors in data from conventional markers such as supernovae. Recently, researchers including those from the University of Tokyo measured the expansion of the universe using novel techniques and new data from the latest telescopes. Their method exploits the way light from extremely distant objects takes multiple pathways to get to us. Differences in these pathways help improve models on what happens at the largest cosmological scales, including expansion.

New marine sponges provide clues about animal evolution

Paco Cárdenas and Julio A. Díaz have described new sponges found off the coast of Spain. The researchers discovered that the sponges produce a substance of potential interest for drug development.
 Photo Credit: Mikael Wallerstedt

A completely new order of marine sponges has been found by researchers at the Museum of Evolution, Uppsala University. The sponge order, named Vilesida, produces substances that could be used in drug development. The same substances support the hypothesis that sponges – and therefore animals – emerged 100 million years earlier than previously thought. 

Sponges are among the most challenging animals in the tree of life to identify and classify. For this reason, many sponges lack a formal name, which is unusual in other animal groups. While the discovery by scientists of new species of marine invertebrates is an everyday occurrence, it is far less common to identify entirely new genera or families. The discovery of a completely new order is rare: only twelve new animal orders have been described in the last five years. 

Heat and drought change what forests breathe out

Qingyuan County forest research site
Photo Credit: Kai Huang/UCR

Scientists have long warned that rising global temperatures would force forest soils to leak more nitrogen gas into the air, further increasing both pollution and warming while robbing trees of an essential growth factor. But a new study challenges these assumptions. 

After six years of UC Riverside-led research in a temperate Chinese forest, researchers have found that warming may be reducing nitrogen emissions, at least in places where rainfall is scarce.

The findings, published in the Proceedings of the National Academy of Sciences, are the result of UCR’s collaboration with a large team of graduate students and postdoctoral researchers stationed in China’s Shenyang City. These researchers maintained the infrastructure used to take more than 200,000 gas measurements from forest soil over six years.