"Extant cyanobacteria utilize a circadian clock to predict the light-dark environmental cycle by Earth's rotation in order to achieve efficient photosynthetic reactions. We wanted to know the evolutionary history of when ancient bacteria acquired the circadian clock and how this property was inherited by the present cyanobacteria," explained Associate Professor Atsushi Mukaiyama of Fukui Prefectural University.

Cyanobacteria, known for their role in shaping the planet's oceans and atmosphere, emerged around 3 billion years ago. These bacteria survived critical planetary shifts, including the Great Oxidation event about 2.3 billion years ago, and two global glaciation periods known as Snowball Earth events, before undergoing further evolutionary transformation during the Neoproterozoic Oxygenation event.

Using fossil evidence and molecular models, researchers believe early cyanobacteria already had basic oxygenic photosynthesis systems. Given the importance of light-dark cycles for photosynthetic efficiency, the team investigated whether a circadian clock existed during these ancient eras.

The researchers utilized the cyanobacteria strain Synechococcus elongatus to study circadian rhythms. By reconstituting the KaiC protein oscillator in vitro, they analyzed how the structure and function of these proteins evolved. Their findings show that early clock proteins displayed rhythmic cycles of 18 to 20 hours, suggesting Earth's faster rotation during that era. "The ancient cyanobacterial clock was synchronized to the cycle of 18 to 20 hours. This means that the history of the Earth's rotation period has been restored by tracing the evolution of clock protein molecules," said Assistant Professor Yoshihiko Furuike from the Institute for Molecular Science.

Originally, the oldest KaiC proteins lacked the features necessary for rhythmic oscillation. However, during pivotal evolutionary periods such as the Great Oxidation and Snowball Earth events, these proteins gained the molecular structure needed to support self-sustained circadian function. This adaptation was later inherited by modern photosynthetic cyanobacteria.

The study not only enhances understanding of how biological clocks evolved but also has implications for synthetic biology. "Our ultimate goal is to design modified cyanobacteria that can adapt to the rotation period of planets and satellites other than Earth by shortening or lengthening the period of the Kai-protein oscillator. Cyanobacteria have taken a long time to tune their clock to 24 hours, but we may be able to achieve even faster evolution using modern knowledge and technology," said Professor Shuji Akiyama of the Institute for Molecular Science.

Research Report:Evolutionary Origins of Self-Sustained Kai protein Circadian Oscillators in Cyanobacteria

]]> Fri, 23 MAY 2025 02:08:56 AEST University Park PA (SPX) May 22, 2025 - The fundamental building blocks for planet formation can exist even in environments with extreme ultraviolet radiation, according to a new study by an international collaboration led by Penn State astronomers. The study leveraged the unparalleled capabilities of NASA's James Webb Space Telescope (JWST) and sophisticated thermochemical modeling to investigate a protoplanetary disk - the dust and gas surrounding a new star that can eventually give rise to planets and other celestial bodies - in one of the most extreme environments in the galaxy.

"Astronomers have long sought to understand how planets form within the swirling disks of gas and dust that encircle young stars," said Bayron Portilla-Revelo, a postdoctoral researcher in astronomy and astrophysics in the Eberly College of Science at Penn State and lead author of the study. "These structures - referred to as protoplanetary disks - are the birthplaces of extrasolar systems, like our own solar system, which formed 4.5 billion years ago. Protoplanetary disks often form in proximity to massive stars that emit substantial amounts of ultraviolet (UV) radiation, potentially disrupting the disks and affecting their capability to form planets. While significant progress has been made by studying protoplanetary disks in nearby star-forming regions, these regions lack the intense UV radiation present in more massive and common stellar nurseries."

UV radiation refers to non-visible light with more energy than visible light. On Earth, this can damage cells, ranging from a mild sunburn to skin cancer. In space, without a planet's atmospheric filters, UV radiation is far more intense. The focus of the study was a young, solar-mass star known as XUE 1, located approximately 5,500 light-years away from our sun, within a region called the Lobster Nebula, also known as NGC 6357. This region is renowned for harboring over 20 massive stars, two of which are among the most massive known in our galaxy and are extreme UV emitters. In the same region, the team observed a dozen lower-mass young stars with protoplanetary disks subjected to intense ultraviolet radiation.

Combining JWST observations with sophisticated astrochemical models, the researchers identified the composition of tiny dust grains in the protoplanetary disk around XUE 1 that will eventually grow to form rocky planets. They found that the disk contains sufficient solid material to potentially form at least 10 planets, each with a mass comparable to that of Mercury. The authors also determined the spatial distribution in the disk of a variety of previously detected molecules, including water vapor, carbon monoxide, carbon dioxide, hydrogen cyanide and acetylene.

"These molecules are expected to contribute to the formation of the atmospheres of emerging planets," said Konstantin Getman, research professor in the Department of Astronomy and Astrophysics at Penn State and co-author of the study. "The detection of such reservoirs of dust and gas suggests that the fundamental building blocks for planet formation can exist even in environments with extreme ultraviolet radiation."

Moreover, based on the absence of certain molecules that serve as tracers of UV irradiation in the light detected by JWST, the team inferred that the protoplanetary disk is compact and devoid of gas in its outskirts. It extends only about 10 astronomical units - a measure based on the average distance between the Earth and sun - from the host star, roughly the distance from the sun to Saturn. This compactness is likely a result of the external UV radiation eroding the outer regions of the disk, according to the research team.

"These findings support the idea that planets form around stars even when the natal disk is exposed to strong external radiation," said Eric Feigelson, distinguished senior scholar and professor of astronomy and astrophysics and of statistics at Penn State. "This helps explain why astronomers are finding that planetary systems are very common around other stars."

The study of XUE 1 represents a pivotal step in understanding the impact of external radiation on protoplanetary disks, the researchers said. It lays the groundwork for future observational campaigns with both space- and ground-based telescopes aimed at building a more comprehensive picture of planet formation across different cosmic environments. This research underscores the transformative capabilities of NASA's James Webb satellite observatory in probing the intricacies of planet formation and highlights the resilience of protoplanetary disks in the face of formidable environmental challenges, according to Portilla-Revelo.

Research Report:XUE: Thermochemical Modeling Suggests a Compact and Gas-depleted Structure for a Distant, Irradiated Protoplanetary Disk

]]> Fri, 23 MAY 2025 02:08:56 AEST Los Angeles CA (SPX) May 22, 2025 - A newly identified planetary system, labeled 2M1510, may be home to one of the most unusual planetary orbits ever observed. A candidate planet appears to loop above and below the poles of a pair of brown dwarfs-celestial bodies too massive to be planets yet too light to ignite like stars. These two brown dwarfs orbit each other closely, while a third brown dwarf circles them at a much greater distance.

Most known planetary systems, including our own, share a common trait: planets orbit in a relatively flat, disk-like alignment around their parent star's equator. This alignment also tends to match the star's rotation, forming what astronomers call a coplanar configuration.

However, 2M1510 b, a potential circumbinary planet, may defy this norm entirely. If its existence is confirmed, its orbit would be almost perfectly perpendicular to the orbital plane of the two central brown dwarfs-an orientation known as a polar orbit. Visualize two spinning disks crossing in an X-shape, and you have the essence of this extreme alignment.

Circumbinary planets-those that orbit two stars simultaneously-are rare. Finding one in a polar configuration is unprecedented. Observations from the European Southern Observatory's Very Large Telescope in Chile suggest this could be the first such discovery.

The detection method used by researchers diverges from the standard transit technique, which identifies exoplanets through temporary dimming when they pass in front of a star. Instead, the team employed radial velocity measurements, detecting tiny shifts in a star's spectral lines due to gravitational tugs from orbiting planets. In this case, slight anomalies in the 21-day orbital rhythm of the brown dwarf pair indicate the gravitational influence of a third, unseen object-presumably the polar-orbiting planet.

To date, scientists have confirmed just 16 circumbinary planets among more than 5,800 known exoplanets, most discovered by the now-retired Kepler Space Telescope. Though polar-orbiting debris disks and protoplanetary structures have been observed before, evidence of a fully formed planet in such an orbit remained elusive-until now.

Led by Thomas A. Baycroft, a Ph.D. candidate at the University of Birmingham in the UK, the international research team detailed their findings in the April 2025 issue of Science Advances. NASA entered the planet into its Exoplanet Archive on May 1, 2025. The full designation of the system is 2MASS J15104786-281874, abbreviated as 2M1510.

Research Report:Evidence for a polar circumbinary exoplanet orbiting a pair of eclipsing brown dwarfs

]]> Fri, 23 MAY 2025 02:08:56 AEST London, UK (SPX) May 19, 2025 - An international research team has provided fresh insights into the origins of oxygenic photosynthesis by revealing the structure of a light-harvesting nanodevice within one of the planet's most ancient cyanobacteria lineages. This breakthrough, detailed in the Proceedings of the National Academy of Sciences, offers a rare glimpse into how early life forms harnessed sunlight, setting the stage for Earth's oxygen-rich atmosphere.

The study, led by researchers from Queen Mary University of London, focused on Photosystem I (PSI), a crucial protein complex that converts light into electrical energy. The team isolated PSI from Anthocerotibacter panamensis, a recently identified cyanobacterium species that diverged from all other known cyanobacteria roughly 3 billion years ago. Unlike its distant cyanobacterial relatives, which separated around 1.4 billion years ago, this species lacks the more familiar stacked membrane structures, known as thylakoids, typically used for efficient photosynthesis.

"While we can't go back in time to directly observe these ancient cyanobacteria," said Dr Ming-Yang Ho of National Taiwan University, the study's lead author, "studying early-branching species like A. panamensis lets us peer into our planet's distant biological past."

Most photosynthetic organisms, including algae and plants, organize their light-capturing machinery into thylakoids, akin to layered solar panels. In contrast, A. panamensis relies on a simpler, single-membrane arrangement, limiting its efficiency and restricting it to low-light environments.

"With this PSI structure now in hand," noted co-author Dr Christopher Gisriel from the University of Wisconsin-Madison, "we can pinpoint which aspects of photosynthesis are ancient and which represent more recent evolutionary innovations."

Their analysis revealed that, despite significant genetic drift, the fundamental architecture of PSI remains largely unchanged, forming a unique three-leaf-clover configuration with more than 300 embedded pigments, including chlorophylls and carotenoids.

Dr Tanai Cardona from Queen Mary University of London concluded, "This discovery suggests that even three billion years ago, the machinery for oxygenic photosynthesis had already achieved remarkable complexity. Tracing the true origin of this process may require looking even further back, to a time before cyanobacteria themselves evolved."

Research Report:Structure and evolution of photosystem I in the early-branching cyanobacterium Anthocerotibacter panamensis

]]> Fri, 23 MAY 2025 02:08:56 AEST Los Angeles CA (SPX) May 15, 2025 - Astronomers have long theorized that frozen water exists in the debris disks surrounding young stars, but definitive evidence has remained elusive - until now. Using the James Webb Space Telescope, researchers have confirmed the presence of crystalline water ice in a dusty disk orbiting a Sun-like star, HD 181327, located 155 light-years away. This finding, published in the journal Nature, represents a major breakthrough in understanding the composition of young planetary systems.

The data, captured using Webb's highly sensitive Near-Infrared Spectrograph (NIRSpec), revealed that the icy particles are distributed alongside fine dust grains, forming a mixture often described as "dirty snowballs." This crystalline water ice is similar to that found in Saturn's rings and icy bodies within our own Kuiper Belt. "Webb unambiguously detected not just water ice, but crystalline water ice," said Chen Xie, the study's lead author and assistant research scientist at Johns Hopkins University.

Previous hints of frozen water in this system came from NASA's Spitzer Space Telescope in 2008, but the older instrument lacked the sensitivity to provide conclusive proof. "When I was a graduate student 25 years ago, my advisor told me there should be ice in debris disks, but prior to Webb, we didn't have instruments sensitive enough to make these observations," said co-author Christine Chen, an associate astronomer at the Space Telescope Science Institute.

HD 181327, significantly younger than our Sun at just 23 million years old, hosts a debris disk reminiscent of our own Kuiper Belt - a region packed with icy bodies, dwarf planets, and rocky fragments. However, unlike our solar system, the water ice in this system is not evenly distributed. Researchers found that the ice concentration varies dramatically across the disk, with over 20% water ice in its outer regions and about 8% in the middle, while almost none is present near the star itself.

The study's authors suggest that ultraviolet radiation from the star likely vaporizes nearby ice, while planetesimals - large, rock-like bodies - may lock up water in their interiors, shielding it from Webb's detectors.

"This is just the beginning," Xie added. "The presence of water ice helps facilitate planet formation. Icy materials may also ultimately be 'delivered' to terrestrial planets that may form over a couple hundred million years in systems like this."

The James Webb Space Telescope, a collaboration between NASA, the European Space Agency (ESA), and the Canadian Space Agency (CSA), is currently the world's most powerful space observatory, probing the farthest reaches of the cosmos.

Research Report:Water ice in the debris disk around HD 181327

]]> Fri, 23 MAY 2025 02:08:56 AEST London UK (SPX) May 21, 2025 - Scientists investigating the origin of life suggest that primitive membranes may have influenced which biomolecules became foundational to life. Their study examines how the earliest cell membranes could have filtered molecules, favoring those used in modern biology.

Cells are defined by their membranes, which regulate what substances can enter or leave. This control is especially relevant to key molecules like the sugar components of DNA and RNA and the amino acids that form proteins. These molecules share an important feature: chirality, or handedness. In biology, all DNA and RNA sugars are right-handed, while amino acids are left-handed. The reason for this consistent stereochemistry has remained an open question in origin-of-life research.

Researchers from the University of Oxford and collaborating institutions studied how membranes with properties similar to those found in archaea-one of the earliest forms of life-allowed various chiral molecules to pass through. They also designed a synthetic membrane combining traits of both archaeal and bacterial membranes. Both types of membranes more readily permitted the right-handed forms of DNA and RNA sugars to pass, while left-handed variants were restricted.

The findings for amino acids were more nuanced. The mixed-type membranes allowed some left-handed amino acids, like alanine, to pass through more easily. Alanine is hypothesized to be one of the first amino acids utilized by primitive life. While these membranes do not replicate the exact conditions of Earth's earliest cells, they offer insight into how molecular selection may have occurred.

The authors stated, "All known life uses a specific stereochemistry: left-handed amino acids and right-handed DNA. Understanding how this evolved is a long-standing mystery key for understanding the origin of life. Our experiments show that a specific type of membrane - the structure that encloses cells - acts as a sieve that selects for the stereochemistry life uses."

Early membranes may have been instrumental in establishing the biochemical asymmetry observed across all life today, acting as selective barriers that helped shape the molecular foundations of biology.

Research Report:Membrane selectivity drives emergence of biomolecular homochirality

]]> Fri, 23 MAY 2025 02:08:56 AEST Los Angeles CA (SPX) May 15, 2025 - Astronomers have developed a new approach to studying planet formation by focusing on "twin" binary star systems, where two stars born at the same time and place orbit each other. This fresh perspective, detailed in a Yale study, suggests that certain binary systems could offer unique insights into how planetary systems form, much like comparing human twins in biological research.

Malena Rice, an assistant professor of astronomy at Yale, and her colleagues have shown that specific "edge-on" configurations of binary star systems may be particularly valuable for planet detection. In these systems, the stars' orbits are perfectly aligned, allowing their gravitational interactions to stabilize the orbits of their planets, potentially reducing the risk of extreme climate variations that could hinder life. This alignment also produces a detectable wobble as the stars move directly toward and away from Earth, boosting observational signals for astronomers.

The research team, including Joseph Hand, a University of Kansas undergraduate and Dorrit Hoffleit Undergraduate Research Scholar, and Yale Ph.D. candidate Konstantin Gerbig, identified nearly 600 edge-on binary systems using data from the European Space Agency's Gaia DR3 stellar catalog. They then simulated the planets likely to orbit these stars, effectively creating a guide for where future astronomers might find new exoplanets.

"This could be an unprecedented avenue for examining how deterministic, or orderly, the process of planet formation is," said Rice. The study's findings provide a roadmap for comparing planets across twin star systems, offering the first true "control sample" for such studies.

]]> Fri, 23 MAY 2025 02:08:56 AEST London, UK (SPX) May 13, 2025 - Researchers from the NASA Jet Propulsion Laboratory, King Abdullah University of Science and Technology (KAUST), and institutes across India and Saudi Arabia have discovered 26 new bacterial species in the cleanrooms used to assemble spacecraft. These microbes exhibit genetic traits linked to extreme resilience, offering insights into how life might survive in space and potential biotech applications.

Cleanrooms are meticulously controlled environments designed to minimize contamination, featuring stringent controls over airflow, temperature, and humidity. Despite these harsh conditions, the study identified numerous extremophiles thriving within these NASA facilities. Many of these newly discovered species possess genes associated with radiation resistance, DNA repair, detoxification of hazardous compounds, and enhanced metabolism, enhancing their chances of survival in space-like conditions.

"Our study aimed to understand the risk of extremophiles being transferred in space missions and to identify which microorganisms might survive the harsh conditions of space. This effort is pivotal for monitoring the risk of microbial contamination and safeguarding against unintentional colonization of exploring planets," said Professor Alexandre Rosado from KAUST, a lead researcher on the project and contributor to multiple NASA working groups focused on planetary protection.

The genetic adaptations found in these microbes could also be harnessed for biotechnology, potentially advancing fields like food preservation, medicine, and industrial processes.

"These findings not only raise important consideration for planetary protection but also open the door for biotechnological innovation," said Junia Schultz, a KAUST postdoctoral fellow and first author of the study. "Space travel provides an opportunity to study microorganisms that possess relevant stress-resistance genes. The genes identified in these newly discovered bacterial species could be engineered for applications in medicine, food preservation, and other industries."

The study also aids NASA in predicting the types of microorganisms astronauts might encounter during space missions and in developing strategies to reduce microbial contamination in cleanrooms.

"KAUST's collaboration with NASA represents a groundbreaking alliance driving the frontiers of space science and astrobiology," said Dr. Kasthuri Venkateswaran, retired Senior Research Scientist at NASA's Jet Propulsion Laboratory and a lead author of the study.

"Together, we are unraveling the mysteries of microbes that withstand the extreme conditions of space - organisms with the potential to revolutionize the life sciences, bioengineering, and interplanetary exploration. This partnership not only supports Saudi Arabia's ambitious vision through the Saudi Space Agency but also reinforces KAUST's emergence as a global leader in microbial and space biology research."

Research Report:Genomic insights into novel extremotolerant bacteria isolated from the NASA Phoenix mission spacecraft assembly cleanrooms

]]> Fri, 23 MAY 2025 02:08:56 AEST Paris, France (SPX) May 12, 2025 - The assembly of the European Space Agency's (ESA) Plato mission is making significant strides, with 24 of the 26 planned cameras now integrated into the spacecraft. Once operational in space, Plato will utilize this extensive array of cameras to survey a vast portion of the sky in its search for terrestrial planets, aiming to uncover potentially habitable worlds.

Assembly work is progressing at OHB in Germany, where the sensitive optical systems are being mounted onto Plato's optical bench - the critical structure responsible for maintaining precise alignment. With 24 of the cameras securely in place, just two more 'fast' cameras remain to be installed in the coming weeks. These final components will complete Plato's unique visual system, designed to capture the faint dimming of starlight caused by transiting exoplanets.

"It's rewarding to see the progress we have made from last year when the work to mount the cameras started: with 24 cameras now in place, we see Plato taking its proper shape," said Thomas Walloschek, ESA's Plato Project Manager.

The 26 cameras, including 24 normal and 2 fast units, will work together to monitor the brightness of over 200,000 stars. By detecting the minute changes in starlight as planets pass in front of their host stars, Plato aims to identify new exoplanets, including potentially Earth-like worlds. The fast cameras will capture high-speed images of the brightest stars, providing rapid data for the spacecraft's orientation and pointing systems.

Plato's mission extends beyond planet hunting. The spacecraft will also study the internal structure of stars by observing 'starquakes' - subtle oscillations that reveal insights into their composition and age. This data will significantly enhance our understanding of stellar physics and the evolution of star systems.

In addition to the camera installations, OHB engineers are assembling Plato's service module, which houses the computers, propulsion systems, power distribution units, and communication components needed to support the spacecraft's scientific mission. The final step in the construction phase will be integrating this service module with the payload module, a critical milestone scheduled for this summer.

]]> Fri, 23 MAY 2025 02:08:56 AEST Washington DC (SPX) May 06, 2025 - Though they don't orbit around our Sun, sub-Neptunes are the most common type of exoplanet, or planet outside our solar system, that have been observed in our galaxy. These small, gassy planets are shrouded in mystery...and often, a lot of haze. Now, by observing exoplanet TOI-421 b, NASA's James Webb Space Telescope is helping scientists understand sub-Neptunes in a way that was not possible prior to the telescope's launch.

"I had been waiting my entire career for Webb so that we could meaningfully characterize the atmospheres of these smaller planets," said principal investigator Eliza Kempton of the University of Maryland, College Park. "By studying their atmospheres, we're getting a better understanding of how sub-Neptunes formed and evolved, and part of that is understanding why they don't exist in our solar system."

Small, Cool, Shrouded in Haze

Before Webb, scientists had very little information on them. While sub-Neptunes are a few times larger than Earth, they are still much smaller than gas-giant planets and typically cooler than hot Jupiters, making them much more challenging to observe than their gas-giant counterparts.

A key finding prior to Webb was that most sub-Neptune atmospheres had flat or featureless transmission spectra. This means that when scientists observed the spectrum of the planet as it passed in front of its host star, instead of seeing spectral features - the chemical fingerprints that would reveal the composition of the atmosphere - they saw only a flat-line spectrum. Astronomers concluded from all of those flat-line spectra that at least certain sub-Neptunes were probably very highly obscured by either clouds or hazes.

A Different Kind of Sub-Neptune?

That temperature threshold is about 1,070 degrees Fahrenheit. Below that, scientists hypothesized that a complex set of photochemical reactions would occur between sunlight and methane gas, and that would trigger the haze. But hotter planets shouldn't have methane and therefore perhaps shouldn't have haze.

The temperature of TOI-421 b is about 1,340 degrees Fahrenheit, well above the presumed threshold. Without haze or clouds, researchers expected to see a clear atmosphere - and they did!

A Surprising Finding

The team found water vapor in the planet's atmosphere, as well as tentative signatures of carbon monoxide and sulfur dioxide. Then there are molecules they didn't detect, such as methane and carbon dioxide. From the data, they can also infer that a large amount of hydrogen is in TOI-421 b's atmosphere.

The lightweight hydrogen atmosphere was the big surprise to the researchers. "We had recently wrapped our mind around the idea that those first few sub-Neptunes observed by Webb had heavy-molecule atmospheres, so that had become our expectation, and then we found the opposite," said Kempton. This suggests TOI-421 b may have formed and evolved differently from the cooler sub-Neptunes observed previously.

Is TOI-421 b Unique?

Aside from being hotter than other sub-Neptunes previously observed with Webb, TOI-421 b orbits a Sun-like star. Most of the other sub-Neptunes that have been observed so far orbit smaller, cooler stars called red dwarfs.

Is TOI-421b emblematic of hot sub-Neptunes orbiting Sun-like stars, or is it just that exoplanets are very diverse? To find out, the researchers would like to observe more hot sub-Neptunes to determine if this is a unique case or a broader trend. They hope to gain insights into the formation and evolution of these common exoplanets.

"We've unlocked a new way to look at these sub-Neptunes," said Davenport. "These high-temperature planets are amenable to characterization. So by looking at sub-Neptunes of this temperature, we're perhaps more likely to accelerate our ability to learn about these planets."

Research Report:TOI-421 b: A Hot Sub-Neptune with a Haze-free, Low Mean Molecular Weight Atmosphere

]]> Fri, 23 MAY 2025 02:08:56 AEST Subscribe to our daily selection of space, military, environment and energy newsletters responseText http://visitor.constantcontact.com/manage/optin/ea?v=0016gbbKsaiGSpQFojVO8ZoHw%3D%3D