Category: 7. Science

A new study finds that galaxy clusters — cosmic cities packed with thousands of galaxies — trace invisible highways of dark matter stretching up to a billion light years across the universe. Even more remarkable, the clusters point the way to their neighbors.

FLAGSTAFF, Ariz., July 7, 2025 /PRNewswire/ — In a groundbreaking study of 1.58 million galaxy clusters, an international team of astronomers led by Dr. Michael West of Lowell Observatory mapped how the universe’s largest structures are arranged. They found that most clusters are elongated, like grains of rice. But unlike rice scattered at random, these clusters tend to align with one another, their elongated shapes pointing toward their neighbors like arrows tracing hidden highways across the cosmos. The team’s findings were published today in The Astrophysical Journal Letters.

“It’s like discovering that New York, Madrid, Rome, and Beijing were all built facing the same direction, perfectly aligned despite being thousands of miles apart,” said lead author Dr. Michael J. West of Lowell Observatory.

Astronomers have seen neighboring galaxy clusters align before, but never across such vast distances. This new study shows that clusters, like cities, are shaped by their surroundings. The biggest clusters develop where multiple dark matter highways intersect. Dark matter — the mysterious, invisible substance that makes up most of the universe’s mass — appears to determine cluster shapes and locations.

By examining the most distant clusters, the astronomers peered billions of years into the past and found that neighboring clusters were already aligned when the universe was still young — less than half its current age.

“This gives us a rare glimpse into how the universe grew up,” said co-author Dr. Maret Einasto of Tartu Observatory in Estonia. “It shows that the foundation of the universe’s largest structures was laid early, and galaxies have been following those paths ever since.”

To test their findings, the team turned to advanced computer simulations of the universe’s evolution. These simulations helped the scientists explore whether cluster alignments like those observed emerge naturally from known physics. They used the Last Journey simulation, developed by researchers at Argonne National Laboratory. This simulation tracks the motion of over a trillion particles as gravity shapes a virtual universe. The simulation revealed the same alignment patterns, supporting the idea that galaxy clusters form as matter flows along the universe’s dark matter highways.

“This is a cosmic traffic report,” said co-author Dr. Roberto De Propris of the Botswana International University of Science & Technology. “The cluster alignments show us which way galaxies have been flowing for billions of years.”

Other members of the team include Z.L. Wen and J.L. Han of the Chinese Academy of Sciences, whose comprehensive catalog of galaxy clusters made this research possible.

The full published paper can be found here: https://iopscience.iop.org/article/10.3847/2041-8213/ade66d

About Lowell Observatory
Lowell Observatory is a private, nonprofit 501(c)(3) research institution, founded in 1894 by Percival Lowell atop Mars Hill in Flagstaff, Arizona. The Observatory has been the site of many important discoveries, including the first detection of large recessional velocities (redshift) of galaxies by Vesto Slipher in 1912-1914 (a result that led ultimately to the realization that the universe is expanding), and the discovery of Pluto by Clyde Tombaugh in 1930.

Today, the Observatory’s 14 tenured astronomers use ground-based telescopes around the world, telescopes in space, and NASA planetary spacecraft to conduct research in diverse areas of astronomy and planetary science. Lowell Observatory currently operates multiple research instruments at its Anderson Mesa station, east of Flagstaff, and the 4.3-meter Lowell Discovery Telescope near Happy Jack, Arizona. Prior to the pandemic, the observatory also welcomed more than 100,000 guests per year to its Mars Hill campus in Flagstaff, Arizona, for a variety of educational experiences, including historical tours, science presentations, and telescope viewing.

SOURCE Lowell Observatory

We present an analysis on the detection viability of refraction effects in Kepler’s exoplanet atmospheres using binning techniques for their light curves in order to compare against simulated refraction effects.

We split the Kepler exoplanets into sub-populations according to orbital period and planetary radius, then search for out-of-transit changes in the relative flux associated with atmospheric refraction of starlight. The presence of refraction effects – or lack thereof – may be used to measure and set limits on the bulk properties of an atmosphere, including mean molecular weight or the presence of hazes.

In this work, we use the presence of refraction effects to test whether exoplanets above the period-radius valley have H/He atmospheres, which high levels of stellar radiation could evaporate away, in turn leaving rocky cores below the valley.

We find strong observational evidence of refraction effects for exoplanets above the period-radius valley based on Kepler photometry, however those related to optically thin H/He atmospheres are not common in the observed planetary population.

This result may be attributed to signal dampening caused by clouds and hazes, consistent with the optically thick and intrinsically hotter atmospheres of Kepler exoplanets caused by relatively close host star proximity.

Dereck-Alexandre Lizotte, Jason Rowe, James Sikora, Michael R. B. Matesic

Comments: 13 pages, 13 figures, to be submitted in AJ
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2507.02126 [astro-ph.EP] (or arXiv:2507.02126v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2507.02126
Focus to learn more
Submission history
From: Dereck-Alexandre Lizotte
[v1] Wed, 2 Jul 2025 20:20:24 UTC (384 KB)
https://arxiv.org/abs/2507.02126

Astrobiology

Over the past two decades, more than one-fifth of the world’s oceans, an area exceeding 75 million square kilometers, have undergone a phenomenon known as ocean darkening, according to groundbreaking new research.

Ocean darkening occurs when changes in water clarity reduce the depth of photic zones, the sunlit layers of the ocean that support 90% of marine life. These zones are crucial for ecological interactions driven by sunlight and moonlight, and any disruption could have far-reaching consequences.

The study, published in Global Change Biology, analyzed satellite data and numerical models to track annual shifts in the depth of the photic zone worldwide. Between 2003 and 2022, researchers found that 21% of the ocean had experienced significant darkening.

Some regions suffered particularly dramatic losses in light penetration:

• Over 9% of the ocean, equivalent to the size of Africa, saw photic zones shrink by more than 50 meters.
• In 2.6% of the ocean, light penetration dropped by over 100 meters.

At the same time, the researchers observed that around 10% of the ocean had become lighter, illustrating complex shifts in marine ecosystems.

The team, led by scientists from the University of Plymouth and Plymouth Marine Laboratory, has been studying artificial light at night (ALAN) for over a decade. However, they say ocean darkening is likely due to different factors.

Near coastlines, darkening appears to be linked to agricultural runoff, increased rainfall, and sediment loading. In open ocean regions, shifts in algal bloom patterns and rising sea surface temperatures have reduced light penetration, affecting the ecosystem.

The changes are especially pronounced in climate-sensitive regions, such as the Arctic, Antarctic, and the Gulf Stream. Coastal areas, including enclosed seas such as the Baltic, have also experienced widespread darkening due to excess nutrients fueling the growth of plankton.

The study found varying trends in UK waters:

• The darkening was observed in parts of the North Sea, Celtic Sea, and the eastern coasts of England and Scotland.
• In contrast, much of the English Channel and waters near Scotland’s northern isles became lighter.

Although the full ecological impact remains uncertain, researchers warn that ocean darkening could disrupt marine food chains, affect biodiversity, and reduce the ocean’s ability to support key ecosystem services.

As climate change accelerates, understanding these shifts will be crucial for protecting ocean health.

Journal Reference

1. Davies, T. W., & Smyth, T. (2025). Darkening of the Global Ocean. Global Change Biology, 31(5), e70227. DOI: 10.1111/gcb.70227

Scientists at the Jules Stein Eye Institute at the David Geffen School of Medicine at UCLA have discovered that certain retinal cells can rewire themselves when vision begins to deteriorate in retinitis pigmentosa, a genetic eye disease that leads to progressive blindness. In a study using mouse models, researchers found that rod bipolar cells, neurons that normally receive signals from rods that provide night vision, can form new functional connections with cones that provide daytime vision when their usual partners stop working. The study appears in Current Biology.

Why it matters

Retinitis pigmentosa affects millions of people worldwide and is a leading cause of inherited blindness. While the disease often progresses slowly, with some patients maintaining a surprising amount of usable vision into middle age, little is known about how retinal circuits adapt to cell loss. Understanding these natural adaptation mechanisms could reveal new targets for treatments aimed at preserving vision.

What the study did

Researchers used rhodopsin knockout mice that model early retinitis pigmentosa, where rod cells cannot respond to light and degeneration proceeds slowly. They made electrical recordings from individual rod bipolar cells, neurons that normally connect to rods, to see how these cells behaved when their usual input was lost. The team also used additional mouse models lacking different components of rod signaling to determine what triggers the rewiring process. They supported their single-cell findings with whole-retina electrical measurements.

What they found

Rod bipolar cells in mice lacking functional rods showed large-amplitude responses driven by cone cells instead of their normal rod inputs. These rewired responses were strong and had the expected electrical characteristics of cone-driven signals. The rewiring occurred specifically in mice with rod degeneration, but not in other mouse models that lacked rod light responses without actual cell death. This suggests that the cellular rewiring is triggered by the degeneration process itself, rather than simply the absence of light responses or broken synapses.

The findings complement the research team’s previous 2023 work showing that individual cone cells can remain functional even after severe structural changes in later disease stages. Together, these studies reveal that retinal circuits maintain function through different adaptation mechanisms at various stages of disease progression. The research shows that retinal adaptation occurs through different mechanisms at various disease stages, which could help scientists identify new targets for preserving vision in patients with inherited retinal diseases.

From the experts

“Our findings show that the retina adapts to the loss of rods in ways that attempt to preserve daytime light sensitivity in the retina,” said senior author A.P. Sampath, Ph.D. of the Jules Stein Eye Institute at the David Geffen School of Medicine at UCLA. “When the usual connections between rod bipolar cells and rods are lost, these cells can rewire themselves to receive signals from cones instead. The signal for this plasticity appears to be degeneration itself, perhaps through the role of glial support cells or factors released by dying cells.”

What’s next

One of the open questions is whether this rewiring represents a general mechanism used by the retina when rods die. The group is currently exploring this possibility with other mutant mice that carry mutations to rhodopsin and other rod proteins that are known to cause retinitis pigmentosa in humans.

As the pharmaceutical industry moves toward more sustainable and responsible practices, the spotlight is turning to analytical techniques—and how they must evolve to meet both scientific and environmental demands. In this special HPLC 2025 interview with LCGC International, we sit down with Paul Ferguson, a leading voice in sustainability in the pharmaceutical sector, to explore the intersection of green chemistry and emerging therapeutics.

Ferguson shares insights on how method design is adapting to support sustainability in the development of new modality therapeutics. We discuss the practicalities and trade-offs of greener alternatives—such as replacing trifluoroacetic acid (TFA) with methanesulfonic acid.

From mobile phase volume reduction to the environmental implications of liquid chromatography–mass spectrometry (LC–MS) flow strategies, this discussion offers a forward-looking perspective on what it means to build analytical methods that are not only effective but also sustainable.

Ferguson addressed the following questions:

• As sustainability becomes a key consideration in pharmaceutical development, how is chromatographic method design evolving to support greener practices, particularly for new modality therapeutics such as peptides and oligonucleotides?

• What are the primary sustainability benefits and trade-offs of using MSA (methanesulfonic acid) as a replacement for TFA/DFA in peptide analysis?

• How can reducing mobile phase volumes serve as a practical strategy for reducing the environmental impact of chromatographic methods, and what limitations might be encountered?

• What impact does the on/off mechanism have on sustainability, particularly in non-optimized LC–MS systems, and how does it compare to traditional continuous-flow approaches?

• Do you have general advice on how separation science can become more sustainable?

Paul Ferguson was appointed professor by special appointment at the Faculty of Science of the University of Amsterdam, Netherlands, in March 2025. His chair, “Separation of Biomacromolecules, with an Emphasis on Sustainable Analytical Science,” is part of the Van ‘t Hoff Institute for Molecular Sciences (HIMS) and endowed by the Bèta Plus foundation. He is also an active member of The Chromatographic Society (ChromSoc) and LCGC international’s editorial advisory board (EAB).

During photosynthesis, an enzyme called rubisco catalyzes a key reaction — the incorporation of carbon dioxide into organic compounds to create sugars. However, rubisco, which is believed to be the most abundant enzyme on Earth, is very inefficient compared to the other enzymes involved in photosynthesis.

MIT chemists have now shown that they can greatly enhance a version of rubisco found in bacteria from a low-oxygen environment. Using a process known as directed evolution, they identified mutations that could boost rubisco’s catalytic efficiency by up to 25 percent.

The researchers now plan to apply their technique to forms of rubisco that could be used in plants to help boost their rates of photosynthesis, which could potentially improve crop yields.

“This is, I think, a compelling demonstration of successful improvement of a rubisco’s enzymatic properties, holding out a lot of hope for engineering other forms of rubisco,” says Matthew Shoulders, the Class of 1942 Professor of Chemistry at MIT.

Shoulders and Robert Wilson, a research scientist in the Department of Chemistry, are the senior authors of the new study, which appears this week in the Proceedings of the National Academy of Sciences. MIT graduate student Julie McDonald is the paper’s lead author.

Evolution of efficiency

When plants or photosynthetic bacteria absorb energy from the sun, they first convert it into energy-storing molecules such as ATP. In the next phase of photosynthesis, cells use that energy to transform a molecule known as ribulose bisphosphate into glucose, which requires several additional reactions. Rubisco catalyzes the first of those reactions, known as carboxylation. During that reaction, carbon from CO₂ is added to ribulose bisphosphate.

Compared to the other enzymes involved in photosynthesis, rubisco is very slow, catalyzing only one to 10 reactions per second. Additionally, rubisco can also interact with oxygen, leading to a competing reaction that incorporates oxygen instead of carbon — a process that wastes some of the energy absorbed from sunlight.

“For protein engineers, that’s a really attractive set of problems because those traits seem like things that you could hopefully make better by making changes to the enzyme’s amino acid sequence,” McDonald says.

Previous research has led to improvement in rubisco’s stability and solubility, which resulted in small gains in enzyme efficiency. Most of those studies used directed evolution — a technique in which a naturally occurring protein is randomly mutated and then screened for the emergence of new, desirable features.

This process is usually done using error-prone PCR, a technique that first generates mutations in vitro (outside of the cell), typically introducing only one or two mutations in the target gene. In past studies on rubisco, this library of mutations was then introduced into bacteria that grow at a rate relative to rubisco activity. Limitations in error-prone PCR and in the efficiency of introducing new genes restrict the total number of mutations that can be generated and screened using this approach. Manual mutagenesis and selection steps also add more time to the process over multiple rounds of evolution.

The MIT team instead used a newer mutagenesis technique that the Shoulders Lab previously developed, called MutaT7. This technique allows the researchers to perform both mutagenesis and screening in living cells, which dramatically speeds up the process. Their technique also enables them to mutate the target gene at a higher rate.

“Our continuous directed evolution technique allows you to look at a lot more mutations in the enzyme than has been done in the past,” McDonald says.

Better rubisco

For this study, the researchers began with a version of rubisco, isolated from a family of semi-anaerobic bacteria known as Gallionellaceae, that is one of the fastest rubisco found in nature. During the directed evolution experiments, which were conducted in E. coli, the researchers kept the microbes in an environment with atmospheric levels of oxygen, creating evolutionary pressure to adapt to oxygen.

After six rounds of directed evolution, the researchers identified three different mutations that improved the rubisco’s resistance to oxygen. Each of these mutations are located near the enzyme’s active site (where it performs carboxylation or oxygenation). The researchers believe that these mutations improve the enzyme’s ability to preferentially interact with carbon dioxide over oxygen, which leads to an overall increase in carboxylation efficiency.

“The underlying question here is: Can you alter and improve the kinetic properties of rubisco to operate better in environments where you want it to operate better?” Shoulders says. “What changed through the directed evolution process was that rubisco began to like to react with oxygen less. That allows this rubisco to function well in an oxygen-rich environment, where normally it would constantly get distracted and react with oxygen, which you don’t want it to do.”

In ongoing work, the researchers are applying this approach to other forms of rubisco, including rubisco from plants. Plants are believed to lose about 30 percent of the energy from the sunlight they absorb through a process called photorespiration, which occurs when rubisco acts on oxygen instead of carbon dioxide.

“This really opens the door to a lot of exciting new research, and it’s a step beyond the types of engineering that have dominated rubisco engineering in the past,” Wilson says. “There are definite benefits to agricultural productivity that could be leveraged through a better rubisco.”

The research was funded, in part, by the National Science Foundation, the National Institutes of Health, an Abdul Latif Jameel Water and Food Systems Lab Grand Challenge grant, and a Martin Family Society Fellowship for Sustainability.

Other citizen science groups contributed as well, including the TESS Follow-up Observing Program Sub Group 1 (TFOP SG1) and the TESS Single Transit Planet Candidate (TSTPC) Working Group, making this a truly communal endeavor. Thanks to everyone’s combined efforts, astronomers were able to finally confirm the existence of TOI-4465b.

“The discovery and confirmation of TOI-4465 b not only expands our knowledge of planets in distant star systems but also shows how passionate astronomy enthusiasts can play a direct role in frontier scientific research,” said Dr. Zara Essack, Postdoctoral Fellow at the University of New Mexico and lead author of the study. “It’s a powerful example of citizen science, teamwork, and the importance of global collaboration in astronomy.”

This isn’t the first planet confirmed with help from the SETI & Unistellar Network, which is particularly well-suited for such discoveries.

“Now, people equipped with a digital smart telescope can observe and confirm exoplanets from their backyard, helping NASA map nearby planetary systems discovered by the TESS mission,” said Dr. Franck Marchis, Senior Astronomer at the SETI Institute and Chief Scientific Officer at Unistellar. “The likelihood of TESS observing another transit of a planet like TOI-4465 b, which happens only every 102 days, is low. So the SETI & Unistellar network is essential for these discoveries.”

TOI-4465 b represents an important piece of the planetary puzzle, helping bridge the gap between hot Jupiters that orbit close to their stars and our own Solar System’s cold gas giants. This new world is a “temperate” Jupiter: it shares some orbital properties with warm Jupiters, but its modest orbital eccentricity keeps its temperature relatively mild. TOI-4465 b is the most massive long-period giant known to transit a sub-solar metallicity star and has the largest radius of any known planet with an orbital period exceeding 100 days. As a result, it provides a unique test case for studying gas giants and helps fill gaps in our planetary knowledge.

“It’s really astounding what science can achieve when we work together,” said Dr. Lauren Sgro, Postdoctoral Fellow at the SETI Institute and co-author of the study. “I’m excited to see how future observations of this planet inform our understanding of gas giant formation, and knowing that citizen scientists are part of this process is truly inspiring.”

TOI-4465 b is also well-suited for follow-up studies of its atmosphere with instruments such as the James Webb Space Telescope, so this is only the beginning of its story. Perhaps the next chapter belongs to another new planet, waiting to be explored by professional and citizen astronomers alike.