Reporting in the Proceedings of the National Academy of Sciences, the team describes the discovery of “chemical fossils” preserved in rocks more than 541 million years old. These chemical fossils are traces of biological molecules once produced by living organisms that were later buried, altered, and locked into sediment for hundreds of millions of years.

The newly identified molecules belong to a group called steranes, which are stable remnants of sterols such as cholesterol that form part of the cell membranes of complex life. By analyzing their structure, the scientists linked these steranes to demosponges, a major group of sea sponges. Today, demosponges appear in many shapes, sizes, and colors and live throughout the world’s oceans as soft filter feeders. Their ancient relatives were likely similar in being soft bodied marine organisms.

“We don’t know exactly what these organisms would have looked like back then, but they absolutely would have lived in the ocean, they would have been soft-bodied, and we presume they didn’t have a silica skeleton,” says Roger Summons, the Schlumberger Professor of Geobiology Emeritus in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS).

The presence of these sponge specific chemical signatures strengthens the case that ancestors of demosponges were among the first animals to evolve, emerging well before most other major animal groups.

The research team includes lead author Lubna Shawar, a former MIT EAPS Crosby Postdoctoral Fellow who is now a research scientist at Caltech, along with Summons and colleagues Gordon Love of the University of California at Riverside, Benjamin Uveges of Cornell University, Alex Zumberge of GeoMark Research in Houston, Paco Cárdenas of Uppsala University in Sweden, and José Luis Giner of the State University of New York College of Environmental Science and Forestry.

Revisiting a 2009 Discovery in Precambrian Rocks

This work builds on a study the group first published in 2009. At that time, they analyzed rocks from an outcrop in Oman and detected an unusually high concentration of steranes derived from 30-carbon (C30) sterols. These rare steroid molecules appeared to originate from ancient sea sponges.

The rocks dated to the Ediacaran Period, which lasted from about 635 million to 541 million years ago, just before the Cambrian Period when complex multicellular life rapidly diversified. The earlier findings suggested that sponges existed long before the Cambrian explosion and may have been among the planet’s earliest animals.

Not everyone agreed. Some researchers proposed that the C30 steranes might have been produced by other organisms or even formed through nonbiological geological processes.

The new study adds weight to the sponge hypothesis. The team identified another distinctive chemical fossil in the same Precambrian rocks that is highly likely to have come from living organisms rather than from chemistry alone.

Rare Sterols and the Search for Early Animal Life

As in their previous investigations, the researchers examined Ediacaran age rocks collected from drill cores and outcrops in Oman, western India, and Siberia. They searched for steranes, which are stable versions of sterols found in all eukaryotes (plants, animals, and any organism with a nucleus and membrane-bound organelles).

“You’re not a eukaryote if you don’t have sterols or comparable membrane lipids,” Summons says.

Sterols share a core structure made of four connected carbon rings. Different organisms modify that structure by adding carbon side chains and other chemical groups, depending on the genes they carry. In humans, cholesterol contains 27 carbon atoms, while plant sterols typically contain 29.

“It’s very unusual to find a sterol with 30 carbons,” Shawar says.

The earlier research had identified a 30-carbon sterol tied to a specific enzyme encoded by a gene common in demosponges. In the new analysis, the team realized that the same gene could also produce an even rarer 31-carbon sterol (C31). When they reexamined their rock samples, they detected abundant C31 steranes alongside the previously identified C30 forms.

“These special steranes were there all along,” Shawar says. “It took asking the right questions to seek them out and to really understand their meaning and from where they come.”

Laboratory Tests Confirm Biological Origin

To confirm the source, the scientists studied living demosponges and found that some species produce C31 sterols, the biological precursors of the C31 steranes preserved in rock. They then synthesized eight different C31 sterols in the laboratory to serve as reference compounds. After subjecting these molecules to conditions that mimic burial and geological transformation over millions of years, they compared the results with the ancient samples.

Only two of the eight synthesized sterols transformed into compounds that matched the C31 steranes found in the rocks. The absence of the other six products indicates that the molecules were not created by random chemical reactions in the environment.

Together, evidence from rock chemistry, modern sponges, and laboratory experiments supports the conclusion that the steranes originated from living organisms. Those organisms were most likely early ancestors of demosponges, which still retain the ability to produce similar compounds today.

“It’s a combination of what’s in the rock, what’s in the sponge, and what you can make in a chemistry laboratory,” Summons says. “You’ve got three supportive, mutually agreeing lines of evidence, pointing to these sponges being among the earliest animals on Earth.”

“In this study we show how to authenticate a biomarker, verifying that a signal truly comes from life rather than contamination or non-biological chemistry,” Shawar adds.

Expanding the Search for the First Animals

Now that C30 and C31 sterols appear to be reliable indicators of ancient sponges, the researchers plan to examine rocks from other parts of the world. So far, the samples indicate that these sponges lived during the Ediacaran Period. With additional material, the team hopes to pinpoint more precisely when some of the earliest animals first emerged.

This research was supported, in part, by the MIT Crosby Fund, the Distinguished Postdoctoral Fellowship program, the Simons Foundation Collaboration on the Origins of Life, and the NASA Exobiology Program.

Toward the end of its mission, Cassini measured how mass is distributed inside Saturn. That internal structure controls the planet’s slow wobble in space, known as precession. For many years, researchers believed Saturn’s precession matched Neptune’s, allowing their gravitational interactions to gradually tilt Saturn and make its rings more visible from Earth.

However, Cassini’s final measurements revealed that Saturn’s mass is more concentrated toward its center than scientists had expected. This subtle difference changes Saturn’s precession rate so that it no longer aligns with Neptune’s. To account for the mismatch, researchers at MIT and UC Berkeley proposed that Saturn once had an additional moon. According to their idea, that moon was flung away after a close encounter with Titan and later broke apart, creating the rings.

Hyperion’s Orbit Offers a Clue

The SETI Institute team tested whether such an extra moon could have moved close enough to Saturn to form the rings. Computer simulations showed that the most likely outcome was not ring formation directly, but a collision between the extra moon and Titan.

An important clue comes from Hyperion, Saturn’s small, irregularly shaped moon that tumbles chaotically in space. Hyperion’s orbit is locked with Titan’s.

“Hyperion, the smallest among Saturn’s major moons provided us the most important clue about the history of the system,” said Ćuk. “In simulations where the extra moon became unstable, Hyperion was often lost and survived only in rare cases. We recognized that the Titan-Hyperion lock is relatively young, only a few hundred million years old. This dates to about the same period when the extra moon disappeared. Perhaps Hyperion did not survive this upheaval but resulted from it. If the extra moon merged with Titan, it would likely produce fragments near Titan’s orbit. That is exactly where Hyperion would have formed.”

In other words, Hyperion may not have simply survived past chaos. It may have formed from debris created when Titan merged with another moon.

A Collision Between Proto Moons

The new model proposes that Titan formed when two earlier moons combined. One was a large body called “Proto-Titan,” nearly as massive as Titan today. The other was a smaller companion referred to as “Proto-Hyperion.”

Such a merger could explain why Titan has relatively few impact craters. A massive collision would have resurfaced the moon, erasing much of its earlier crater record. Titan’s current orbit, which is slightly elongated but gradually becoming more circular, also hints at a relatively recent disturbance consistent with a past merger.

Before the collision, Proto-Titan may have resembled Jupiter’s moon Callisto, heavily cratered and lacking an atmosphere. The team also found that before it disappeared, Proto-Hyperion could have tilted the orbit of Saturn’s distant moon Iapetus, potentially solving another longstanding mystery about the Saturn system.

How Titan’s Merger May Have Created Saturn’s Rings

If Titan formed from a moon merger, the question remains: where did Saturn’s rings come from?

More than a decade ago, members of the SETI Institute team suggested that the rings formed from debris created when medium sized moons closer to Saturn collided. Later simulations by researchers at the University of Edinburgh and NASA Ames Research Center supported this idea. Those studies showed that most of the debris from such impacts would eventually clump back together into moons, but some material would be scattered inward and remain as rings.

Previously, scientists believed the Sun may have triggered the instability that caused those inner moon collisions. The new research suggests a different chain of events. Titan’s merger may have set off the process.

Titan’s slightly elongated orbit can disturb inner moons when their orbital periods become simple fractions of Titan’s. This configuration, known as orbital resonance, strengthens gravitational interactions. Although such alignments are unlikely at any given moment, Titan’s outward migration sometimes creates these resonances.

When that happens, smaller moons can be pushed into more stretched out orbits, increasing the chances that they collide with neighboring moons. The timing of this second round of destruction is uncertain, but it must have occurred after Titan’s merger. That sequence fits with estimates that Saturn’s rings are about 100 million years old.

Dragonfly Mission Could Test the Theory

NASA’s Dragonfly mission, scheduled to arrive at Titan in 2034, could provide crucial evidence. The nuclear powered octocopter will study Titan’s surface geology and chemistry in detail. If Dragonfly finds signs of large scale resurfacing or other clues tied to a massive collision about half a billion years ago, it would support the idea that Titan was shaped by a dramatic moon merger.

The study has been accepted for publication in the Planetary Science Journal, and the preprint is available on arXiv.

Led by Jie V. Zhao, Yitang Sun, Junmeng Zhang, and Kaixiong Ye from the University of Hong Kong and the University of Georgia, the research team focused on phenylalanine and tyrosine. Their findings suggest that higher tyrosine levels are associated with shorter life expectancy in men, raising the possibility that longevity strategies may need to differ by sex.

Amino Acids, Brain Function, and Aging

Phenylalanine and tyrosine are amino acids that play important roles in metabolism and brain activity. They are naturally present in protein rich foods and are also sold as dietary supplements. Despite their widespread use, scientists still do not fully understand how these compounds may affect the aging process over time.

Tyrosine is especially notable because it helps produce neurotransmitters such as dopamine, which influence mood, motivation, and cognitive performance. Because of its role in brain chemistry, tyrosine has drawn increasing interest in aging research.

Large UK Biobank Study Examines Lifespan

To investigate potential links to longevity, the researchers analyzed health and genetic data from more than 270,000 participants in the UK Biobank. They used both observational data and genetic techniques to assess whether blood levels of phenylalanine and tyrosine were related to overall mortality and predicted lifespan.

At first, both amino acids appeared to be associated with a higher risk of death. However, after deeper analysis, only tyrosine showed a consistent and potentially causal relationship with reduced life expectancy in men. Genetic modeling suggested that men with elevated tyrosine levels could live nearly one year less on average. No meaningful association was found in women.

The connection remained even after accounting for other related factors, including phenylalanine. This strengthens the possibility that tyrosine itself may independently influence aging. Researchers also noted that men generally have higher tyrosine levels than women, which may help explain part of the longstanding lifespan gap between the sexes.

“Phenylalanine showed no association with lifespan in either men or women after controlling for tyrosine.”

Possible Biological Explanations

Scientists are still working to understand why tyrosine might affect lifespan in men. One possibility involves insulin resistance, a condition linked to many age related diseases. Tyrosine is also involved in producing stress related neurotransmitters, which may influence metabolic and hormonal pathways differently in men and women. Variations in hormone signaling could help explain why the effect appeared only in men.

Supplement Use and Longevity Questions

Tyrosine is often marketed as a supplement to improve focus and mental performance. Although this study did not directly test tyrosine supplements, the findings raise questions about its long term impact on health and lifespan.

The researchers suggest that individuals with high tyrosine levels might benefit from dietary adjustments. Approaches such as moderating overall protein intake could potentially lower tyrosine levels and support healthier aging.

More research will be needed to confirm these results and to determine whether changes in diet or lifestyle can safely reduce tyrosine levels and promote longer life.

New research led by the University of Colorado Boulder and published in Nature Geoscience explains what happened in 2023, when the glacier lost about eight kilometers of ice in just 60 days. The study found that the key factor was the flat bedrock beneath the glacier. As the ice thinned, this smooth foundation allowed large sections to lift off the ground and float, triggering an unusual and sudden calving event.

The findings could help scientists pinpoint other Antarctic glaciers that might be vulnerable to similar rapid collapse. Hektoria Glacier is relatively small by Antarctic standards, covering about 115 square miles, roughly the size of Philadelphia. However, if a much larger glacier were to retreat this quickly, the consequences for global sea level rise could be severe.

“When we flew over Hektoria in early 2024, I couldn’t believe the vastness of the area that had collapsed,” said Naomi Ochwat, lead author and CIRES postdoctoral researcher. “I had seen the fjord and notable mountain features in the satellite images, but being there in person filled me with astonishment at what had happened.”

Satellite Data Revealed a Sudden Collapse

Ochwat and her colleagues, including CIRES Senior Research Scientist Ted Scambos, were initially studying the region for a different project. They were investigating why sea ice detached from a glacier years after a nearby ice shelf broke apart in 2002.

While reviewing satellite and remote sensing data, Ochwat noticed something unexpected. The images showed that Hektoria Glacier had retreated dramatically within a short window of time. That discovery led her to focus on a pressing question: why did this glacier collapse so quickly?

Ice Plain Topography and Grounding Lines

Many Antarctic glaciers are tidewater glaciers, meaning they sit on the ocean floor and extend into the sea, where they release icebergs. The landscape beneath them can vary widely. Some rest over deep troughs or underwater mountains, while others lie across broad, flat plains.

Hektoria sat on what scientists call an ice plain, a flat stretch of bedrock below sea level. Geological evidence shows that between 15,000-19,000 years ago, glaciers positioned over similar ice plains retreated at extraordinary speeds, sometimes moving back hundreds of meters per day. That historical insight helped researchers interpret what they were seeing at Hektoria.

When a tidewater glacier thins enough, it can lift off the seabed and begin floating on the ocean surface. The location where it transitions from grounded to floating ice is known as the grounding line. By analyzing multiple satellite datasets, the team identified several grounding lines at Hektoria, a sign of ice plain conditions beneath the glacier.

Rare Calving Process Triggered Rapid Ice Loss

Because the glacier rested on a flat bed, large portions were able to lift off almost at once. Once afloat, the ice was exposed to powerful ocean forces. Cracks opened along the base of the glacier and eventually connected with fractures at the surface. This chain reaction caused extensive calving, breaking apart nearly half the glacier in a matter of weeks.

By combining frequent satellite observations, the researchers reconstructed the sequence of events in detail.

“If we only had one image every three months, we might not be able to tell you that the glacier lost two and a half kilometers in two days,” Ochwat said. “Combining these different satellites, we can fill in time gaps and confirm how quickly the glacier lost ice.”

Glacier Earthquakes Confirmed Ice Loss

The team also deployed seismic instruments that detected a series of glacier earthquakes during the period of rapid retreat. These tremors confirmed that the glacier had been firmly grounded on bedrock before lifting off. The data not only verified the presence of an ice plain but also showed that the ice loss directly contributed to rising global sea levels.

Ice plains have been identified beneath many other Antarctic glaciers. Understanding how they influence retreat rates will help scientists better forecast which glaciers might be prone to sudden collapse in the future.

“Hektoria’s retreat is a bit of a shock — this kind of lighting-fast retreat really changes what’s possible for other, larger glaciers on the continent,” Scambos said. “If the same conditions set up in some of the other areas, it could greatly speed up sea level rise from the continent.”

Their findings appear in a review published in Nature Photonics, which examines the rapid advances in creating, controlling, and measuring structured quantum light. The paper highlights a growing set of powerful tools, including on-chip integrated photonics, nonlinear optics, and multiplane light conversion. Together, these methods are transforming structured quantum states from laboratory concepts into practical systems for imaging, sensing, and quantum networks.

From Empty Toolbox to Advanced Quantum Control

Professor Andrew Forbes of Wits University, the study’s corresponding author, says the transformation in this field over the past 20 years has been remarkable. “The tailoring of quantum states, where quantum light is engineered for a particular purpose, has gathered pace of late, finally starting to show its full potential. Twenty years ago the toolkit for this was virtually empty. Today we have on-chip sources of quantum structured light that are compact and efficient, able to create and control quantum states.”

A major advantage of shaping photons is that it allows researchers to use high-dimensional encoding alphabets. In simple terms, each photon can carry more information and resist interference more effectively. That makes structured quantum light especially attractive for secure quantum communication systems.

Challenges in Long-Distance Quantum Communication

Despite the progress, real-world conditions still pose obstacles. Certain communication channels are not well suited for spatially structured photons, which limits how far these signals can travel compared to more traditional properties such as polarisation. “Although we have made amazing progress, there are still challenging issues,” says Forbes. “The distance reach with structured light, both classical and quantum, remains very low … but this is also an opportunity, stimulating the search for more abstract degrees of freedom to exploit.”

To address this limitation, researchers are exploring ways to give quantum states topological properties. Topological features can make quantum information more stable against disturbances. “We have recently shown how quantum wave functions naturally have the potential to be topological, and this promises the preservation of quantum information even if the entanglement is fragile,” says Forbes.

Multidimensional Entanglement and Future Applications

The review also outlines fast-moving developments in multidimensional entanglement, ultrafast temporal structuring, advanced nonlinear detection techniques, and compact on-chip devices that can generate or process higher-dimensional quantum light than ever before. These breakthroughs are paving the way for high-resolution quantum imaging, extremely precise measurement tools, and quantum networks capable of transmitting more data through multiple interconnected channels.

Overall, the field appears to be reaching a pivotal moment. Researchers believe quantum optics based on structured light is poised for major growth, with the future looking “very bright indeed” — but additional work is required to increase dimensionality, raise photon output, and design quantum states that can withstand realistic optical environments.