The atmosphere of Earth during the Mesozoic era, between 252 and 66 million years ago, contained far more carbon dioxide than it does today and total photosynthesis from plants around the world was twice as high as it is today, according to an analysis of oxygen isotope composition of dinosaur teeth.
The fossilized teeth of Camarasaurus from the Morrison Formation in the United States. Image credit: Sauriermuseum Aathal.
In the study, Dr. Dingsu Feng from the University of Göttingen and colleagues analyzed the dental enamel of dinosaurs that lived in North America, Africa and Europe during the Late Jurassic and Late Cretaceous periods.
“Enamel is one of the most stable biological materials,” they said.
“It records different isotopes of oxygen that the dinosaurs inhaled with every breath that they took.”
“The ratio of isotopes in oxygen is affected by changes in atmospheric carbon dioxide and photosynthesis by plants.”
“This correlation allows us to draw conclusions about the climate and vegetation during the age of the dinosaurs.”
“In the Late Jurassic period, around 150 million years ago, the air contained around four times as much carbon dioxide as it did before industrialization — that is, before humans started emitting large quantities of greenhouse gases into the atmosphere.”
“And in the Late Cretaceous period, around 73 to 66 million years ago, the level was three times as high as today.”
Individual teeth from two dinosaur species — Tyrannosaurus rex and Kaatedocus siberi — contained a strikingly unusual composition of oxygen isotopes.
This points to carbon dioxide spikes that could be linked to major events such as volcanic eruptions — for example, the massive eruptions of the Deccan Traps in what is now India, which happened at the end of the Cretaceous period.
The fact that plants on land and in water around the world were carrying out more photosynthesis at that time was probably associated with carbon dioxide levels and higher average annual temperatures.
This study marks a milestone for paleoclimatology: until now, carbonates in the soil and marine proxies were the main tools used to reconstruct the climate of the past.
Marine proxies are indicators, such as fossils or chemical signatures in sediments, that help scientists understand environmental conditions in the sea in the past. However, these methods are subject to uncertainty.
“Our method gives us a completely new view of the Earth’s past,” Dr. Feng said.
“It opens up the possibility of using fossilized tooth enamel to investigate the composition of the early Earth’s atmosphere and the productivity of plants at that time.”
“This is crucial for understanding long-term climate dynamics.”
“Dinosaurs could be the new climate scientists. Long ago their teeth recorded the climate for a period of over 150 million years — finally we are getting the message.”
The study was published August 4, 2025 in the Proceedings of the National Academy of Sciences.
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Dingsu Feng et al. 2025. Mesozoic atmospheric CO2 concentrations reconstructed from dinosaur tooth enamel. PNAS 122 (33): e2504324122; doi: 10.1073/pnas.2504324122
Scientists examining samples from the asteroid Bennu are discovering some of it is made up of what astronomers call “stardust.”
University of Arizona planetary scientist Jessica Barnes explains that means Bennu was formed by at least one collision with another, larger asteroid during the earliest moments of our solar system.
“These are very, very tiny grains of dust that originate around other stars and we can identify them in the sample because they look completely unlike anything in our solar system,” she said.
The samples were brought to Earth by the UA-backed OSIRIS-REx mission. Barnes says Bennu also showed signs being blasted by micrometeorite impacts during its 4-point-6-billion-year history.
The material was examined using instruments from UA’s Kuiper-Arizona Laboratory for Astromaterials Analysis. That’s a tool that can reveal a sample’s chemical elements at nanometer scale.
The International Space Station (ISS) has been in orbit for over 26 years, housing astronauts at an altitude of 250 miles (400 kilometers) above Earth. But even at that distance, the space station can’t escape the drag of Earth’s atmosphere as oxygen molecules and other gases collide with it, causing it to lose altitude over time.
For the ISS to retain its status in orbit, NASA and its partners perform the occasional reboost maneuver. This is typically done using the space station’s own thrusters (which are tiny and relatively weak) or with Russia’s Progress spacecraft and Northrop Grumman’s Cygnus. For the first time, however, and starting in September, NASA will use SpaceX’s Dragon vehicle to help sustain the space station’s orbital altitude.
A boost kit in the trunk
SpaceX’s Dragon launched to the ISS on Sunday at 2:45 a.m. ET, carrying more than 5,000 pounds of supplies to the orbiting lab. The otherwise routine commercial resupply mission carried a little something extra this time around, a propellant system tucked inside Dragon’s trunk for a reboost demonstration.
Dragon’s boost kit will be used to maintain the altitude of the ISS starting in September through a series of burns planned throughout the fall, nudging the massive space station a little higher in its orbit.
The SpaceX spacecraft, while docked to the station, will use a propellant system that’s independent from the one used to fuel its own engines. Instead, the boost kit fuels two Draco engines in the spacecraft’s trunk using an existing hardware and propellant system design, according to NASA.
Dragon’s engines are not facing the right direction to pull off the boost maneuvers; hence, the need for the additional engines that are aligned with the velocity vector of the ISS.
The rear-facing engines are connected to propellant tanks filled with hydrazine and nitrogen tetroxide, which ignite when they come in contact with one another. When it’s time to give the ISS a little boost, the engines will ignite and lightly adjust the space station’s altitude in low Earth orbit.
Multiple reboost options
NASA and SpaceX tested Dragon’s ability to reboost the ISS in November 2024 through a demonstration that lasted approximately 12 minutes. Dragon successfully adjusted the station’s orbit by 7/100 of a mile at apogee, the point at which it’s farthest away from Earth, and 7/10 of a mile at perigee, when it is closest to Earth.
“By testing the spacecraft’s ability to provide reboost and, eventually, attitude control, NASA’s International Space Station Program will have multiple spacecraft available to provide these capabilities for the orbital complex,” NASA wrote in a statement at the time.
The Dragon spacecraft will remain docked to the ISS until December—the longest period for a cargo mission—in order to pull off the reboost maneuvers in the coming months. The boost kit being used on this mission is a smaller version of one SpaceX is currently developing for the space station’s final deorbit.
The ISS is due to retire by 2030, and NASA plans on using a Dragon spacecraft to perform a series of deorbit burns that will lower the space station’s altitude until it burns up in Earth’s atmosphere. Until the moment comes for its impending doom, the ISS will get to enjoy a little boost from Dragon.
Ceres, the largest object in the asteroid belt between Mars and Jupiter, has long been cast as a frozen relic of the early solar system — quiet, airless, and lifeless. But new research suggests that billions of years ago, this dwarf planet may have harbored the right ingredients to support simple microbial life.
That’s according to a new study using data from NASA’s Dawn spacecraft that opens the door to reevaluating the habitability of similarly small, icy bodies in the solar system, scientists say. If Ceres ever was habitable, its window to potentially sustain life likely closed billions of years ago. Today, its surface is bitterly cold, with most of its underground water frozen into a thick shell of ice, with some remaining as a salty brine trapped below.
Yet data gathered by Dawn revealed hints of a more dynamic, complex past. Bright, reflective patches on the surface turned out to be salt deposits left by briny liquid that once seeped upward. Organic molecules, discovered in Ceres’ soil, suggest the ingredients for life were also present. Until now, though, one piece was missing: a source of energy to sustain life.
A world gone cold
Ceres is small by planetary standards, measuring just 600 miles (960 kilometers) across, or about one-third the width of Earth’s moon. Unlike icy moons such as Jupiter’s Europa and Saturn’s Enceladus, which are kept warm by the gravitational tug of giant planets, Ceres has no external energy source to prolong its habitability.
The new study fills that gap, scientists say. Using computer models, researchers simulated Ceres’ interior over billions of years and found that, between 2.5 and 4 billion years ago, radioactive decay in the dwarf planet’s rocky core could have generated enough heat to drive hydrothermal activity.
Circulating water within the planet would have reacted with hot, altered rock, carrying gases and minerals into a global ocean, creating chemical “food” for microbes — much like the hydrothermal vents that teem with life on Earth’s sunless seafloor, according to the new study.
“On Earth, when hot water from deep underground mixes with the ocean, the result is often a buffet for microbes — a feast of chemical energy,” Samuel Courville, a researcher at Arizona State University who led the new study, said in a statement. “So it could have big implications if we could determine whether Ceres’ ocean had an influx of hydrothermal fluid in the past.”
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An illustration of the interior of dwarf planet Ceres, showing how water and gases can flow from its rocky core to a reservoir of salty water. (Image credit: NASA/JPL-Caltech)
Even if life never took hold on Ceres, the discovery could help broaden the range of environments that could potentially be habitable. Unlike many ocean worlds orbiting giant planets, Ceres isn’t powered by tidal heating, making it a simpler and more revealing case study of how small, icy bodies evolve. Because so many objects in the solar system are similar in size, researchers suggest they could have represented a common type of habitable environment in the solar system’s early days.
The study also points to other candidates: icy worlds roughly the size of Ceres, including some moons of Uranus and Saturn, may have followed comparable evolutionary paths and hosted temporary oceans capable of supporting life before cooling into the frozen landscapes we see today.
A study of potential past habitability on Ceres was published on Aug. 20 in the journal Science Advances.
A team of astronomers has detected for the first time a growing planet outside our solar system, embedded in a cleared gap of a multi-ringed disk of dust and gas.
The team, led by University of Arizona astronomer Laird Close and Richelle van Capelleveen, an astronomy graduate student at Leiden Observatory in the Netherlands, discovered the unique exoplanet using the University of Arizona’s MagAO-X extreme adaptive optics system at the Magellan Telescope in Chile, the U of A’s Large Binocular Telescope in Arizona and the Very Large Telescope at the European Southern Observatory in Chile. Their results are published in The Astrophysical Journal Letters.
In this artist’s illustration, infalling hydrogen gas causes the growing protoplanet WISPIT 2b to shine brightly in the hydrogen alpha spectrum, to which the MagAO-X instrument is particularly sensitive.
Joseph Olmsted/STScI/NASA
For years, astronomers have observed several dozen planet-forming disks of gas and dust surrounding young stars. Many of these disks display gaps in their rings, hinting at the possibility that they are being “plowed” by nearby nascent planets, or protoplanets, like lanes being cleared by a snowplow. Yet, only about three actual young growing protoplanets have been discovered to date, all in the cavities between a host star and the inner edge of its adjacent protoplanetary disk. Until this discovery, no protoplanets had been seen in the conspicuous disk gaps – which appear as dark rings.
“Dozens of theory papers have been written about these observed disk gaps being caused by protoplanets, but no one’s ever found a definitive one until today,” said Close, professor of astronomy at the University of Arizona. He calls the discovery a “big deal,” because the absence of planet discoveries in places where they should be has prompted many in the scientific community to invoke alternative explanations for the ring-and-gap pattern found in many protoplanetary disks.
“It’s been a point of tension, actually, in the literature and in astronomy in general, that we have these really dark gaps, but we cannot detect the faint exoplanets in them,” he said. “Many have doubted that protoplanets can make these gaps, but now we know that in fact, they can.”
4.5 billion years ago, our solar system began as just such a disk. As dust coalesced into clumps, sucking up gas around them, the first protoplanets began to form. How exactly this process unfolded, however, is still largely a mystery. To find answers, astronomers have looked to other planetary systems that are still in their infancy, known as planet-forming disks, or protoplanetary disks.
The U of A-built MagAO-X instrument in the clean room at the Magellan Telescope in Chile.
Close’s team took advantage of an adaptive optics system, one of the most formidable of its kind in the world, developed and built by Close, Jared Males and their students. Males is an associate astronomer at Steward Observatory and the principal investigator of MagAO-X. MagAO-X, which stands for “Magellan Adaptive Optics System eXtreme,” dramatically improves the sharpness and resolution of telescope images by compensating for atmospheric turbulence, the phenomenon that causes stars to flicker and blur, and is dreaded by astronomers.
Suspecting there should be invisible planets hiding in the gaps of protoplanetary disks, Close’s team surveyed all the disks with gaps and probed them for a specific emission of visible light known as hydrogen alpha or H-alpha.
“As planets form and grow, they suck in hydrogen gas from their surroundings, and as that gas crashes down on them like a giant waterfall coming from outer space and hits the surface, it creates extremely hot plasma, which in turn, emits this particular H-alpha light signature,” Close explained. “MagAO-X is specially designed to look for hydrogen gas falling onto young protoplanets, and that’s how we can detect them.”
The team used the 6.5-meter Magellan Telescope and MagAO-X to probe WISPIT-2, a disk van Capelleveen recently discovered with the VLT. Viewed in H-alpha light, Close’s group struck gold. A dot of light appeared inside the gap between two rings of the protoplanetary disk around the star. In addition, the team observed a second candidate planet inside the “cavity” between the star and the inner edge of the dust and gas disk.
“Once we turned on the adaptive optics system, the planet jumped right out at us,” said Close, who called this one of the more important discoveries in his career. “After combining two hours’ worth of images, it just popped out.”
According to Close, the planet, designated WISPIT 2b, is a very rare example of a protoplanet in the process of accreting material onto itself. Its host star, WISPIT 2 is similar to the sun and about the same mass. The inner planet candidate, dubbed CC1, contains about nine Jupiter masses, whereas the outer planet, WISPIT 2b, weighs in at about five Jupiter masses. These masses were inferred, in part, from the thermal infrared light observed by the University of Arizona’s 8.4-meter Large Binocular Telescope on Mount Graham in Southeastern Arizona with the help of U of A astronomy graduate student Gabriel Weible.
“It’s a bit like what our own Jupiter and Saturn would have looked like when they were 5,000 times younger than they are now,” Weible said. “The planets in the WISPIT-2 system appear to be about 10 times more massive than our own gas giants and more spread out. But the overall appearance is likely not so different from what a nearby ‘alien astronomer’ could have seen in a ‘baby picture’ of our solar system taken 4.5 billion years ago.”
“Our MagAO-X adaptive optics system is optimized like no other to work well at the H-alpha wavelength, so you can separate the bright starlight from the faint protoplanet,” Close said. “Around WISPIT 2 you likely have two planets and four rings and four gaps. It’s an amazing system.”
CC1 might orbit at about 14-15 astronomical units – with one AU equaling the average distance between the sun and Earth, which would place it halfway between Saturn and Uranus, if it was part of our solar system, according to Close. WISPIT-2b, the planet carving out the gap, is farther out at about 56 AU, which in our own solar system, would put it well past the orbit of Neptune, around the outer edge of the Kuiper Belt.
A second paper published in parallel and led by van Capelleveen and the University of Galway details the detection of the planet in the infrared light spectrum and the discovery of the multi-ringed system with the 8-meter VLT telescope’s SPHERE adaptive optics system.
“To see planets in the fleeting time of their youth, astronomers have to find young disk systems, which are rare,” van Capelleveen said, “because that’s the one time that they really are brighter and so detectable. If the WISPIT-2 system was the age of our solar system and we used the same technology to look at it, we’d see nothing. Everything would be too cold and too dark.”
This research was supported in part by a grant from the NASA eXoplanet Research Program. MagAO-X was developed in part by a grant from the U.S. National Science Foundation and by the generous support of the Heising-Simons Foundation.
Volcanoes can bring catastrophic consequences, and reliable warnings can make the difference between a close call and a tragedy.
A new study on Japan’s Ontake Volcano identifies a signal, in the form of a subtle change in earthquake waves, that could sharpen those warnings.
Researchers compared two eruptions of Ontake and focused on a detail in the waves that ripple through stressed rock.
The study was led by Professor Mike Kendall of the Department of Earth Sciences at the University of Oxford.
What the volcano signal shows
Scientists track a pattern in earthquake waves called shear-wave splitting, which appears when the same wave separates into a fast twin and a slow twin as it passes through cracked, stressed rock.
The effect is a form of seismic anisotropy, and changes in the timing of that effect have been documented around eruptions at different volcanoes for decades.
Because cracks tend to align with local stress, tracking the split and the direction of the fast wave shows how stress changes underground. That makes the signal a practical way to watch a volcano’s plumbing without digging a hole.
Mapping these changes does not replace other tools – it complements them. It can bring clarity when other signals are messy or missing.
Tale of two volcanic eruptions
Mount Ontake erupted on September 27, 2014, killing at least 58 hikers and marking Japan’s deadliest volcanic disaster since 1926. A smaller event in late March, 2007, produced far less impact and activity.
Steam driven blasts, known as a phreatic eruption, can start fast and with few surface clues, which explains why Ontake 2014 surprised so many people.
In the weeks leading up to 2014, seismologists detected small quakes beneath the summit, but other classic signs were muted. That context makes a clean, measurable stress signal especially valuable to public safety.
Volcano signals change
The Ontake team found that readings from 12 monitoring stations showed a sudden shift when the 2014 eruption began.
Small delays in the seismic waves nearly doubled, and the signal strength jumped from about 3 percent to 20 percent, with the main direction of stress in the rock also shifting.
These changes suggest that cracks in the volcano’s system of hot water and steam opened quickly as pressure built up, forcing the rock to break in new ways. Nothing similar showed up during the 2007 activity, which stayed mild.
The study also points out the big difference in eruption size: a very small event in 2007 compared with a much larger one in 2014, which matched the stronger seismic signal.
“The focal mechanisms of volcano-tectonic earthquakes changed drastically before and after the 2014 eruption,” said Professor Toshiko Terakawa of Nagoya University.
“Integrating data from shear-wave splitting and earthquake focal mechanisms could provide deeper insights into conditions required for an eruption to occur,” she added.
The analyses of focal mechanisms, which describe how faults move during quakes, added another layer of evidence.
Predicting eruptions saves lives
A parameter that jumps when stress crosses a threshold is the kind of signal that can build confidence. It is clear, it has a size, and it ties directly to physics in the rock.
“The records around two eruptions on Ontake volcano in Japan have been able to show that the method can not only show changes before eruptions, but that they can potentially help to predict the size of an eruption,” said Professor Martha Savage of Victoria University of Wellington (VUW).
Emergency managers care about false alarms because trust erodes when communities evacuate for nothing. A detectable change in how cracks line up can reduce risk by pointing to real shifts in pressure inside the volcano.
Local monitoring teams can add this volcano signal tool to networks that already track ground tilt, gas, and tremor. It slots into existing workflows and draws on the same earthquakes that many stations already record.
What comes next
Every volcano has its own structure and history, so thresholds will need local calibration. That work takes time, but it is a straightforward path that builds on current instrumentation.
Results from other volcanoes have shown that splitting can track stress through time, which sets the stage for operations that watch for sudden increases rather than subtle drifts. That change in approach can matter when decisions must be made quickly.
“We expect to see these effects at other volcanoes across the globe, not just at Ontake Volcano,” said Dr. Tom Kettlety of the University of Oxford. The team expects broader use beyond Ontake as more stations apply the method.
As with all warning tools, clarity begins with solid evidence and honest communication. Splitting, used alongside other lines of data, can help alerts land with the weight they deserve.
The study is published in Seismica.
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Scientists have hacked the rules of light–matter interaction to spot disease earlier than ever before.
A Johns Hopkins team has unveiled a novel way to observe molecular vibrations, using light to create hybrid states with molecules that expose even the faintest signals.
The breakthrough, led by mechanical engineering professor Ishan Barman, could transform early disease detection, ranging from infections and metabolic disorders to cancer.
Molecular vibrations are tiny, unique movements of atoms within a molecule, which offer chemical “fingerprints” with unprecedented clarity.
Rewiring light for health
In healthcare, the method could enable earlier, more accurate detection of disease biomarkers in blood, saliva, or urine.
Beyond medicine, it may also transform pharmaceutical manufacturing by allowing real-time monitoring of complex chemical reactions, ensuring consistency and safety. Environmental scientists could use it to detect pollutants or hazardous compounds at trace levels with unprecedented reliability.
Techniques like infrared and Raman spectroscopy are often used to detect these vibrations, but their signals are faint, easily lost in background noise, and difficult to isolate in complex environments such as blood or tissue.
“We were trying to overcome a long-standing challenge in molecular sensing: How do you make optical detection of molecules more sensitive, more robust, and more adaptable to real-world conditions?” said Barman.
“Rather than trying to incrementally improve conventional methods, we asked a more radical question: What if we could re-engineer the very way light interacts with matter to create a fundamentally new kind of sensing?”
Using highly reflective gold mirrors to form an optical cavity, the team trapped the light, bouncing it back and forth to enhance its interaction with the enclosed molecules. As a result, the confined light field and molecular vibrations formed entirely new quantum states called “vibro-polaritons.”
Quantum sensing goes real
The team achieved this under normal, real-world conditions without relying on high-vacuum, cryogenic, or other extreme setups usually needed to preserve fragile quantum states.
Lead author Peng Zheng, an associate research scientist in mechanical engineering at Johns Hopkins, said the work turns “quantum vibro-polaritonic sensing” from a concept into a working platform, paving the way for a new class of quantum-enabled optical sensors.
“Rather than passively detecting molecules, we can now engineer the quantum environment around them to selectively enhance their optical fingerprints by utilizing the quantum vibro-polaritonic states,” said Zheng.
By applying quantum principles in a new way, without relying on bulky traditional infrastructure, the study marks a major step forward for ambient-condition quantum technologies. Barman envisions the approach leading to compact, chip-scale devices that could power portable diagnostic tools and AI-driven medical testing.
“The future of quantum sensing isn’t stuck in the lab—it’s poised to make a real-world impact across medicine, biomanufacturing, and beyond,” Barman said.
The work was supported by the National Institute of General Medical Sciences, with Steve Semancik, a physicist at the National Institute of Standards and Technology (NIST), serving as co-author.
One of three rockets for the TOMEX+ mission sits on a launcher at Wallops Flight Facility in Virginia. U.S. citizens in the mid-Atlantic region may catch a weather-permitted glimpse Tuesday night of NASA’s launch of its mission to launch a TOMEX+ sounding rocket in its second attempt, according to NASA. Photo by Danielle Johnson/NASA
Aug. 26 (UPI) — NASA has set Tuesday for its next launch attempt of its TOMEX+ sounding rocket mission to take a peak at the Earth’s atmosphere.
U.S. citizens in the mid-Atlantic region may catch a weather-permitted glimpse Tuesday night of NASA’s launch of its mission to launch a TOMEX+ sounding rocket in its second attempt, according to NASA.
The live-streamed launch is targeted in a window anywhere from 10:30 p.m. EDT to 3:30 a.m.
On Wednesday, NASA announced its TOMEX+ plan that looks to study the turbulence where Earth’s atmosphere ends and outer space begins.
Tuesday’s launch attempt comes after repeated other launch attempts.
Sounding rockets are those that can be aimed to reach the Earth’s mesopause, an area of the atmosphere that’s too high for weather balloons and too low for traditional satellites to reach.
