Category: 7. Science

It had been thought that a colossal collision with an early planet containing half of Jupiter’s core material could have mixed up the central region of the gas giant, enough to explain its interior today.

But a new study published in Monthly Notices of the Royal Astronomical Society suggests its make-up is actually down to how the growing planet absorbed heavy and light materials as it formed and evolved.

Unlike what scientists once expected, the core of the largest planet in our solar system doesn’t have a sharp boundary but instead gradually blends into the surrounding layers of mostly hydrogen – a structure known as a dilute core.

How this dilute core formed has been a key question among scientists and astronomers ever since NASA’s Juno spacecraft first revealed its existence.

Using cutting-edge supercomputer simulations of planetary impacts, with a new method to improve the simulation’s treatment of mixing between materials, researchers from Durham University, in collaboration with scientists from NASA, SETI, and CENSSS, University of Oslo, tested whether a massive collision could have created Jupiter’s dilute core.

The simulations were run on the DiRAC COSMA supercomputer hosted at Durham University using the state-of-the-art SWIFT open-source software.

The study found that a stable dilute core structure was not produced in any of the simulations conducted, even in those involving impacts under extreme conditions.

Instead, the simulations demonstrate that the dense rock and ice core material displaced by an impact would quickly re-settle, leaving a distinct boundary with the outer layers of hydrogen and helium, rather than forming a smooth transition zone between the two regions.

Reflecting on the findings, lead author of the study Dr Thomas Sandnes, of Durham University, said: “It’s fascinating to explore how a giant planet like Jupiter would respond to one of the most violent events a growing planet can experience.

“We see in our simulations that this kind of impact literally shakes the planet to its core – just not in the right way to explain the interior of Jupiter that we see today.”

Jupiter isn’t the only planet with a dilute core, as scientists have recently found evidence that Saturn has one too.

Dr Luis Teodoro, of the University of Oslo, said: “The fact that Saturn also has a dilute core strengthens the idea that these structures are not the result of rare, extremely high-energy impacts but instead form gradually during the long process of planetary growth and evolution.”

The findings of this study could also help inform scientists’ understanding and interpretation of the many Jupiter- and Saturn-sized exoplanets that have been observed around distant stars. If dilute cores aren’t made by rare and extreme impacts, then perhaps most or all of these planets have comparably complex interiors.

Co-author of the study Dr Jacob Kegerreis said: “Giant impacts are a key part of many planets’ histories, but they can’t explain everything!

“This project also accelerated another step in our development of new ways to simulate these cataclysmic events in ever greater detail, helping us to continue narrowing down how the amazing diversity of worlds we see in the Solar System and beyond came to be.”

After wrapping up its investigation at the contact between clay and olivine-bearing rocks at “Westport,” Perseverance is journeying south once more. Previously, attempts were made to drive uphill to visit a new rock exposure called “Midtoya.” However, a combination of the steep slope and rubbly, rock-strewn soil made drive progress difficult, and after several attempts, the decision was made to return to smoother terrain. Thankfully, the effort wasn’t fruitless, as the rover was able to gather data on new spherule-rich rocks thought to have rolled downhill from “Midtoya,” including the witch hat or helmet-shaped rock “Horneflya,” which has attracted much online interest.

More recently, Perseverance explored a site called “Kerrlaguna” where the steep slopes give way to a field of megaripples: large windblown sand formations up to 1 meter (about 3 feet) tall. The science team chose to perform a mini-campaign to make a detailed study of these features. Why such interest? While often the rover’s attention is focused on studying processes in Mars’ distant past that are recorded in ancient rocks, we still have much to learn about the modern Martian environment.

Almost a decade ago, Perseverance’s forerunner Curiosity studied an active sand dune at “Namib Dune” on the floor of Gale crater, where it took a memorable selfie. However the smaller megaripples — and especially dusty, apparently no longer active ones like at “Kerrlaguna” — are also common across the surface of Mars. These older immobile features could teach us new insights about the role that wind and water play on the modern Martian surface.

After arriving near several of these inactive megaripples, Perseverance performed a series of measurements using its SuperCam, Mastcam-Z, and MEDA science instruments in order to characterize the surrounding environment, the size and chemistry of the sand grains, and any salty crusts that may have developed over time.

Besides furthering our understanding of the Martian environment, documenting these potential resources could help us prepare for the day when astronauts explore the Red Planet and need resources held within Martian soils to help them survive. It is hoped that this investigation at “Kerrlaguna” can provide a practice run for a more comprehensive campaign located at a more extensive field of larger bedforms at “Lac de Charmes,” further along the rover traverse.

Written by Melissa Rice, Professor of Planetary Science at Western Washington University

Jupiter core mystery not explained by giant planetary impact

by Sophie Jenkins

London, UK (SPX) Aug 22, 2025

A new Durham University study challenges the idea that Jupiter’s unusual dilute core was formed by a giant collision, overturning a leading explanation of the planet’s interior structure.

Jupiter’s core does not have a sharp boundary but gradually merges into its hydrogen-rich layers. This dilute core was first revealed by NASA’s Juno spacecraft, sparking debate about how it formed. Earlier research proposed that an ancient impact with another large planetary body could have mixed Jupiter’s center enough to produce this structure.

Researchers from Durham University, working with colleagues at NASA, SETI, CENSSS, and the University of Oslo, tested the hypothesis using high-resolution planetary impact simulations on the DiRAC COSMA supercomputer with the SWIFT open-source code. The models included improved methods for tracking how rock, ice, hydrogen, and helium mix during extreme impacts.

The results showed that even under extreme conditions, giant impacts did not yield a stable dilute core. Instead, displaced core materials re-settled quickly, maintaining a distinct separation from the outer hydrogen and helium layers.

The findings suggest that Jupiter’s dilute core arose not from a dramatic collision but from the way the planet accumulated heavy and light elements during its growth and evolution. Saturn has also been found to have a dilute core, reinforcing the idea that such structures form gradually rather than through rare, catastrophic impacts.

Lead author Dr Thomas Sandnes of Durham University said, “It’s fascinating to explore how a giant planet like Jupiter would respond to one of the most violent events a growing planet can experience. We see in our simulations that this kind of impact literally shakes the planet to its core – just not in the right way to explain the interior of Jupiter that we see today.”

Dr Luis Teodoro of the University of Oslo added, “The fact that Saturn also has a dilute core strengthens the idea that these structures are not the result of rare, extremely high-energy impacts but instead form gradually during the long process of planetary growth and evolution.”

The study also offers insights into the interiors of the many Jupiter- and Saturn-sized exoplanets now being discovered, suggesting that complex cores may be common among gas giants.

Co-author Dr Jacob Kegerreis concluded, “Giant impacts are a key part of many planets’ histories, but they can’t explain everything! This project also accelerated another step in our development of new ways to simulate these cataclysmic events in ever greater detail, helping us to continue narrowing down how the amazing diversity of worlds we see in the Solar System and beyond came to be.”

Research Report:No dilute core produced in simulations of giant impacts on to Jupiter

Related Links

Durham University

The million outer planets of a star called Sol

Following a successful launch of NASA’s SpaceX 33rd commercial resupply mission, new scientific experiments and cargo for the agency are bound for the International Space Station.

The SpaceX Dragon spacecraft, carrying more than 5,000 pounds of supplies to the orbiting laboratory, lifted off at 2:45 a.m. EDT on Sunday, on the company’s Falcon 9 rocket from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida.

“Commercial resupply missions to the International Space Station deliver science that helps prove technologies for Artemis lunar missions and beyond,” said acting NASA Administrator Sean Duffy. “This flight will test 3D printing metal parts and bioprinting tissue in microgravity – technology that could give astronauts tools and medical support on future Moon and Mars missions.”

Live coverage of the spacecraft’s arrival will begin at 6 a.m., Monday, Aug. 25, on NASA+, Netflix, Amazon Prime, and more. Learn how to watch NASA content through a variety of platforms, including social media.

The spacecraft is scheduled to dock autonomously at approximately 7:30 a.m. to the forward port of the space station’s Harmony module.

In addition to food, supplies, and equipment for the crew, Dragon will deliver several experiments, including bone-forming stem cells for studying bone loss prevention and materials, to 3D print medical implants that could advance treatments for nerve damage on Earth. Dragon also will deliver bioprinted liver tissue to study blood vessel development in microgravity, as well as supplies to 3D print metal cubes in space.

These are just a sample of the hundreds of biology and biotechnology, physical sciences, Earth and space science investigations conducted aboard the orbiting laboratory. This research benefits people on Earth while laying the groundwork for other agency deep space missions. As part of NASA’s Artemis campaign, the agency will send astronauts to the Moon to prepare for future human exploration of Mars, inspiring the world through discovery in a new Golden Age of innovation and exploration.

During the mission, Dragon also will perform a reboost demonstration of station to maintain its current altitude. The hardware, located in the trunk of Dragon, contains an independent propellant system separate from the spacecraft to fuel two Draco engines using existing hardware and propellant system design. The boost kit will help sustain the orbiting lab’s altitude starting in September with a series of burns planned periodically throughout the fall of 2025. During NASA’s SpaceX 31st commercial resupply services mission on Nov. 8, 2024, the Dragon spacecraft performed its first demonstration of these capabilities.

The Dragon spacecraft is scheduled to remain at the space station until December, when it will depart the orbiting laboratory and return to Earth with research and cargo, splashing down off the coast of California.

Learn more about the International Space Station at:

https://www.nasa.gov/international-space-station

-end-

Joshua Finch
Headquarters, Washington
202-358-1100
joshua.a.finch@nasa.gov

Steven Siceloff
Kennedy Space Center, Fla.
321-876-2468
steven.p.siceloff@nasa.gov

Sandra Jones / Joseph Zakrzewski
Johnson Space Center, Houston
281-483-5111
sandra.p.jones@nasa.gov / joseph.a.zakrzewski@nasa.gov

Topline

There’ s six-planet parade on Monday, Aug. 25, just before dawn. Saturn, Jupiter and bright Venus will dominate the scene, with Mercury putting in a fleeting appearance low in the east. Uranus and Neptune will be in the sky, but remain invisible without binoculars or a small telescope. However, time is short, with Mercury rapidly sinking into the suns’ glare by next week, reducing the parade to five.

Key Facts

Why It’s Not A ‘planetary Alignment’

You’ll hear the phrase “planetary alignment” to describe the view of the planets before sunrise this August. This is incorrect. The planets don’t wander randomly through space, only to align in an act if huge coincidence. Planets orbit the sun in nearly circular paths, all within the same flat plane. As seen from Earth, planets therefore appear in a line across the sky — the same line the sun takes through the sky — called the ecliptic. The moon also moves close to the ecliptic, occasionally crossing it when at new moon or full moon to cause an eclipse — hence its name. How many planets you can see at night depends on where Earth and other planets are in their orbits — not on any kind of chance alignment.

What’s Next In The ‘planet Parade’

After the spectacle of August’s planet parade, September brings a rich calendar of night-sky events. The month opens in style on Sept. 7 with a total lunar eclipse, visible across Asia, Africa, and western Australia, turning the full corn moon a pinkish, organgy color. On Sept. 19, Venus shines beside the star Regulus in Leo beneath a delicate crescent Moon. Two days later, a partial solar eclipse will sweep across the Pacific on the same date as Saturn reaches opposition, glowing at its brightest of 2025.

Further Reading

Forbes‘Planet Parade’ Myths Debunked And How To Truly See It — By A StargazerBy Jamie CarterForbesNASA Urges Public To Leave The City As Milky Way Appears — 15 Places To GoBy Jamie CarterForbes9 Places To Experience The Next Total Solar Eclipse A Year From TodayBy Jamie Carter

Researchers from Empa, Chinese Academy of Sciences, the Chinese University of Hong Kong and Max Planck Institute for Polymer Research have developed a hybrid system in which porphyrins are attached to graphene nanoribbons (GNRs) in a precise and well-defined manner. 

Image credit: Credit: Swiss Federal Laboratories for Materials Science and Technology

Graphene nanoribbons with zigzag edges are promising materials for spintronic devices, owing to their tunable bandgaps and spin-polarized edge states. Porphyrins offer complementary optoelectronic benefits. In the new system, a graphene ribbon just one nanometer wide with zigzag edges is used as a molecular wire, along which porphyrin molecules are docked at perfectly regular intervals, alternating between the ribbon’s left and right sides.

“Our graphene ribbon exhibits a special type of magnetism thanks to its zigzag edge,” explains Feifei Xiang, lead author of the study. The metal atoms in the porphyrin molecules, on the other hand, are magnetic in a more “conventional” way. The key difference lies in the electrons that provide the spin responsible for magnetism.

While the spin-carrying electrons in the metal center stay localized on the metal atom, the corresponding electrons in the graphene ribbon “spread out” along both edges.

“Thanks to the coupling of the porphyrins to the graphene backbone, we have succeeded in combining and connecting both types of magnetism in a single system,” explains co-author Oliver Gröning, deputy head of the nanotech@surfaces laboratory at Empa.

This coupling opens many doors in the field of molecular electronics. The graphene ribbon serves as both an electrical and magnetic conductor—a kind of nanoscale “cable” between the porphyrin molecules. The correlated magnetism of such graphene nanoribbons is considered particularly promising for quantum technology applications, where the spin underlying magnetism acts as an information carrier.

“Our graphene ribbon with the porphyrins could function as a series of interconnected qubits,” says Roman Fasel, head of the “nanotech@surfaces” laboratory.

In addition, porphyrins are also natural pigments, as seen in molecules like chlorophyll and hemoglobin. For materials scientists, this means that “the porphyrin centers are optically active,” says Gröning. And optics is an important way of interacting with the electronic and magnetic properties of such molecular chains. Porphyrins can emit light whose wavelength changes with the magnetic state of the entire molecular system—a kind of molecular string of lights, where information could be read out by subtle shifts in color.

The reverse process is also possible: The porphyrins could be excited by light, thereby influencing the conductivity and magnetism of the graphene backbone. These molecular all-rounders could even serve as chemical sensors.

Porphyrin molecules can be easily functionalized—that is, chemically modified by attaching specific chemical groups. If one of these added groups binds to a target chemical substance, this interaction also affects the conductivity of the graphene ribbon.

“Our system is a toolbox that can be used to tune different properties,” says Fasel. Next, the researchers plan to explore different metal centers inside the porphyrins and investigate their effects. They also aim to broaden the graphene ribbon backbone, giving their molecular system an even more versatile electronic base.

The synthesis of these “string lights” is anything but trivial. “Our partners at the Max Planck Institute were able to produce precursor molecules consisting of a porphyrin core complemented by a few carbon rings placed at exactly the right positions,” says Gröning.

These complex molecules are then “baked” at several hundred degrees Celsius under ultra-high vacuum to form the long chains. A gold surface serves as the “baking sheet.” This is the only way to achieve these nanometer-fine structures with atomic precision. The team is now working to make these novel designer materials usable for future quantum technologies.