Author: admin

The James Webb Space Telescope (JWST) is celebrating three years of transformational science with a striking new image of the Cat’s Paw Nebula — a vast nursery of stars located about 4,000 light-years from Earth in the constellation Scorpius.

Released Thursday (July 10), the JWST’s new image offers a dazzling close-up of a section of the nebula known for its distinctive, pawprint-like appearance thanks to large, circular structures that resemble a feline’s “toe beans,” the soft pads on the bottom of cats’ paws.

Protoplanetary disks made of gas and dust form around young stars, and this is where planets from. These disks don’t last forever. Eventually, the star’s energetic output dissipates the disk through photoevaporation, the material gets taken up in planets, and the planet-forming process ceases.

All young stars are expected to have protoplanetary disks, and these dusty environments make it difficult to see young planets forming. Astronomers recently observed a binary star with separate disks. The primary star has cleared out its dusty protoplanetary disk, while its companion hasn’t. Now that the primary star has cleared away the obscuring dust, it’s an excellent target for direct imaging of planets.

The research is titled “Direct imaging discovery of a young giant planet orbiting on Solar System scales,” and it’s published in Astronomy and Astrophysics. The lead author is Tomas Stolker. He’s an assistant professor of astronomer at the Leiden Observatory at Leiden University in the Netherlands.

The double star system is called HD 135344 AB and it’s about 440 light-years away from Earth. A and B are both young stars, and they orbit each other widely, indicating that their protoplanetary disks evolved separately. The primary star is an A-type main-sequence star, and the secondary star is an F-type main-sequence star.

The critical aspect of this binary system is that the primary star has cleared away its protoplanetary disk, while the secondary star hasn’t. The secondary star has been studied for decades, largely because it’s still forming planets. Observations revealed a central cavity in the disk, spiral arms, and variable shadowing, all features that suggest planet-disk interactions, even though any actual planets are shielded from observations by thick dust.

The primary star, on the other hand, appears to have no disk, and hasn’t attracted much attention. However, that lack of dust makes it a prominent location to search for exoplanets. In the new research, the team used the Very Large Telescope (VLT) and its SPHERE exoplanet instrument to directly image a planet orbiting the primary star, HD 135344 A. It took four years of dedicated observations with powerful instruments to detect it.

“Star A had never been investigated because it does not contain a disk. My colleagues and I were curious about whether it had already formed a planet,” said Stolker in a press release. “And so, after four years of careful measurements and some luck, the answer is yes.”

This figure shows detections of HD 135344 Ab with the VLT and its SPHERE instrument. Four of the images are from it IRDIS (Infra-Red Dual Imaging and Spectrograph) instrument, and two are from its IFS (Integral Field Spectrograph) instrument. The planet is seen in westward direction (i.e., toward the right). The color scale is linear and normalized to the brightest pixel in each image. Image Credit: VLT/SPHERE; Stolker et al. 2025. A&A

HD 135344 Ab is a young planet with about 10 Jupiter masses. It orbits at 15-20 astronomical units from its star, and its spectral type is mid-L, meaning it bridges the gap between a brown dwarf or a gas giant. It’s no more than 12 million years old, making it one of the youngest directly-imaged planets.

The fact the primary star has ceased forming planets while the secondary star is still forming planets shows that binary stars can have different planet-formation and protoplanetary disk lifetimes.

When they first detected the planet, it was unclear if it was a planet or a star. But the VLT is a powerful and flexible telescope. It’s made of four separate yet identical scopes that can be used as an interferometer, and four smaller auxiliary scopes that can be positioned independently. This allowed the VLT and SPHERE to map the planet’s location with extreme accuracy. Over time, they saw the star and the suspected planet move together, confirming that it’s a planet.

This figure from the research shows how the astronomers determined that the new planet was not another star. It shows that the planet moves mostly eastward, whereas the background sources move northeast. The crosses show the positions of HD 135344 Ab, which moves eastward. The colored circles show the positions of the suspected background sources in the IRDIS field of view, which are connected with dotted lines between epochs. The dashed line shows the track for a stationary background source. Image Credit: Stolker et al. 2025. A&A

“We’ve been lucky, though,” says Stolker. “The angle between the planet and the star is now so small that SPHERE can barely detect the planet.”

Observing and imaging exoplanets is an extremely difficult tasks. Most exoplanet discoveries are inferred from observational data and presented with artist’s illustrations which are interpretations of the data. Though the images of HD 135344 Ab don’t show any planetary detail, they are direct images rather than representations.

The researchers say that the planet likely formed near its solar system’s snow line. Scientists think that this is a key region for giant planet formation. Different materials are available there because volatiles like water, ammonia, and methane are solids there rather than gases. The collective boost to available solid surfaces means it’s easier for dust grains to stick together and eventually grow into planets.

It was challenging to determine that the planet was not a background star, something that hinders the direct imaging of exoplanets. Gaia astrometric data plays a big role in this. “This study also highlights the importance of high-precision astrometric measurements to fully disentangle orbital from background motion in a region of non-stationary background stars,” the authors explain.

But it also took some lucky timing. “A good portion of luck was involved with the discovery of HD 135344 Ab, however, because we caught the planet at a favorable separation along its inclined orbit,” the authors write in their conclusion. “In the next 10 to 20 years, the angular separation with its star will decrease to ≈10–35 mas, which means that the planet would not have been discovered with SPHERE for a large fraction of its orbit.”

Direct imaging surveys show that giant planets like this one are rare at wider separations of 20 au or greater. The detection of these planets at shorter separations is expected to increase when the ESA’s Gaia astrometric mission releases its fourth dataset in 2026. That data will guide the quest to directly image more exoplanets. “Gaia DR4 may reveal hints of similar close-in giant planets in star-forming regions, which will guide direct imaging searches and post-processing algorithms,” the researchers explain.

“HD 135344 Ab might be part of a population of giant planets that could have formed in the vicinity of the snowline,” the authors write. ‘These objects have remained challenging to detect since most surveys and observing strategies have not been optimized for such small separations.”

If there is a population of young giant planets like this one, exoplanet scientists would love to find them. They could learn a great deal about giant planet formation from them. When they do detect them, the next step is to study them in greater detail. The upcoming Extremely Large Telescope, set to see first light in 2029, will have the power to do this. This will reveal more about these planets, their compositions, and how they form.

Earth started out as a ball of liquid fire, its newborn surface closer to a lava lamp than the calm continents we know today. Those incandescent beginnings happened 4.5 billion years ago, yet the evidence is buried miles beneath our feet where direct sampling is impossible.

A new computer model of the infant planet’s mantle says the rock we stand on still remembers that fiery youth, right down to the chemical fingerprints laid down within the planet’s first hundred million years.

Assistant Professor Charles‑Édouard Boukaré, Department of Physics and Astronomy, York University, led the new study.

Early Earth was a molten world

When the young Earth cooled, it did not freeze evenly like a lake in winter. It simmered from the top down and the bottom up at the same time, leaving pockets of melt trapped deep inside.

Planetary scientists call that global melt a basal magma ocean, a deep layer of iron‑rich liquid pooling just above the metal core, and its existence explains why the modern core still loses heat so slowly.

Seismic scans of the modern deep mantle reveal sprawling ultralow velocity zones that slow earthquake waves, hinting they contain that same dense, iron‑heavy melt and supporting the basal ocean concept.

These reservoirs sit beneath the Pacific and Africa today, covering areas wider than the continental United States, yet they are hard to image because they lie nearly eighteen hundred miles down.

Exactly when those structures formed has been uncertain because many earlier simulations treated the mantle as a single gooey fluid, erasing the complex dance between liquid and crystal that governs segregation.

Modeling magma to solid rock

The code named Bambari by the researchers divided Earth’s interior into a fine grid and began with a half‑melted mantle, about fifty percent liquid, a state thought to be realistic after the giant impact that created the Moon.

Temperature contrasts made lighter crystal mush rise while heavier, iron‑loaded droplets sank, all as heat bled into cold space, and the model resolved motions at scales from global overturns to turbulent eddies only a few miles across.

Within a few thousand simulated years the top hundred miles had cooled enough for crystals to lock together, forming down‑plunging sheets that ferried a shallow chemical signal into the deep, a result that surprised the research team.

More crystals formed near the surface than near the core, overturning the textbook view that solidification begins at depth, and the outcome hints that early Earth might have sported a short‑lived rocky crust that repeatedly sank back into the mantle.

Because the falling crystals reheated and partly melted on the way down, they left behind an iron‑rich brew that eventually puddled into an ocean of liquid rock roughly three hundred miles thick above the core, one that may have persisted for half a billion years and acted as a blanket trapping core heat.

Surprising chemistry on early Earth

Low‑pressure minerals such as olivine were expected to dominate only the upper mantle, yet Boukaré’s run shows their fingerprints nearly twelve‑hundred miles below.

This finding that forces a rethink of how trace elements were sorted. The reason is mechanical: surface‑grown crystals fell like hailstones, skipping equilibrium reactions at depth.

As they sank, mass balance pumped iron‑rich melt upward where it chilled, creating downwellings enriched in trace elements such as samarium and neodymium, and the pattern repeated until the mantle became mostly solid.

That process stamped unusual Lu/Hf and Sm/Nd ratios that still appear in 3.8 billion‑year‑old rocks from Greenland, offering a rare chemical time capsule of early differentiation.

“This study is the first to demonstrate that the first‑order features of Earth’s lower mantle structure were established four billion years ago,” said Boukaré.

Remnants in Earth’s mantle today

The simulation naturally birthed the two giant “superplumes,” formally known as large low shear‑velocity provinces or LLSVPs, that sit under the Pacific and Africa and rise more than six‑hundred miles off the core.

In the model they form as the dregs of the magma ocean, loaded with iron and slightly radioactive elements that keep them hotter than their surroundings, an explanation that unifies decades of seismic and geochemical hints.

That extra heat helps feed volcanic hotspots such as Hawaii and Iceland, linking events separated by billions of years through persistent mantle circulation.

High‑precision noble‑gas measurements in ocean‑island basalts point to ancient, undegassed mantle domains that match the predicted reservoirs, giving independent support to the model’s deep‑time narrative.

Because the model reproduces both seismic and chemical observations, it knits together disciplines that rarely intersect and offers a single story for the planet’s deep past.

What this means for other planets

The equations behind Bambari apply to any rocky world, big or small, making the tool valuable far beyond Earth studies.

For Mars, whose lower mass bleeds heat faster, the basal magma ocean would have frozen early, starving the core of insulation and hastening the loss of its magnetic shield within a few hundred million years, a scenario that dovetails with rover data showing weak residual magnetism in surface rocks.

For a super‑Earth twice our planet’s size, the same physics predicts a magma ocean that could linger a billion years, sustaining a long‑lived dynamo and perhaps protecting an atmosphere long enough for life to emerge.

“If we know some kind of starting conditions, and we know the main processes of planetary evolution, we can predict how planets will evolve,” Boukaré explained. That prospect gives exoplanet hunters a fresh tool for judging habitability without leaving the telescope.

The study is published in Nature.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–