Recently I am getting more emails from various countries—all of whose senders wish to be anonymous—about indigenous people trying to combine their own “ways of knowing” with science or to represent them as an alternative to modern science (often mistakenly called “Western” science). The anonymity, of course, comes because criticism of indigenous people is about the worst blasphemy you can commit against “progressive” liberals, who regard indigenous people as historically and currently oppressed by “settlers”.
In this case, though, the indigenous knowledge isn’t purely indigenous, but an effort to piggyback on or to ape modern science. The article below, from the Royal Society of Chemistry News, involves Australians and Aboriginals together trying to develop an indigenous periodic table.
When you ask “a periodic table of what?”, it appears to be a periodic table of the elements. But the elements were identified by modern science, and of course placed in the modern periodic table by the work of non-indigenous chemists and physicists. The proposed indigenous table, however, uses the very same elements, but wants to classify them in a different way: by how they are used, how they are connected to the land, and so on. This would also change the names of the elements.
Also, as the article points out, there are over 400 indigenous groups in Australia, each with a different language and presumbly a different culture, so we’d get dozens of periodic tables. If that’s the outcome, then what is the point of this exercise?
Click on the headline below to read the short article:
The craziness of this endeavor, which seems to have no point save to give indigenous people something resembles what the “Western” settler-colonialist scientists have, can best be seen in a few quotes. “I have a dream today”, says one professor, who is not aboriginal but apparently an “ally”:
‘I have a dream of walking into a chemistry lecture theatre and seeing two periodic tables – the traditional one and a periodic table in the language of the Gadigal whose land we teach on,’ says Anthony Masters, a chemistry professor at the University of Sydney in Australia. The Gadigal are one of over 400 different Aboriginal communities in Australia and the Torres Straight Islands that have their own distinct set of languages, histories and traditions. Masters has pulled together a team of Aboriginal and non-Aboriginal scholars to investigate what an Indigenous periodic table might look like. Together, the multidisciplinary team aims to organise the elements in a format that represents the relationships between them based on Indigenous knowledge.
Masters, apparently not even a member of the Gadigal, seemingly wants to do this as a scientific sop to the aboriginals “whose land we teach on.” But if that’s the case, I’m sure the Gadigal would much prefer to be paid for the appropriated land, or given their land back.
So what is this table? Well, perhaps it doesn’t seem to involve elements, but compounds or minerals:
In reality, Aboriginal people developed their own knowledge of the chemical elements and their compounds. This includes uranium in its mineral form, which they called sickness rocks because they were aware that mishandling them could cause illness. Moreover, Aboriginal Australians have been using the iron oxide-based pigment ochre for at least 50,000 years. Historically, it had economic value, being traded between different tribes, but it also remains central to several cultural practices including body painting and decorating sacred objects. ‘Ochre is used as a pigment, and it can be formed into different colours – which is material science. It can be used as a disinfectant, as a sunscreen. A lot of these things are to do with its interaction with light,’ explains Masters who uses these examples to teach his undergraduate students about attributing knowledge to the Indigenous community.
But uranium doesn’t occur free in nature (often it’s found as “uraninite“, also known as “pitchblende”, UO2 but with other minerals), and ochre, according to Wikipedia, is “is a natural clay earth pigment, a mixture of ferric oxide and varying amounts of clay and sand.” (One of the few elements that can be seen occurring in its pure form in nature is sulfur.) Are we to have a periodic table of compounds, then? If so, that will be a very large periodic table! The problem of distinguishing elements from compunds isn’t even mentioned, but it appears that they want to do this for elements (see below).
The article then says that the traditional and correct periodic table of the elements is largely useless to an indigenous person:
The idea to develop an Indigenous periodic table arose because Masters started looking into how language influences our understanding of chemical knowledge and how chemistry is taught at Australian universities. ‘How do you know that oxygen and sulfur have similar properties? You can’t tell from the names,’ says Masters. Regarding palladium, he points out there is little to no value in an Indigenous student learning about an element named after an asteroid, which in turn was named after a Greek goddess. And what about neon, which William Ramsay named after the Greek word for new, but it’s hardly new after 120 years. Instead, Masters wants Indigenous Australian students to grow up with a periodic table in their language, just as it exists in other languages around the world.
But you don’t discern chemical properties from the names but from the position in the scientific periodic table. And who cares what the element is called? Scientists or anybody who wants to learn chemistry, that’s who. But Masters & Co. want to change the names of the elements/compounds. If you make a periodic table in this way, if you even can, it will not help indigenous people learn modern chemistry; it will in fact impede them.
But it appears that this project is grinding exceedingly slowly, and I doubt it will happen at all, especially because it’s limited to just one group of aboriginals. The slowness may result from their need to construct the table by talking. Bolding below is mine:
Troy explains the team’s first step was to ask the Sydney Mob – which encompasses over 29 Indigenous communities based in the Sydney region – if an Australian First Nationsperiodic table was something they would be interested in. They were. And so began the delicate process of establishing what scientific understanding of the elements is inherent in Aboriginal Australian knowledge systems.
Being mindful of and engaging with Aboriginal culture is central to the project, and face-to-face consultations are the preferred medium of meeting in Indigenous communities. So, the team has started the process of yarning – an Indigenous practice of sharing knowledge through conversations – with elders from the Gadigal clan. ‘The idea of yarning is that you give people a chance to talk and then you consider what they talk about. And then you respectfully engage with what they’ve been talking about,’ explains Troy. This means the project is developing slowly as yarning can take a very long time, with no expectations or pressure on the Indigenous people to immediately embrace the project. They are still planning yarning workshops (at the time of publishing) to continue engagement with as many of the community as they can.
. . . There is no timeline for when the team might complete its first Indigenous periodic table, but the team has begun developing a methodology to move the project forward. Part of that includes creating a blueprint that other Aboriginal groups can adapt and use themselves to document the elements and the relationships between them. With over 400 languages in Australia, each element may have a different meaning. ‘It’s in that spirit that the Periodic table is an obvious example. There are different ways of looking at things. And for me, that’s one of the beauties of [chemistry],’ concludes Masters.
. . . The meetings and conversations, which have already been under way for two years, have confirmed the project is worthwhile.
Really? How so?
Finally, it becomes clear that the goal is indeed to make an indigenous periodic table of elements, not compounds. And the purpose is given below as well: an indigenous periodic table (which does not now exist) is needed because a simple indigenous representation of the scientific periodic table might “erase Indigenous knowledge”:
So far, the team notes that the Gadigal spoken to in initial meetings like how the traditional periodic table combines nomenclature from Latin and Greek, as well as Arabic and Anglo-Saxon, but this is subject to change as more community members are consulted. ‘Some of the elements are named after people. Some are named after their qualities. But it is quite inconsistent,’ says Troy. They are therefore looking for a consistent style in the Gadigal language that might work and considering the relationship between the elements in the understanding of local knowledge holders. One idea is to group together elements that are part of daily life, elements that hold a special place in ceremony and elements that are avoided.
. . . It’s important to understand that the team doesn’t intend for an Indigenous periodic table to be a direct translation of the traditional periodic table because that could end up erasing rather than celebrating Indigenous knowledge. And it might not necessarily look like a table. Rather they’re aiming to represent the elements in a chart that also reflects Indigenous understanding concerning how an element connects to the lands, water and skies on which the First Nations people live. ‘We have to translate the concept culturally,’ says Tory, using a First Nations approach. Strategies the team is investigating include, but are not limited to, using Indigenous language to express a unique characteristic of an element or using Indigenous language to express the etymology of the English term. However, the most important factor is that the choice is made by the Indigenous community to suit their cultural and ideological foundations.
So they are apparently going to take the elements known from modern chemistry, many of which are not encountered by indigenous peoples in a pure state (hydrogen, neon, etc.) and group them together in ways that are supposed to be useful to the local people. But since they don’t know the pure elements, how can they do this? I cannot see how.
More important, why are they doing this? It appears to me to be a performative act to ape modern science but in a far less useful way: “See, we can order the elements according to our own culture.” That is fine if they want to try, but that ordering, even if it were possible, will not be useful in teaching chemistry to aboriginal people. The periodic table is useful because it tells you something about the atomic structure of an element, which in turn tells you something about how it behaves chemically. What other kind of ordering makes sense?
Finally, given that indigenous people from various parts of Australia, and of the world, encounter different compounds that are used or recognized differently, even if one could make an indigenous periodic table of elements (which seems to me impossible), there would be dozens or hundreds of them, each representing the concepts of a different culture. There will not be a “correct” periodic table and so, in the end, we will have many orderings that represent sociology or anthropology and not science.
And that means that Anthony Masters’s dream is only a pipe dream, and his Indigenous Periodic Table does not belong in a chemistry lecture theater.
h/t: Ginger K.
The idea of Dyson Sphere’s has been around for decades. When Freeman Dyson explored the concept he acknowledged that they may not be a physical sphere but could be a swarm of satellites in a spherical configuration around a star. The challenge with a solid sphere is that its orbit will not be stable leading to its destruction. A new paper casts a new view on that though and proposes a way that a rigid sphere could be stable after all. The idea suggests that a binary star system, where the mass ratio between the two objects is small, the sphere may be stable.
The Dyson Sphere is a theoretical megastructure that was first proposed by physicist Freeman Dyson in 1960 as a method to harness the energy output of a star. The concept may take the form of a massive shell or a swarm, or network of solar-collecting satellites circling a star to capture and utilise its energy, potentially providing virtually limitless power. Dyson acknowledged that the construction of a solid sphere around a star is impractical due to immense material and stability challenges, a more feasible design involves a Dyson swarm—a collection of orbiting solar power stations.
Freeman Dyson speak at the Long Now Foundation.The idea of a solid sphere has taken a back seat over recent years and indeed studies have focussed on searches for satellite swarms. The acceptance that such a solid structure is not stable has been supported by other studies. In 1856, James Clark Maxwell showed that Saturn’s rings too, could not possibly be a solid uniform structure. The interaction of gravity between the ring and the planet would result in instability. The same was thought to be true for a Dyson Sphere. That was until Colin R McInnes published his findings in the monthly notices of the Royal Astronomical Society.
Saturn and its system of rings, acquired by the Cassini probe. Credit: NASA/JPL-CaltechMcInnes argues that a solution lies within the circular restricted three-body problem. This is a classical problem from celestial mechanics. At its core, it describes the motion of a small body (such as an asteroid) under the gravitational influence of two larger objects (like the Sun and Jupiter) which are in circular orbits around their common centre of mass. The presence of the smaller object, which has negligible mass has no significant impact on the motion of the two larger bodies.
In such a system, there would be five equilibrium points known as Lagrange points. Two of these will be unstable but two of them (L4 and L5) will be stable but only if the mass ratio is small as in Jupiter and the Sun for example. Here, an object will remain in a stable orbit. There are extensions and more complicated models to consider where for example radiation pressure has an impact on the stability of a system.
McInnes finds that there are configurations that could be stable for a sphere or ring after all but only under specific conditions. The first occurs if the two primary masses in the system are in orbit around their common centre of mass and a large uniform ring encloses the smaller mass. Of perhaps more interest is that McInnes suggests even a sphere could be stable if it encloses the smaller of the two masses.
The results of the study reveal an enticing glimpse into a universe where Dyson sphere’s may not be just restrained to science fiction. That there may be stellar systems scattered across the cosmos where advanced civilisations have harnessed the energy from one of their local stars.
Source : Ringworlds and Dyson spheres can be stable
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As Lysenkoism 2.0 looms, those of us who have warning about this for years are not to blame for the problems we write about, and we have nothing to apologize for.
The post I Confess My Sins: I Was Too Slow and Timid to Call Out Propaganda For What It Is. first appeared on Science-Based Medicine.Roughly 4.6 billion years ago, the Sun was born from the gas and dust of a nebula that underwent gravitational collapse. The remaining gas and dust settled into a protoplanetary disk that slowly accreted to form the planets, including Earth. About 4.5 billion years ago, our planet was impacted by a Mars-sized body (Theia), which led to the formation of the Moon. According to current theories, water was introduced to Earth and the inner planets by asteroids and comets that permeated the early Solar System.
The timing of this event is of major importance since the introduction of water was key to the origin of life on Earth. Exactly when this event occurred has been a mystery for some time, but astronomers generally thought it had arrived early during Earth’s formation. According to a recent study by a team led by scientists from the University of Rutgers-New Brunswick, water may have arrived near “late accretion” – the final stages of Earth’s formation. These findings could seriously affect our understanding of when life first emerged on Earth.
The team was led by Katherine Bermingham, an associate professor in the Department of Earth and Planetary Sciences at Rutgers-New Brunswick and the University of Maryland. She was joined by researchers from Clemson University, the Research Centre for Astronomy and Earth Sciences (CSsFK), the Department of Lithospheric Research, the Centre for Planetary Habitability (PHAB), and the Institute for Earth Sciences. Their findings are described in a paper, “The non-carbonaceous nature of Earth’s late-stage accretion,” in Geochimica et Cosmochimica Acta.
Artist’s impression of the giant impact that shaped the Earth and created the Moon.According to what scientists have learned from life on Earth, three ingredients are essential to putting the process in motion. These are water, energy, and the basic building blocks of organic chemicals – carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur – collectively called CHNOPS. As a cosmogeochemist, Bermingham and her associates are dedicated to the study of the chemical composition of matter in the Solar System. This largely consists of analyzing Earth rocks and materials deposited by meteorites and other extraterrestrial sources.
In so doing, they hope to learn more about the origin and evolution of the Solar System and its rocky planets. A major aspect of this is knowing when and where the basic ingredients for life originated and how they found their way to Earth. For their study, Birmingham and her team examined meteorites obtained from the Smithsonian National Museum of Natural History that belong to the “NC” group. These meteorites’ composition suggests they formed in the inner Solar System, where conditions were drier.
This sets them apart from the “CC” group, which likely formed in the outer Solar System, where water and other volatiles were more abundant. The team extracted isotopes of molybdenum from these meteorites – a trace mineral essential for human health – and analyzed them using ionization spectrometry and a new analytical method they developed. This element is thought to have been deposited on Earth at about the same time the Moon formed, which was thought to have deposited a significant amount of the Earth’s water. As Birmingham explained in a Rutgers University press release:
“When water was delivered to the planet is a major unanswered question in planetary science. If we know the answer, we can better constrain when and how life developed. The molybdenum isotopic composition of Earth rocks provides us with a special window into events occurring around the time of Earth’s final core formation, when the last 10% to 20% of material was being assembled by the planet. This period is thought to coincide with the Moon’s formation.”
A piece of iron meteorite Campo del Cielo, one of the samples measured in the study. Credit: Katherine BerminghamThey then compared the composition of these meteors’ isotopes to Earth rocks obtained by field geologists from Greenland, South Africa, Canada, the United States, and Japan. Their analysis showed that the Earth rocks were more similar to meteorites originating in the inner Solar System (NC). As Birmingham said:
“Once we gathered the different samples and measured their isotopic. compositions, we compared the meteorites signatures with the rock signatures to see if there was a similarity or a difference. And from there, we drew inferences. We have to figure out from where in our solar system Earth’s building blocks – the dust and the gas – came and around when that happened. That’s the information needed to understand when the stage was set for life to begin.”
The finding is significant since it indicates that Earth did not receive as much water from the Moon-forming impact as previously theorized. Instead, the data supports the competing school of thought that water was delivered to Earth in smaller portions late in its formation history and after the Moon was formed. “Our results suggest that the Moon-forming event was not a major supplier of water, unlike what has been thought previously,” said Bermingham. “These findings, however, permit a small amount of water to be added after final core formation, during what is called late accretion.”
Further Reading: Rutgers University, Geochimica et Cosmochimica Acta
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The James Webb Space Telescope (JWST) has been giving us a fabulous new view on the universe since its launch. This new image of the protostar HH30 is in amazing new detail thanks to the JWST. It was first discovered using the Hubble Space Telescope but this Herbig-Haro object, which is a dark molecular cloud, is a perfect object for JWST. The image shows the protoplanetary disk seen edge on with a conical outflow of gas and dust with a narrow jet blasting out into space.
The JWST is arguably the most advanced space observatory ever built. It was launched on December 25, 2021 and orbits the Sun at the second Lagrange point, about 1.5 million kilometres from Earth. It has a 6.5-meter gold-coated mirror and powerful infrared instruments which can peer through dust to study the formation of stars, galaxies, and even exoplanet atmospheres. It has already given us amazing images of deep space to reveal galaxies from the early universe.
Artist impression of the James Webb Space TelescopeRecently JWST has been used to study the protostar HH30. It’s a young star system located about 450 light-years away in the constellation Taurus and is embedded in the dark cloud LDN1551. At its centre lies a newborn star embedded in a dense disk of gas and dust, which fuels its formation.
HH30 is a Herbig-Haro object, a small, bright nebulae which has been found in a star-forming region. The nebula is created when high-speed jets of ionized gas from the newborn stars collide with surrounding interstellar material. They are typically located near protostars and are often aligned along the axis of bipolar outflows. As the jets travel through space at hundreds of kilometers per second, they create shock waves that heat the surrounding gas, causing it to glow in visible and infrared wavelengths. Herbig-Haro objects tend to be transient, evolving over a few thousand years as the jets interact with changing environments.
The system is best known for its spectacular bipolar jets, which shoot out from the protostar at high speeds. Observations from the Hubble Space Telescope have revealed a stunning silhouette of the dusty disk, seen edge-on, obscuring the central star while allowing astronomers to study the complex processes of star and planet formation.
The team of astronomers combined images from JWST, HST and the Atacama Large Millimetre Array (ALMA) so that they could study the appearance of the disk in multiple wavelengths. The observations have been wonderfully captured in this new image that has been released as Picture of the Month. HH30 is seen in unprecedented detail.
This image of NASA’s Hubble Space Telescope was taken on May 19, 2009 after deployment during Servicing Mission 4. NASAJWST is known for its infrared capabilities and allowed the team to track the location of sub-millimetre sized grains of dust but ALMA allowed the team to explore further. Using ALMA millimetre-sized grains of dust were studied revealing that they, unlike the smaller dust grains, were found in a narrow region in the plane of the disc. The smaller grains were found to be much more widespread.
The study concluded that larger grains of dust seem to migrate within the disc and settle into a thin layer. It’s thought this marks an important part of the formation of planetary systems with the grains clumping together to form smaller rocks and ultimately into planets.
Not only did the study reveal the behaviour of grains of dust in HH30 but it also uncovered a number of different structures embedded within one another. A narrow, high-velocity jet was seen to be emerging from the central disc. The jet seems to be surrounded by a wider, rather more cone shaped outward flow of gas. Not only does this study help us to learn more about how exoplanetary systems form but it helps us to understand more about the origins of our own Solar System.
Source : Webb investigates a dusty and dynamic disc
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Hypervelocity stars (HVSs) were first theorized to exist in the late 1980s. In 2005, the first discoveries were confirmed. HVSs travel much faster than normal stars, and sometimes, they can exceed the galactic escape velocity. Astronomers estimate that the Milky Way contains about 1,000 HVSs, and new research shows that some of these originate in the Milky Way’s satellite galaxy, the Large Magellanic Cloud (LMC).
Does the LMC have a supermassive black hole (SMBH) that’s ejecting some HVSs into the Milky Way?
Most stars in the Milky Way travel at about 100 km/s, whereas HVSs can travel as quickly as about 1000 km/s. Established thinking, backed up by existing evidence, says that HVSs originate in the Galactic Centre. Astronomers think they come from binary star systems that get too close to Sgr. A*, the Milky Way’s SMBH. In this scenario, one of the binary stars is captured by the black hole, and the other is ejected as an HVS. This is called the Hills mechanism. In fact, some of the original evidence supporting the existence of Sgr. A* was based on fast-moving stars in the galactic center by the Hills mechanism.
New research submitted to The Astrophysical Journal shows that a surprising number of the Milky Way’s HVSs come not from the galactic centre but from the LMC. It’s titled “Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud.” The lead author is Jiwon Han, a grad student at the Harvard and Smithsonian Center for Astrophysics who studies galactic archaeology.
In 2006, researchers published the results of a survey of HVSs in the Milky Way. That survey detected 21 HVSs that were unbound B-type main sequence stars in the Milky Way’s outer halo. Their properties were consistent with stars ejected from the galactic center by the Hills mechanism. In this new research, the astronomers revisited these stars. They had some help that wasn’t available in 2006: the ESA’s Gaia spacecraft.
Gaia is our star-measuring superhero. It sits at the Sun-Earth L2 point, where it measures two billion objects, mostly stars, and tracks their positions and velocities. Han and his colleagues revisited the 21 HVSs using the proper motions provided by Gaia. Gaia, a mission that has driven substantial progress in our understanding of the Milky Way, came through again.
“We find that half of the unbound HVSs discovered by the HVS Survey trace back not to the Galactic Center, but to the LMC,” Han and his co-authors write.
That motivated them to dig deeper. The researchers constructed a model based on simulated stars that were ejected by an SMBH in the LMC. “The predicted spatial and kinematic distributions of simulated HVSs are remarkably similar to the observed distributions,” the authors write.
This pie chart shows the results of the team’s analysis of the HVSs. “Among the HVSs that can be confidently classified, 9 out of 16 stars originate from the LMC center,” the authors explain. Image Credit: Han et al. 2025.speeds
Could there be another root cause of the HSVs? Supernova explosions can eject stars, and so can dynamic gravitational interactions. Those can’t explain them, according to the authors. “We find that the birth rate and clustering of LMC HVSs cannot be explained by supernova runaways or dynamical ejection scenarios not involving an SMBH,” the authors explain.
One key piece of evidence supporting a black hole in the LMC is an overdensity. Called the Leo overdensity, it’s a region toward the Leo constellation that contains a higher density of stars than the surrounding regions. Han and his co-researchers say their model also produces this same overdensity. An SMBH with about 600,000 solar masses in the LMC is hurling stars into the Milky Way, some of which are HVSs, some of which are now residing in the overdensity.
The researcher’s model predicts the existing overdensity of stars in the Milky Way toward the Leo constellation, called the Leo overdensity. “The black open circles denote the Galactic coordinates of hypervelocity stars detected in the HVS Survey, while the grey-shaded regions mark areas excluded from the survey,” the authors explain. “This model accurately reproduces the observed overdensity location, supporting the hypothesis of an SMBH in the LMC as a source of these stars.” Image Credit: Han et al. 2025.Their model shows that almost all of the stars in the Leo overdensity came from the LMC and its SMBH, which the authors describe as “a curious result.” To understand it better, they dug into how the Hills mechanism works.
“The main ingredients of the Hills Mechanism are: (1) the mass of LMC, (2) binary star masses, (3) binary
separations prior to tidal disruption, (4) pericenter distances of the binary orbit around the SMBH,” the authors write. These are inputs into the Hills mechanism, and the outputs are ejection probabilities and velocities for individual stars.
For ejected stars, the researchers integrated their orbits forward for 400 million years to see where they would go. “We finally ‘observe’ the resulting population of stars from the Galactic rest frame at the present day and apply a selection function to match the observational constraints of the HVS Survey,” the authors write.
This figure illustrates some of the modelling and the results. (1) shows the LMC rest-frame velocities of stars ejected from the LMC by the SMBH. (2) shows the velocity of these stars in the rest-frame of the Milky Way. “The size of each point is proportional to the excess velocity over the local Galactic escape velocity,” the authors write. (3) shows stars that exceed the galactic escape velocity, which reveals a stream of hypervelocity stars ahead of the LMC’s orbit. (4) shows the stars that made it into the HVS Survey. Basically, the leading tip of hypervelocity stars from the LMC is the LEO overdensity. Image Credit: Han et al. 2025.
The implications of this research could be far-reaching. Current thinking says that all large galaxies contain an SMBH but that smaller galaxies don’t. There’s some evidence that smaller galaxies can harbour them, but in dwarf galaxies like the LMC, for example, the black holes may not be massive enough to qualify as actual SMBHs, depending on where the cut-off is. Additionally, they’re more difficult to detect in dwarf galaxies because they may not be actively accreting matter.
This research changes things.
It shows that the presence of a black hole does not generate HVSs alone; the motion of the galaxy also contributes. Future studies of HVSs need to consider galactic motion.
The study also has ramifications for our understanding of galaxy growth and evolution. If astrophysicists are missing black holes in smaller galaxies, that means our theories of galactic evolution are likely lacking consequential data.
More research into HVSs will take these results into account. Gaia data may help find more HVSs when more becomes available in future data releases. That means more data points, something scientists are always looking for. With that data, researchers can build more detailed models and develop more stringent theories on HVSs and how they’re generated.
Research: Hypervelocity Stars Trace a Supermassive Black Hole in the Large Magellanic Cloud
The post There Could Be a Supermassive Black Hole in the Large Magellanic Cloud Hurling Stars at the Milky Way appeared first on Universe Today.
We’ve only gotten one close-up view of Uranus and its moons, and it happened decades ago. In 1986, Voyager 2 performed a flyby of Uranus from about 81,500 km (50,600 mi) of the planet’s cloud tops. It was 130,000 km (80,000 mi) away from Uranus’ moon, Ariel, when it captured the leading image. It showed some unusual features that scientists are still puzzling over.
What do they reveal about the moon’s interior?
Ariel has the usual crater-pitted surface that most Solar System objects display. But its surface also has complex features like ridges, canyons, and steep banks and slopes called scarps. Research published last year suggested that these surface features and chemical deposits are caused by chemical processes inside the moon. Ariel could even have an internal ocean, according to the research.
New research published in The Planetary Science Journal digs deeper into the issue to try and understand what processes could create Ariel’s surface features. Its title is “Ariel’s Medial Grooves: Spreading Centers on a Candidate Ocean World.” The lead author is Chloe Beddingfield from Johns Hopkins University Applied Physics Laboratory (JHUAPL).
“Ariel is a candidate ocean world, and recent observations from the James Webb Space Telescope (JWST) confirmed that its surface is mantled by a large amount of CO2 ice mixed with lower amounts of CO ice,” Beddingfield and her co-researchers write in their paper. These materials should be unstable on Ariel, though, and should sublimate away into space. “Consequently, the observed constituents on Ariel are likely replenished, possibly from endogenic sources,” the authors write.
The research is centred on Ariel’s chasma-medial groove systems and how they formed. These are trenches that cut straight through the moon’s huge canyons. While previous research has suggested that the trenches are tectonic fractures, this research arrives at a different hypothesis. “We present evidence that Ariel’s massive chasma-medial groove systems formed via spreading, where internally sourced material ascended and formed new crust,” the paper states.
This Voyager 2 image of Ariel shows the names of some of the moon’s surface features. Image Credit: By Ariel_(moon).jpg: NASA/Jet Propulsion Labderivative work: Ruslik (talk) – Ariel_(moon).jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12867133This is similar to ocean-floor spreading on Earth, which is where new crust forms. If true, it can account for Ariel’s surface deposits of carbon dioxide ice and other carbon-bearing molecules.
“If we’re right, these medial grooves are probably the best candidates for sourcing those carbon oxide deposits and uncovering more details about the moon’s interior,” Beddingfield said in a press release. “No other surface features show evidence of facilitating the movement of materials from inside Ariel, making this finding particularly exciting.”
Ariel’s surface is dominated by three main terrain types: plains, ridged terrain, and cratered terrain. The cratered terrain is the oldest and most extensive type of terrain. The ridged terrain is the second main terrain type and is made of bands of ridges and troughs that can extend for hundreds of kilometres. The plains are the third type and are the youngest of the terrains. They’re on canyon floors and in depressions in the middle of the cratered terrain.
As far as scientists can tell, the grooves that intersect the canyons are the youngest surface features on Ariel. Previous research suggested that they result from the interplay between volcanic and tectonic processes. However, this research says otherwise: spreading could be responsible.
This image (Figure 1) from the research puts Ariel’s complex surface on full display. The locations of the three known medial grooves are shown in red. Image Credit: Beddingfield et al. 2025.In the 1960s, scientists validated the idea of seafloor spreading on Earth, which led to the acceptance of plate tectonics. One of the main pieces of evidence for plate tectonics is the way the edges of continents like Africa and South America fit together if you “remove” the Atlantic Ocean and the intervening seafloor.
The same thing happened when Beddingfield and her colleagues “removed” the chasm floors on Ariel.
The researchers showed that when they removed the floors of the chasms, the margins lined up. This is strong evidence of spreading. “The margins of Brownie, Kewpie, Korrigan, Pixie, and Sylph Chasmata closely align when the Intermediate Age Smooth Materials (orange unit in Figure 1), which make up the chasma floors, are removed and the Cratered Plains (green unit in Figure 1) are reconstructed,” they write.
This figure from the study shows possible configurations of Ariel’s Cratered Plains before (left) and after (right) spreading occurred. Note how neatly the chasma walls line up. “Our reconstruction focuses on removing the young chasma floors, examining the offset of the Kra Chasma segments, and aligning the similarly shaped chasma walls,” the authors write. Image Credit: Beddingfield et al. 2025.According to the research, spreading centers develop above convention cells underneath Ariel’s crust, and heat forces material upward to the crust. The material cools at the surface, forming new crust. The entire process is driven by tidal forces as Ariel orbits the much larger Uranus. This heats the moon’s interior, creating the convection. Some of the moon’s interior cycles between heating as the moon follows its orbit. It’s possible that internal material continuously melts and then refreezes.
“It’s a fascinating situation — how this cycle affects these moons, their evolution and their characteristics,” Beddingfield said.
Like other Solar System moons that experience tidal heating, Ariel may have an ocean under its surface. In a 2024 study, researchers proposed that another of Uranus’ moons, Miranda, could have a subsurface ocean maintained by tidal heating.
However, Beddingfield is skeptical about drawing a connection between Ariel’s grooves and a potential ocean.
“The size of Ariel’s possible ocean and its depth beneath the surface can only be estimated, but it may be too isolated to interact with spreading centers,” she said. “There’s just a lot we don’t know. And while carbon oxide ices are present on Ariel’s surface, it’s still unclear whether they’re associated with the grooves because Voyager 2 didn’t have instruments that could map the distribution of ices.”
The connection between the grooves and the materials deposited on Ariel’s surface is stronger though. “These new results suggest a possible mechanism for emplacing fresh material and short-lived compounds, including carbon monoxide and perhaps ammonia-bearing species on the surface,” said Tom Nordheim, a co-author of this research and the 2024 paper.
“Our results indicate that medial grooves in large chasmata on Ariel are spreading centers, resulting from the exposure of subsurface material, creating new crust,” the authors summarize in their conclusion. “Thus, these features are likely geologic conduits to Ariel’s interior and could be the primary source of CO2, CO, and other volatiles detected on its surface.”
Richard Cartwright from the Johns Hopkins Applied Physics Laboratory led the 2024 study that used the JWST to identify CO ice and CO2 deposits on Ariel. To find more answers about this intriguing moon, Cartwright says we need a dedicated mission to Uranus and its moons. “We need an orbiter that can make close passes of Ariel, map its medial grooves in detail, and analyze their spectral signatures for components like carbon dioxide and carbon monoxide,” he said. “If carbon-bearing molecules are concentrated along these grooves, then it would strongly support the idea that they’re windows into Ariel’s interior.”
The authors agree that only a dedicated mission can provide answers. “The medial grooves are some of the youngest geologic features observed on Ariel, and close flybys of these features by a future Uranus orbiter are imperative to gain insight into recent geologic events and the geologic and geochemical properties of this candidate ocean world,” they write.
There’ve been many proposed missions to Uranus. NASA, the ESA, JAXA, and the CNSA (China National Space Administration) have all had proposals. NASA’s Uranus Orbiter and Probe mission would study Uranus and its moons from orbit by conducting multiple flybys of each major moon. The probe would enter Uranus’ atmosphere. However, even if selected, a plutonium shortage means the mission wouldn’t launch until the mid or late 2030s.
A graphic explaining some of the features of NASA’s proposed Uranus Orbiter and Probe mission. Image Credit: NASA.So far, only China has firm plans to send a spacecraft to the ice giant. It will be part of their Tianwen-4 mission to Jupiter and would perform a single flyby of Uranus. The next launch windows for a mission to Uranus are between 2030 and 2034, but China’s mission isn’t scheduled until 2045.
Press Release: New Study Suggests Trench-Like Features on Uranus’ Moon Ariel May Be Windows to Its Interior
Research: Ariel’s Medial Grooves: Spreading Centers on a Candidate Ocean World
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