Ganymede’s Aurora Patch: Discovering Similarities with Earth’s Aurora Physics

Scientists from the United States, Europe, and China utilized the Ultraviolet Spectrometer (UVS) on NASA’s Juno spacecraft to meticulously map the auroral patch structure on Ganymede, Jupiter’s moon, revealing similarities to Earth’s auroras. Their groundbreaking research indicates that interactions between magnetic fields and charged particles could be the universal driver of auroras, enhancing our understanding of magnetospheres across the solar system.

Artist’s concept of the aurora borealis on Jupiter’s moon Ganymede. Image credits: NASA/ESA/G. Bacon, STScI/J. Saur, University of Cologne.

Ganymede stands out as the only known moon to possess its intrinsic magnetic field, creating a miniature magnetosphere nested within the vast magnetosphere of Jupiter.

The auroral emissions primarily stem from oxygen at wavelengths of 130.4 nm and 135.6 nm, triggered by precipitating electrons.

In a recent groundbreaking study, researcher Philippe Gusbin from the University of Liège and his team examined ultraviolet observations of Ganymede conducted on June 7, 2021, by the Juno spacecraft.

They identified multiple auroral spots in Ganymede’s leading downstream hemisphere.

These patches typically measure about 50 km in size, with brightness levels soaring to around 200 Rayleigh.

“Auroras on Ganymede are driven by the precipitation of electrons into its thin oxygen atmosphere,” explained Gusbin.

“Previous observations of Ganymede’s auroras were limited in detail due to the spatial constraints of ground-based methods, which couldn’t resolve the fine structures commonly observed in planetary auroras.”

The morphology and scale of Ganymede’s auroras closely resemble the auroral ‘beads’ found on Earth prior to magnetospheric substorms and in Jupiter during ‘dawn storms.’

The lack of a similar patch in the southern hemisphere could stem from observational geometry, but it may also reflect an asymmetry tied to Ganymede’s location in Jupiter’s plasma disk.

“Auroral ‘beads’ are also present in the auroras of Earth and Jupiter, where they correlate with substorms and dawn storms—major magnetospheric reorganizations that release significant energy and induce intense auroral activity,” noted Dr. Alessandro Moirano, a postdoctoral researcher at the University of Liège and the National Institute of Astrophysics in Rome.

This discovery implies that similar physical processes may govern magnetospheres, despite variations in scale and environmental conditions.

“Juno’s close flyby of Ganymede lasted under 15 minutes, and it will not revisit Ganymede, leaving us unsure about the frequency of these patches or how they may evolve,” remarked Dr. Bertrand Bonfont, an astrophysicist at the University of Liège.

“Fortunately, ESA’s JUICE mission is currently en route to Jupiter and is set to arrive in 2031. This mission will conduct detailed observations of Ganymede.”

“Equipped with a similar ultraviolet spectrometer to that of Juno, this spacecraft will facilitate long-term observations that could reveal more about the evolution of Ganymede’s aurora and potentially uncover new mysteries.”

For further reading, refer to a paper published in Astronomy and Astrophysics.

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A. Moirano et al. 2026. High spatial resolution ultraviolet observations of Ganymede’s aurora patches by Juno. Constraints on the magnetospheric source region. A&A 706, L16; doi: 10.1051/0004-6361/202558379

Source: www.sci.news

Humpback Whale Songs Show Similarities to Human Language Patterns

Humpback whales in the South Pacific

Tony Woo/Nature Picture Library/Aramie

Humpback whale songs have statistical patterns in their structure, but they are very similar to those found in human language. This does not mean that songs convey complex meanings like our sentences, but that whales may learn songs in a similar way to how human infants begin to understand language. It suggests.

Only male humpback whales (Megaptera novaeangliae) When you sing, actions are considered important to attract peers. The songs are constantly evolving, and new elements appear and spread in the population until old songs are replaced with completely new ones.

“I think it's like a standardized test. Everyone has to do the same task, but changing or decorating to show that they're better at tasks than others can be done. You can do it.” Jenny Allen At Griffith University, in the Gold Coast, Australia.

Instead of trying to find meaning in songs, Allen and her colleagues were looking for innate structural patterns similar to those found in human language. They analyzed eight years of whale songs recorded around New Caledonia in the Pacific Ocean.

The researchers began by creating alphanumeric codes to represent all the songs on every recording, including a total of around 150 unique sounds. “Essentially it's a different sounding group, so maybe a year will make a groaning cry. So we may have an AAB.

Once all the songs were encoded, a team of linguists had to understand how best to analyze so much of the data. The breakthrough occurred when researchers decided to use an analytical technique that applies to methods of discovering words called transition probability.

“The speech is continuous and there is no pause between words, so infants must discover the boundaries of the word.” Invalanon At Hebrew University in Jerusalem. “To do this, use low-level statistics. Specifically, if they are part of the same word, the sounds are more likely to occur together. Infants Use these dips in the possibility of discovering the boundaries of words following another sound.”

For example, the phrase “cute flower” intuitively recognizes that the syllable “pre” and “tty” are more likely to go together than “tty” or “flow.” “If there is a similar statistical structure in a whale song, these cues should also help segment it,” Arnon says.

Using the alphanumeric version of Whale Song, the team calculated the probability of transition between successive sound elements and cut it when the previous sound elements were amazing.

“These cuts divide the song into segmented subsequences,” Arnon says. “We then looked at their distribution and, surprisingly, discovered that they follow the same distribution as seen in all human languages.”

In this pattern called Zipfian distribution, the prevalence of less common words drops in a predictable way. Another impressive finding is that the most common whale sounds tend to be shorter, as is the case with the most common human language.

Nick Enfield At the University of Sydney, who was not involved in the research, it says it is a novel way to analyze whale songs. “What that means is when you analyze it War and peacethe most frequent words are the next twice as often, and researchers have identified similar patterns in whale songs,” he says.

Team Members Simon Carby The University of Edinburgh in the UK says he didn't think this would work. “I will never forget the moment the graph appears. It appears to be familiar from human language,” he says. “This has made me realize that it uncovered a deep commonality between these two species, separated by tens of millions of years of evolution.”

However, researchers emphasize that this statistical pattern does not lead to the conclusion that whale songs are languages ​​that convey meaning as we understand them. They suggest that the possible reason for commonality is that both whale songs and human languages ​​are culturally learned.

“The physical distribution of words and sounds in languages ​​is a truly fascinating feature, but there are millions of other things about languages ​​that are completely different from whale songs,” Enfield says.

In another study It was released this week, Mason Young Blood At Stony Brook University in New York, we found that other marine mammals may also have structural similarities to human language in communication.

Menzeras' law predicting that sentences with more words should consist of shorter words were present in 11 of the 16 species of disease studied. The ZIPF abbreviation law was discovered in two of the five types in which the available data can now be detected.

“To sum up, our research suggests that humpback whale songs have evolved to be more efficient and easier to learn, and that these features can be found in the level of notes within the phrase, phrases within the song. I'm doing it,” Youngblood says.

“Importantly, the evolution of these songs is also biological and cultural. Although some features, such as Menzerath's Law, can emerge through the biological evolution of voice devices, Other features such as the rank frequency method of ZIPF are [the Zipfian distribution]there may be times when cultural communication of songs between individuals is necessary,” he says.

topic:

  • animal/
  • Whale and dolphin

Source: www.newscientist.com

What similarities do ancient Egyptians and octopuses share?

Historically, the brain was not always recognized as the center of thought. In ancient Egypt, it was believed that the heart held intellect and the soul, resulting in the preservation of the heart in mummified bodies, while the brain was discarded.

In the 5th century B.C., Greek scholar Alcmaion of Croton made claims about the brain, but two centuries later, Aristotle still upheld the belief that the heart was the seat of intelligence.

Octopuses are an interesting example, as about two-thirds of their neurons are found in their tentacles, allowing for semi-independent responses to stimuli. This challenges the idea of a central location for thought.

Advancements in AI models, like ChatGPT, show that conscious thought can be produced without physical sense organs, resembling human thought processes.

While modern neuroscience confirms that the brain controls perception, thinking, and language, cultural and religious beliefs can shape ideas about consciousness and its origins.

In various indigenous cultures, consciousness is often associated with spirits or ancestors, separate from the physical body. Sensations like hunger and pain also demonstrate that thought is not solely contained in the brain.

If our brains and stomachs were reversed, we might view conscious thought as originating in the stomach, with the head serving as a sensory and input location.

This article explores the question of whether we would “think from our stomachs” if our brains were located there, reflecting on the nature of consciousness.

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New Study Finds Surprising Similarities in Brain Development Between Sea Lampreys and Humans

The lamprey and human hindbrains are built using very similar molecular and genetic toolkits, according to a new study led by the Stowers Institute for Medical Research.



These images show an adult lamprey (top and left) and a developing lamprey embryo. Image credit: Stowers Medical Research Institute.

“Our research on the hindbrain (the part of the brain that controls important functions such as blood pressure and heart rate) is essentially a window into the distant past and can serve as a model for understanding the evolution of complexity. “, said Dr. Hugo Parker. Researcher at Stowers Medical Research Institute.

Like other vertebrates, sea lampreys have a backbone and skeleton, but they noticeably lack a jaw, a characteristic feature of the head.

Most vertebrates, including humans, have jaws, so this striking difference in sea lampreys makes it a valuable model for understanding the evolution of vertebrate traits.

“About 500 million years ago, at the origin of vertebrates, there was a split between jawless and jawed animals,” said Dr. Alice Bedois, also of the Stowers Institute for Medical Research.

“We wanted to know how vertebrate brains evolved and whether there is something unique to jawed vertebrates that jawless vertebrates don't.”

Previous research had identified genes that structure and subdivide the sea lamprey's hindbrain as identical to genes in jawed vertebrates, including humans.

However, these genes are part of an interconnected network or circuit that needs to be initiated and directed to properly build the hindbrain.

In a new study, the authors identify common molecular cues known to direct head-to-tail patterning in a variety of animals as part of a genetic circuit that guides hindbrain patterning in the lamprey. .

“We found that the same genes, as well as the same cues, are involved in hindbrain development in sea lampreys. This suggests that this process is ancestral to all vertebrates. ,” Dr. Bedwa said.

“This signal is called retinoic acid, commonly known as vitamin A.”

Researchers have known that retinoic acid signals the genetic circuits that build the hindbrains of complex species, but they believe it is involved in more primitive animals like sea lampreys. was not considered.

Surprisingly, they discovered that the lamprey's core hindbrain circuit is also initiated by retinoic acid, providing evidence that these sea monsters and humans are much more closely related than expected.

“People thought that because lampreys don't have jaws, their hindbrains don't form like other vertebrates,” says Dr. Rob Krumlauf, a researcher at the Stowers Institute for Medical Research.

“We showed that this fundamental part of the brain is built exactly the same way as in mice, and even in humans.”

Signaling molecules that signal cell fate during development are well known.

Now, researchers have discovered that retinoic acid plays another key role in signaling important steps in development, such as the formation of the brainstem.

Furthermore, if hindbrain formation is a conserved feature in all vertebrates, other mechanisms must be involved to explain its incredible diversity.

“We all come from a common ancestor,” Dr. Bedwa said.

“The lamprey provided further clues.”

“We now need to go further back in evolutionary time to discover when the genetic circuits controlling hindbrain formation first evolved.”

of study It was published in the magazine nature communications.

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AMH Bedwa other. 2024. Lamprey reveals the origins of retinoic acid signaling and its coupling to vertebrate hindbrain segments. Nat Commune 15, 1538. doi: 10.1038/s41467-024-45911-x

Source: www.sci.news