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Saturn regains status as planet with most moons in solar system

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Saturn has regained its crown as the planet with the most moons in the solar system, just months after being overtaken by its fellow gas giant Jupiter.

The leap-frog comes after the discovery of 62 new moons of Saturn, bringing its official total to 145. Jupiter, which added 12 moons to its tally in February, has 95 moons that have been formally designated by the International Astronomical Union (IAU).

“Saturn not only has nearly doubled its number of moons, it now has more moons than all the rest of the planets in the solar system combined,” said Prof Brett Gladman, an astronomer at the University of British Columbia who was involved in the observations.

The new moons, which have been assigned strings of numbers and letters for now, will eventually be given names based on Gallic, Norse and Canadian Inuit gods, in keeping with convention for Saturn’s moons. Gladman said his team would be consulting with Inuit elders to ask for proposals that could be put to the IAU for approval.

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Many of the new objects are likely to be remnants of a relatively recent moon-moon collision that resulted in a larger moon fracturing and “spreading its children” in orbit about the planet.

While it is possible that Jupiter may, in future, temporarily inch ahead, the latest findings appear to cement the case that, ultimately, Saturn has more moons. Since Jupiter is closer, astronomers can spot much smaller moons.

“At a fixed size there are three times more Saturn satellites than Jupiter satellites,” said Gladman. “They’re not all known yet, but we already know the final answer.”

In recent decades, the number of confirmed moons has steadily increased as telescopes and analysis methods have stepped up in sensitivity. The latest study used a technique called “shift and stack” to discover fainter, and smaller, satellites. It involves shifting sequential images at the rate that the moon is moving across the sky, making the moon appear brighter when all the data is combined.

Dr Edward Ashton, who led the project at the University of British Columbia and now works at Taiwan’s Academia Sinica Institute of Astronomy and Astrophysics, compared the challenge of connecting the various appearances of the moons in the data to a child’s dot-to-dot drawing. “But with about 100 different games on the same page and you don’t know which dot belongs to which puzzle,” he said.

The team used data taken using the Canada-France-Hawaii Telescope on top of Mauna Kea, Hawaii between 2019 and 2021, to detect moons down to a diameter of 2.5km.

It is hoped that Nasa’s Dragonfly mission, due to launch in 2027, will be able to make closer observations of at least one of Saturn’s small outer moons.

Separately, scientists have published findings suggesting that the rings of Saturn were acquired relatively recently in the history of the solar system. Experts working on data collected by Nasa’s Cassini spacecraft said the latest observations suggest that the massive rings did not form at the same time as the planet, but formed no more than 400m years ago.

“It is natural to think that the rings have been formed together with Saturn [which is] about 4.5bn years old,” said Dr Sascha Kempf, a co-author of the research at the University of Colorado Boulder.

But it seems that Saturn’s rings are not here to stay: research has previously revealed they are disintegrating.

“The rings are not for eternity and we are probably lucky that we can observe them now,” Kempf said.

 

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Heat transport in energy materials: Study clarifies fundamental microscopic mechanisms – Phys.org

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Temporary formation of a defect pair in copper iodide. Although these defects only survive for a couple of picoseconds, i.e., for a trillionth of a second, they substantially influence macroscopic heat transport processes. Credit: Florian Knoop, NOMAD Laboratory

The NOMAD Laboratory researchers have recently shed light on fundamental microscopic mechanisms that can help with tailoring materials for heat insulation. This development advances the ongoing efforts to enhance energy efficiency and sustainability.

The role of heat transport is crucial in various scientific and , such as catalysis, turbine technologies, and thermoelectric heat converters that convert into electricity.

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Particularly in the context of energy conservation and the development of sustainable technologies, materials with high thermal insulation capabilities are of utmost importance. These materials make it possible to retain and utilize heat that would otherwise go to waste. Therefore, improving the design of highly insulating materials is a key research objective in enabling more energy-efficient applications.

However, designing strongly heat insulators is far from trivial, despite the fact that the underlying fundamental physical laws have been known for nearly a century. At a , heat transport in semiconductors and insulators was understood in terms of the collective oscillation of the atoms around their equilibrium positions in the crystal lattice. These oscillations, called “phonons” in the field, involve a huge number of atoms in and hence cover large, almost macroscopic length- and time-scales.

In a recent joined publication in Physical Review B and Physical Review Letters, researchers from the NOMAD Laboratory at the Fritz Haber Institute have advanced the computational possibilities to compute thermal conductivities without experimental input at unprecedented accuracy. They demonstrated that for strong heat insulators the above-mentioned phonon picture is not appropriate.

Using large-scale calculations on supercomputers at of the Max Planck Society, the North-German Supercomputing Alliance, and the Jülich Supercomputing Centre, they scanned over 465 crystalline materials, for which the thermal conductivity had not been measured yet. Besides finding 28 strong thermal insulators, six of which feature an ultra-low thermal conductivity comparable to wood, this study shed light on a hitherto typically overseen mechanism that allows one to systematically lower the thermal conductivity.

“We observed the temporary formation of defect structures that massively influences the atomic motion for an extremely short period of time,” says Dr. Florian Knoop (now Linköping University), first author of both publications.

“Such effects are typically neglected in simulations, since these defects are so short-lived and so microscopically localized compared to typical heat-transport scales, that they are assumed to be irrelevant. However, the performed calculations showed that they trigger lower thermal conductivities,” adds Dr. Christian Carbogno, a senior author of the studies.

These insights may offer new opportunities to fine-tune and design thermal insulators on a nanoscale level through defect engineering, potentially contributing to advances in energy-efficient technology.

More information:
Florian Knoop et al, Anharmonicity in Thermal Insulators: An Analysis from First Principles, Physical Review Letters (2023). DOI: 10.1103/PhysRevLett.130.236301

Florian Knoop et al, Ab initio Green-Kubo simulations of heat transport in solids: Method and implementation, Physical Review B (2023). DOI: 10.1103/PhysRevB.107.224304

Citation:
Heat transport in energy materials: Study clarifies fundamental microscopic mechanisms (2023, June 9)
retrieved 10 June 2023
from https://phys.org/news/2023-06-energy-materials-fundamental-microscopic-mechanisms.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

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A "supervolcano" in Italy last erupted in 1538. Experts warn it's "nearly to the breaking point" again. – CBS News

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A long-dormant “supervolcano” in southern Italy is inching closer to a possible eruption — nearly six centuries after it last erupted, according to European researchers. 

The Campi Flegrei volcano, which is located near the city of Naples, has become weaker over time and as a result is more prone to rupturing, according to a peer-reviewed study conducted by researchers from England’s University College London and Italy’s National Research Institute for Geophysics and Volcanology. 

The study used a model of volcano fracturing to interpret the patterns of earthquakes and ground uplift. There have been tens of thousands of earthquakes around the volcano, and the town of Pozzuoli, which rests on top of Campi Flegrei, has been lifted by about 13 feet as a result of them. The quakes and rising earth have stretched parts of the volcano “nearly to the breaking point,” according to a news release about the study, and the ground seems to be breaking, rather than bending. 

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A view of the Pozzuoli city seafront and Campi Flegrei.

Salvatore Laporta/KONTROLAB/LightRocket via Getty Images


The earthquakes are caused by the movement of fluids beneath the surface, the news release said. It’s not clear what those fluids are, but researchers said they may be molten rock, magma or natural volcanic gas. 

The earthquakes have taken place during the volcano’s active periods. While it last erupted in 1538, it has been “restless” for decades, with spikes of unrest occurring in the 1950s, 1970s and 1980s. There has been “a slower phase of unrest” in the past 10 years, researchers said, but 600 earthquakes were recorded in April, setting a new monthly record. 

According to LiveScience, Campi Flegrei is often referred to as a “supervolcano,” which can produce eruptions reaching a category 8 — the highest level on the Volcano Explosivity Index. However, Campi Flegrei’s biggest-ever eruption technically ranked as a category 7, which is still considered a very large and disastrous eruption, LiveScience reported.   

While Campi Flegrei — which means “burning fields” — may be closer to rupture, there is no guarantee that this will actually result in an eruption, the study concluded. 

“The rupture may open a crack through the crust, but the magma still needs to be pushing up at the right location for an eruption to occur,” said Professor Christopher Kilburn, who studies earth sciences at University College London and was the lead author of the study. 

Solfatara di Pozzuoli, is one of the forty craters of Campi
Solfatara di Pozzuoli, one of the forty craters of Campi Flegrei.

Vincenzo Izzo/LightRocket via Getty Images


Kilburn said that this is the first time the model has been applied to a volcano in real-time. Since first using the model in 2017, the volcano has behaved as predicted, Kilburn said, so researchers plan to expand the use of the model to look at other volcanoes that reawakened after long periods of dormancy. The goal is to establish more reliable criteria to decide if an eruption is likely and establish a model that can be applied to multiple volcanoes. 

“The study is the first of its kind to forecast rupture at an active volcano. It marks a step change in our goal to improve forecasts of eruptions worldwide,” Kilburn said.

Satellite view of Campi Flegrei
Satellite image of Campi Flegrei also known as the Phlegrean Fields, a supervolcano located mostly under the Gulf of Pozzuoli west of Naples on December 09, 2016 in Campi Flegrei, Italy.

/ Getty Images


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Mountains 3 To 4 Times Higher Than Mount Everest Found Deep Inside Earth: Scientists – NDTV

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These underground mountain peaks are called ultra-low velocity zones or ULVZs.

The deep Earth contains mountains with peaks three to four times higher than Mount Everest, scientists have found. According to the BBC, a team of experts from Arizona State University used seismology centres in Antarctica and found these astonishingly huge mountains in the boundary between the core and mantle, around 2,900 kilometres deep inside our planet. 

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“The mountain-like structures they revealed are utterly mysterious,” the BBC report read. Scientists explained that these underground mountain ranges – dubbed ultra-low velocity zones or ULVZs – had managed to escape the experts’ gaze all these years until earthquakes and atomic explosions generated enough seismic data to be spotted by them. 

Scientists believe that these huge mountain ranges are over 24 miles (38 kilometres) in height, while Mount Everest is around 5.5 miles (8.8 kilometres) from the surface. “Analysing 1000’s of seismic recordings from Antarctica, our high-definition imaging method found thin anomalous zones of material at the CMB [core-mantle boundary] everywhere we probed,” Arizona State University geophysicist Edward Garnero said in a statement.

“The material’s thickness varies from a few kilometres to 10’s of kilometres. This suggests we are seeing mountains on the core, in some places up to 5 times taller than Mt. Everest,” he added. 

Also Read | Stephen Hawking’s Famous Theory Could Mean That Entire Universe Is Doomed To Evaporate: Study

Further, as per the report, experts explained the possible reason behind the formation of these mysterious mountain peaks. They believe that these ancient formations were created when oceanic crusts were formed into Earth’s interior. They also argue that it might have begun with tectonic plates slipping down into our planet’s mantle and sinking to the core-mantle boundary. These then slowly spread out to form an assortment of structures, leaving a trail of both mountains and blobs. This would, therefore, mean that these mysterious mountains are made of ancient oceanic crust, which is a combination of basalt rock and sediments from the ocean floor. 

Now, with this recent discovery, scientists are seeking to argue that these underground mountains may play a critical role in how heat escapes the Earth’s core. “Seismic investigations, such as ours, provide the highest resolution imaging of the interior structure of our planet, and we are finding that this structure is vastly more complicated than once thought,” study co-author and University of Alabama geoscientist Samantha Hansen said in a statement.  

“Our research provides important connections between shallow and deep Earth structure and the overall processes driving our planet,” she added. 

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