Tag Archives: Donut

Saturn’s Rings Create a Massive Dusty Donut Encircling the Planet

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A stunning view of Saturn and its rings as seen by the Cassini spacecraft

NASA/JPL-Caltech/Space Science Institute

New findings indicate that dust particles from Saturn’s rings are extended farther above and below the planet than previously assumed, implying that the rings might be shaped like large, dusty donuts.

The central structure of Saturn’s rings is remarkably thin, stretching out for tens of thousands of kilometers while only measuring around 10 meters in height, which gives Saturn its iconic look from Earth. However, variations exist, such as the outer E-ring that is inflated and replenished by ice ejected from Saturn’s moon Enceladus, which has an ocean beneath its surface.

In a recent study, Frank Postberg and his team at the Free University of Berlin examined data from NASA’s Cassini spacecraft, which completed 20 orbits in its final year of operation in 2017. During these orbits, the spacecraft took a steep trajectory through the rings, starting from a distance up to three times Saturn’s radius and moving downwards towards three times Saturn’s radius.

At the height of Cassini’s orbital path, its spectrometer, known as the Cosmic Dust Analyzer, detected hundreds of tiny rock particles with a chemical makeup similar to those found in the iron-deficient main rings. “This spectral type is genuinely unique within the Saturn system,” Postberg stated.

“While more material is near the surface of the rings, it is still astonishing that these particles are found so far above and below the ring surface,” he added.

Postberg and his collaborators determined that to reach heights greater than 100,000 kilometers from the main ring, the particles must be traveling at speeds exceeding 25 kilometers per second to break free from Saturn’s gravitational and magnetic forces.

Postberg noted that the exact mechanism achieving such speeds remains uncertain. The simplest explanation might be that a minor meteorite strikes the ring, scattering particles; however, this does not generate debris quickly enough.

New research suggests that when micrometeorites impact Saturn’s rings, they could generate sufficiently high temperatures to vaporize the rocks, implying that Saturn’s rings are older than once believed. Postberg and his team propose that this vaporized rock could exit the ring at much higher speeds than expected and then condense far from the planet.

It is surprising to find dust at such distances from the main ring. According to Frank Spahn from the University of Potsdam in Germany, who was not part of the study, this is significant because the particles in Saturn’s primary rings are small, collide rarely, and are sticky, leading to collisions that behave more like snowballs colliding than like billiard balls.

Micrometeorite impacts are prevalent throughout the solar system; hence, similar processes might be occurring on other ringed planets like Uranus. “If a ring of ice experiences a high-velocity impact, this phenomenon could be widespread; we would expect analogous dust rings above and below the other rings,” Postberg concluded.

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Source: www.newscientist.com

Detailed Image of Black Hole Unveiled in New Fiery Donut Visualization

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The image on the right is the latest and best image of a black hole.

EHT collaboration

Thanks to an update to the world’s first black hole image taken a year later, we now have the most detailed observation of a black hole to date.

In 2019, researchers released an image of the supermassive black hole known as M87*, located 55 million light-years away at the center of galaxy M87. The image, the world’s first glimpse of a black hole, was taken during the first observations in 2017 by a network of radio astronomical observatories around the world called the Event Horizon Telescope (EHT).

Now, the EHT collaboration has released tracking images of M87* taken during 2018 observations using additional telescopes in Greenland.

As the name suggests, these objects do not emit light, so the light in the image does not come out of the black hole. What we see instead is the silhouette of a black hole at the center of a mass of hot material, pulled inward by its powerful gravity.

“This image tells us that the black hole’s shadow is permanent and still exists,” says the EHT scientist. Eduardo Ross. “You can see that the ring is a beautiful circle. It’s very circular, not an oval or anything. We also see an enhancement on the south side in this ring, which is what we expected.”

This enhancement, visible as a slightly bright glow under the slightly displaced shadow of M87*, is due to the distortion of space-time associated with the black hole’s rotation (as explained by Albert Einstein’s theory of general relativity). This is due to

The additional telescopes have slightly increased the resolution of the images, greatly increasing the amount of data that can be cross-referenced with observations from other telescopes. However, less than ideal weather made viewing conditions difficult. This means the resolution is not as high as theoretically expected, Ross says.

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Source: www.newscientist.com

Unraveling Subtle Mysteries with “Donut” Rays

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Researchers at the University of Boulder have advanced the field of ptychography by innovating a new imaging method using donut-shaped light beams. This technique enables detailed imaging of small regularly patterned structures such as semiconductors, overcoming previous limitations of conventional microscopy. This advance promises significant improvements in nanoelectronics and biological imaging. (Artist’s concept) Credit: SciTechDaily.com

In a new study, researchers at the University of Boulder used a donut-shaped beam of light to take detailed images of objects too small to be seen with traditional microscopes.

Advances in Nanoelectronic Imaging

This new technology could help scientists improve the inner workings of a variety of ‘nanoelectronics’, including miniature ones. The semiconductor inside a computer chip. This discovery was featured in a special issue on December 1st. Optics and Photonics News called Optics in 2023.

Ptychography: A Lens into the Microscopic World

This research is the latest advance in the field of ptychography, a challenging yet powerful technique for seeing very small things. Unlike traditional microscopes, ptychography tools do not directly observe small objects. Instead, it shines a laser at a target and measures how the light is scattered. This is a bit like making shadow puppets on a wall when viewed through a microscope.

A scattering pattern produced by donut-shaped rays of light reflecting off an object with a regularly repeating structure. Credit: Wang et al., 2023, optica

Overcoming Ptychography Challenges

So far, the approach has worked surprisingly well, with one major exception, said Margaret Mahne, the study’s lead author and distinguished professor of physics.

“Until recently, we had been completely unsuccessful with highly periodic samples or objects with regularly repeating patterns,” says the UW-Boulder and National Institute of Standards and Technology (NIST) collaboration. Margaret, a fellow at JILA, said, “That’s a problem because this has a lot of nanoelectronics in it.”

She pointed out that many important technologies, such as some semiconductors, are made up of atoms such as silicon and carbon bonded in regular patterns, like small grids or meshes. So far, it has proven difficult for scientists to observe these structures up close using ptychography.

Donut-shaped beams of light scatter from incredibly small structures. Credit: Wang et al., 2023, optica

A Breakthrough in Donut-Shaped Light

But in a new study, Murunet and colleagues have come up with a solution. Instead of using a traditional laser in a microscope, they generated a donut-shaped beam of extreme ultraviolet light.

The researchers’ new approach can collect precise images of small, delicate structures that are around 10 to 100 nanometers in size, or many times smaller than a millionth of an inch. In the future, researchers expect to be able to zoom in and observe even smaller structures. The donut beam, or angular momentum beam of light, also does not damage small electronic equipment during the process, as existing imaging tools such as electron microscopes do.

“In the future, this method could be used to inspect polymers used in semiconductor manufacturing and printing for defects without damaging the structure during the process,” Mahne said. Stated.

Bin Wang and Nathan Brooks, who received their PhDs from JILA in 2023, are the lead authors of this new study.

Pushing the Limits of Microscopy

Mahne said this research pushes the fundamental limits of microscopy. Because of the physics of light, lens-based imaging tools can only see the world to a resolution of about 200 nanometers, which is not precise enough to capture many viruses. For example, those that infect humans. Although scientists can freeze viruses to death and view them with powerful cryo-electron microscopes, they still cannot capture the activity of these pathogens in real time.

Ptychography, developed in the mid-2000s, could help researchers break through that limit.

How ptychography works
To understand how, go back to shadow puppets. Imagine that a scientist wants to collect stylized images of very small structures, perhaps the letters that spell “CU.” To do this, they first shine a laser beam on the text and scan the text multiple times. When light hits “C” and “U” (in this case the dolls), the light rays break and scatter, creating a complex pattern (shadow). Scientists record those patterns using sensitive detectors and analyze them using a series of mathematical formulas. Given enough time, they will perfectly recreate the shape of the doll from the shadow it casts, Mahne explained.

Evolution to Finer Details

Stated. Bin Wang and Nathan Brooks, who received their PhDs from JILA in 2023, are the lead authors of this new study. Other co-authors of the new study include physics professor and JILA fellow Henry Kaptein, current and former JILA graduate students Peter Johnsen, Nicholas Jenkins, Yuka Esashi, Iona Binney, Includes Michael Tanksalvara.

Reference: “High-fidelity ptychographic imaging of highly periodic structures enabled by vortex harmonic beams” Michael Tanksalvala, Henry C. Kapteyn, Bin Wang, Peter Johnsen, Yuka Esashi, Iona Binnie, Margaret M. Murnane, Nicholas W. Jenkins, and Nathan J. Brooks, September 19, 2023, optica.
DOI: doi:10.1364/OPTICA.498619

Source: scitechdaily.com