воскресенье, 20 октября 2019 г.

Azurite | #Geology #GeoloyPage #Minerals Locality:…

Azurite | #Geology #GeoloyPage #Minerals

Locality: Altenmittlau, Freigericht, Spessart Mountains, Hesse, Germany, Europe

Dimensions: 7.0 × 4.8 × 4.0 cm

Photo Copyright © Crystal Classics

Geology Page

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Image of the Week – October 21, 2019CIL:48108 -…

Image of the Week – October 21, 2019


Description: Differentiated rat neural stem cells stained for β III-Tubulin (in green) to reveal neurons, GFAP (in red) to reveal glial cells, and DAPI (in blue) to label nuclei.

Authors: Natalie Prigozhina

Attribution Only: This image is licensed under a Creative Commons Attribution License.

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Growing Gallstones If you’ve been unlucky enough to be…

Growing Gallstones

If you’ve been unlucky enough to be troubled by gallstones, you’ll know how unpleasant they can be. Found in the gallbladder and formed from clumps of chalky salts and cholesterol, they can be as large as a golfball or as small as a grain of sand. And while many people with gallstones don’t have any symptoms, they can cause severe pain and sickness. The simplest treatment is surgery to remove the entire gallbladder, as current medications take a long time to work and often aren’t very effective. One problem with finding new treatments is that researchers don’t fully understand how gallstones form in the first place. A new study shows that sticky ‘nets’ of DNA thrown out by immune cells may be responsible for triggering the growth of gallstones and can be blocked by certain drugs, pointing to a potential new avenue for prevention or treatment for these troublesome stones.

Written by Kat Arney

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ancientpeopleancientplaces:Nether Largie Standing Stone, Kilmartin Glen, Argyll, Pen and...


Nether Largie Standing Stone, Kilmartin Glen, Argyll, Pen and Ink Sketch, October 2019.

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2019 October 20 Pluto at Night Image Credit: NASA, Johns…

2019 October 20

Pluto at Night
Image Credit: NASA, Johns Hopkins Univ./APL, Southwest Research Institute

Explanation: The night side of Pluto spans this shadowy scene, a stunning spacebased view with the Sun 4.9 billion kilometers (almost 4.5 light-hours) behind the dim and distant world. It was captured by far flung New Horizons in July of 2015. The spacecraft was at a range of some 21,000 kilometers from Pluto, about 19 minutes after its closest approach. A denizen of the Kuiper Belt in dramatic silhouette, the image also reveals Pluto’s tenuous, surprisingly complex layers of hazy atmosphere. The crescent twilight landscape near the top of the frame includes southern areas of nitrogen ice plains now formally known as Sputnik Planitia and rugged mountains of water-ice in the Norgay Montes.

∞ Source: apod.nasa.gov/apod/ap191020.html

DARKSuper Spirals Spin Super Fast

Mosaic of Super Spirals 
Credits: Top row: NASA, ESA, P. Ogle and J. DePasquale (STScI)
Bottom row: SDSS, P. Ogle and J. DePasquale (STScI )

When it comes to galaxies, how fast is fast? The Milky Way, an average spiral galaxy, spins at a speed of 130 miles per second (210 km/sec) in our Sun’s neighborhood. New research has found that the most massive spiral galaxies spin faster than expected. These “super spirals,” the largest of which weigh about 20 times more than our Milky Way, spin at a rate of up to 350 miles per second (570 km/sec).

Super spirals are exceptional in almost every way. In addition to being much more massive than the Milky Way, they’re also brighter and larger in physical size. The largest span 450,000 light-years compared to the Milky Way’s 100,000-light-year diameter. Only about 100 super spirals are known to date. Super spirals were discovered as an important new class of galaxies while studying data from the Sloan Digital Sky Survey (SDSS) as well as the NASA/IPAC Extragalactic Database (NED).

“Super spirals are extreme by many measures,” says Patrick Ogle of the Space Telescope Science Institute in Baltimore, Maryland. “They break the records for rotation speeds.”

Ogle is first author of a paper that was published October 10, 2019 in the Astrophysical Journal Letters . The paper presents new data on the rotation rates of super spirals collected with the Southern African Large Telescope (SALT), the largest single optical telescope in the southern hemisphere. Additional data were obtained using the 5-meter Hale telescope of the Palomar Observatory, operated by the California Institute of Technology. Data from NASA’s Wide-field Infrared Survey Explorer (WISE) mission was crucial for measuring the galaxy masses in stars and star formation rates.

Referring to the new study, Tom Jarrett of the University of Cape Town, South Africa says, “This work beautifully illustrates the powerful synergy between optical and infrared observations of galaxies, revealing stellar motions with SDSS and SALT spectroscopy, and other stellar properties — notably the stellar mass or ‘backbone’ of the host galaxies — through the WISE mid-infrared imaging.»

Theory suggests that super spirals spin rapidly because they are located within incredibly large clouds, or halos, of dark matter. Dark matter has been linked to galaxy rotation for decades. Astronomer Vera Rubin pioneered work on galaxy rotation rates, showing that spiral galaxies rotate faster than if their gravity were solely due to the constituent stars and gas. An additional, invisible substance known as dark matter must influence galaxy rotation. A spiral galaxy of a given mass in stars is expected to rotate at a certain speed. Ogle’s team finds that super spirals significantly exceed the expected rotation rate.

Super spirals also reside in larger than average dark matter halos. The most massive halo that Ogle measured contains enough dark matter to weigh at least 40 trillion times as much as our Sun. That amount of dark matter would normally contain a group of galaxies rather than a single galaxy.

“It appears that the spin of a galaxy is set by the mass of its dark matter halo,” Ogle explains.

The fact that super spirals break the usual relationship between galaxy mass in stars and rotation rate is a new piece of evidence against an alternative theory of gravity known as Modified Newtonian Dynamics, or MOND. MOND proposes that on the largest scales like galaxies and galaxy clusters, gravity is slightly stronger than would be predicted by Newton or Einstein. This would cause the outer regions of a spiral galaxy, for example, to spin faster than otherwise expected based on its mass in stars. MOND is designed to reproduce the standard relationship in spiral rotation rates, therefore it cannot explain outliers like super spirals. The super spiral observations suggest no non-Newtonian dynamics is required.

Despite being the most massive spiral galaxies in the universe, super spirals are actually underweight in stars compared to what would be expected for the amount of dark matter they contain. This suggests that the sheer amount of dark matter inhibits star formation. There are two possible causes: 1) Any additional gas that is pulled into the galaxy crashes together and heats up, preventing it from cooling down and forming stars, or 2) The fast spin of the galaxy makes it harder for gas clouds to collapse against the influence of centrifugal force.

“This is the first time we’ve found spiral galaxies that are as big as they can ever get,” Ogle says.

Despite these disruptive influences, super spirals are still able to form stars. Although the largest elliptical galaxies formed all or most of their stars more than 10 billion years ago, super spirals are still forming stars today. They convert about 30 times the mass of the Sun into stars every year, which is normal for a galaxy of that size. By comparison, our Milky Way forms about one solar mass of stars per year.

Ogle and his team have proposed additional observations to help answer key questions about super spirals, including observations designed to better study the motion of gas and stars within their disks. After its 2021 launch, NASA’s James Webb Space Telescope could study super spirals at greater distances and correspondingly younger ages to learn how they evolve over time. And NASA’s WFIRST mission may help locate more super spirals, which are exceedingly rare, thanks to its large field of view.

The Space Telescope Science Institute is expanding the frontiers of space astronomy by hosting the science operations center of the Hubble Space Telescope, the science and operations center for the James Webb Space Telescope, and the science operations center for the future Wide Field Infrared Survey Telescope (WFIRST). STScI also houses the Mikulski Archive for Space Telescopes (MAST) which is a NASA-funded project to support and provide to the astronomical community a variety of astronomical data archives, and is the data repository for the Hubble, Webb, Kepler, K2, TESS missions and more.

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Fluorite | #Geology #GeologyPage #Minerals Locality: Elmwood…

Fluorite | #Geology #GeologyPage #Minerals

Locality: Elmwood Mine, Smith County, Tennessee, United States of America

Size: 2.4 × 2.8 × 1.5 cm

Photo Copyright © Thames Valley Minerals /e-rocks. com

Geology Page

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Fluorite | #Geology #GeologyPage #Minerals Locality: Susten…

Fluorite | #Geology #GeologyPage #Minerals

Locality: Susten Pass, Meien Valley, Uri, Switzerland

Size: 6 × 3.5 × 5 cm

Photo Copyright © HP Minerals /e-rocks. com

Geology Page

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Golden Balls Getting medicine to precisely where it’s needed…

Golden Balls

Getting medicine to precisely where it’s needed in the body is like trying to get a hole-in-one in golf. You have a much better chance of hitting the target if you can nudge it along the way a few times. Now researchers have developed medicine-carrying ball-shaped microbots that can be pushed towards where they’re needed most. Using a new imaging technique that highlights both microbots and tumours in the digestive tract, researchers track the tiny spheres of gold-coated magnesium (pictured). Bubbles shooting out of a hole propel the spheres towards trouble, and when they arrive at the target area the drugs are released as researchers fire a burst of infrared light through the body, melting a waxy sealant layer. This precision approach could make drug delivery much more accurate, making more efficient and effect treatments par for the course.

Written by Anthony Lewis

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ancientpeopleancientplaces:Y Ffor (Four Crosses) Prehistoric Burial Chamber, North Wales,...


Y Ffor (Four Crosses) Prehistoric Burial Chamber, North Wales, Pen and Ink Sketch, October 2019.

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Fluorite | #Geology #GeologyPage #Minerals Locality: Berbes,…

Fluorite | #Geology #GeologyPage #Minerals

Locality: Berbes, Ribadesella, Asturias, Spain

Size: 8.5 × 7.4 × 4 cm

Photo Copyright © Viamineralia /e-rocks. com

Geology Page

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https://t.co/hvL60wwELQ — XissUFOtoday Space (@xufospace) August 3, 2021 Жаждущий ежик наслаждается пресной водой после нескольких дней в о...