вторник, 18 июня 2019 г.

Two Earth-like planets around one of the smallest stars, and a slim chance someone there...

An international team of astronomers has found two Earth-like planets around one of the smallest known stars known as “Teegarden’s star.” The planets, which orbit in the star’s habitable zone where liquid water is possible, are only a quarter and a third more massive than the Earth, respectively. The discovery helps complete our picture of the statistics of exoplanet prevalence, correcting implicit biases in earlier observations. Incidentally, hypothetical observers on those planets would soon be in a uniquely favorable position to detect our Earth, using the so-called transit method. The results have just been published in the journal Astronomy & Astrophysics.

By now, astronomers have detected more than 4000 exoplanets, that is, planets orbiting stars other than the Sun. But our view of the alien worlds out there is highly biased. The standard methods of (indirectly) detecting exoplanets all require precise measurements of the host star’s light, and such measurements are much easier for stars that are about as bright as our Sun. Most stars within our galaxy are dimmer and more reddish than that, and for those stars, exoplanet detection has been difficult – potentially biasing the conclusions astronomers might want to draw about the prevalence and properties of exoplanets in general!

The CARMENES instrument at Calar Alto Observatory, which saw “first light” in early 2016, is a twin spectrograph optimized for targeting just such dim, reddish stars. Martin Kürster, leading scientist for CARMENES at the Max Planck Institute for Astronomy, says: “CARMENES can help us correct our biases by studying the by far most common stars in our galaxy. The instrument is sensitive enough to detect Earth-like, potentially habitable planets around such stars.”

One of the more than 300 red dwarf stars targeted by CARMENES was “Teegarden’s star,” in the constellation Aries, named for NASA scientist Bonnard J. Teegarden who found the star in data that had been collected for tracking asteroids. With just 8% of the Sun’s mass, around 10% of the Sun’s radius and a reddish 2900 K in temperature, Teegarden’s star is one of the smallest stars in our neigbourhood. At a distance of just 12.5 light-years, it is also one of the closest stars. Following the usual conventions, the two planets have been designated «Teegarden b» and «Teegarden c».

Mathias Zechmeister of Göttingen University (formerly at MPIA), lead author of the study, says: “We observed this star for three years, looking for periodic variations in its velocity. The data clearly show the existence of two planets.” Following the usual naming conventions, the planets have been designated Teegarden b and Teegarden c.

The so-called radial velocity method used for the detection allows for the measurement of a planets’ minimum mass, and estimates for their probable mass. The planets around Teegarden’s star have minimum masses of 1.05 and 1.1 Earth masses, respectively, with best mass estimates of 1.25 and 1.33 Earth masses, making them somewhat Earth-like. Both planets orbit inside their star’s habitable zone, where liquid water is possible, although one of the planets would need to have a rather special atmosphere in order to allow for water on its surface. Estimates put the system’s age at around 8 billion years, nearly twice as old as Earth, allowing plenty of time for the evolution of life.

Incidentally, within a few decades, it would be easier for hypothetical intelligent beings on one of those planets to detect Earth than the other way around: Between the years 2044 and 2496, Teegarden’s star will be positioned to see the Solar System edge on, and its inhabitants should be able to detect Earth using the so-called transit method as they see our planet pass directly in front of the disk of the Sun.

By that time, Earth’s astronomers can be expected to have raised the stakes already: the similarities to Earth and potential habitability make the two planets prime candidates for further in-depth study by the next generation of Earth-based telescopes, in pursuit of one of the most exciting goals of modern astronomy: detecting life on another planet.

Science Contact

Martin Kürster
Head of the Technical Departments, Project Coordinator, Astronomer
Phone: +49 6221 528-214
Email: kuerster@mpia.de
Room: 123

Links:  Technischen Abteilungen Technical Departments

Public Information Officer

Markus Pössel
Public Information Officer
Phone:+49 6221 528-261
Email: pr@mpia.de

Background information

The results have been published as M. Zechmeister et al. 2019, “The CARMENES search for exoplanets around M dwarfs: Two temperate Earth-mass planet candidates around Teegarden’s Star” in the journal Astronomy & Astrophysics.

The CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) instrument is a high-resolution optical and near infrared spectrograph. The project is carried out by the universities of Göttingen, Hamburg, Heidelberg, and Madrid, the Max-Planck Institut für Astronomie Heidelberg, Institutes of the Consejo Superior de Investigaciones Científicas in Barcelona, Granada, and Madrid, Thüringer Landessternwarte, Instituto de Astrofísica de Canarias, and Calar-Alto Observatory. In the framework of CARMENES, German and Spanish scientists have been searching for planets around stars in the solar neighbourhood since 2016. The new planets are number ten and eleven among the project’s discoveries.

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2019 June 18 Strawberry Moon over the Temple of Poseidon Image…

2019 June 18

Strawberry Moon over the Temple of Poseidon
Image Credit & Copyright: Elias Chasiotis

Explanation: Did you see the full moon last night? If not, tonight’s nearly full moon should be almost as good. Because full moons are opposite the Sun, they are visible in the sky when the Sun is not – which should be nearly all night long tonight, clouds permitting. One nickname for June’s full moon is the Strawberry Moon, named for when wild strawberries start to ripen in parts of Earth’s northern hemisphere. Different cultures around the globe give this full moon different names, though, including Honey Moon and Rose Moon. In the foreground of this featured image, taken yesterday in Cape Sounion, Greece, is the 2,400 year-old Temple of Poseidon. Next month will the 50th anniversary of the time humans first landed on the Moon.

∞ Source: apod.nasa.gov/apod/ap190618.html

Final Week for Station Trio as Science Continues Unabated

ISS — Expedition 59 Mission patch.

June 17, 2019

Three Expedition 59 crewmembers are beginning their final week aboard the International Space Station and readying their spacesuits and Soyuz crew ship for the return to Earth. The orbital residents also continued a variety of human research activities amidst the deployment of tiny satellites today.

Flight Engineers Anne McClain and David Saint-Jacques are set to return to Earth June 24 with Commander Oleg Kononenko at the helm of the Soyuz MS-11 crew craft. The homebound residents checked their Sokol launch and entry suits for leaks today. The trio also tested sensors that will monitor the crew’s blood pressure during reentry into Earth’s atmosphere.

Image above: The Expedition 59 crewmembers gather for a portrait inside Japan’s Kibo laboratory module. Front row from left are David Saint-Jacques, Oleg Kononenko and Anne McClain who are returning to Earth June 24. In the back are Christina Koch, Alexey Ovchinin and Nick Hague. Image Credit: NASA.

McClain also packed personal items she will take back to Earth with her. Kononenko and Saint-Jacques practiced Soyuz descent procedures the crew will use on its way to a landing in Kazakhstan. The threesome have been living aboard the space lab since Dec. 3 and will have accumulated 204 days on orbit when they complete their mission next week.

Science continues unabated aboard the orbital lab with the crew exploring a wide variety of phenomena to help NASA plan missions to the Moon, Mars and beyond. Payload specialists on the ground also remotely operate many of the hundreds of experiments taking place aboard the orbiting lab.

International Space Station (ISS).  Animation Credit: NASA

NASA astronaut Christina Koch started Monday researching how microgravity affects perception and orientation. Today’s experiment session required Koch to perform simple tasks wearing a neck brace and virtual reality goggles while free-floating inside Europe’s Columbus laboratory module.

Four small satellites, or CubeSats, were ejected this morning outside of Japan’s Kibo laboratory module. Flight Engineer Nick Hague of NASA monitored and photographed the CubeSats deployed for technology demonstrations. The first set of CubeSats deployed were from Nepal, Sri Lanka and Japan as part of the BIRDS-3 mission. The last CubeSat was from Singapore. All four arrived at the station April 19 aboard the Northrop Grumman Cygnus space freighter.

Related links:

Expedition 59: https://www.nasa.gov/mission_pages/station/expeditions/expedition59/index.html

Perception and orientation: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Investigation.html?#id=7484

Columbus laboratory module: https://www.nasa.gov/mission_pages/station/structure/elements/europe-columbus-laboratory

CubeSats: https://www.nasa.gov/cubesats

Kibo laboratory module: https://www.nasa.gov/mission_pages/station/structure/elements/japan-kibo-laboratory

Space Station Research and Technology: https://www.nasa.gov/mission_pages/station/research/index.html

International Space Station (ISS): https://www.nasa.gov/mission_pages/station/main/index.html

Image (mentioned), Animation (mentioned), Text, Credits: NASA/Mark Garcia.

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ATLAS homes in on magnetic monopoles

CERN — ATLAS Experiment logo.

17 June, 2019

The ATLAS collaboration has placed some of the tightest limits yet on the production rate of hypothetical particles known as magnetic monopoles 

Magnetic monopoles (larger image) and magnetic dipole (inset) (Image: CERN)

Break a magnet in two, no matter how small, and you’ll get two magnets, each with a south and a north pole of opposite magnetic nature. However, some theories predict particles with an isolated magnetic pole, which would carry a magnetic charge analogous to a positive or negative electric charge. But despite many searches, such magnetic monopoles have never been spotted at particle colliders. A new search by the ATLAS collaboration at CERN places some of the tightest bounds yet on the production rate of these hypothetical particles. These results are complementary to those from CERN’s MoEDAL experiment, which is specifically designed to search for magnetic monopoles.

Originally proposed in 1931 by physicist Paul Dirac, magnetic monopoles have since been shown to be an outcome of so-called grand unified theories (GUTs) of particle physics, which connect fundamental forces at high energies into a single force. Such GUT monopoles typically have masses that are too high for them to be spotted at particle colliders, but some extensions of the Standard Model predict monopoles with masses that could be in a range accessible to colliders.

The latest ATLAS search is based on data from proton–proton collisions produced at the Large Hadron Collider at an energy of 13 TeV. The collaboration looked for signs in the data of large energy deposits that would be left behind by the magnetic monopoles in the ATLAS particle detector. The energy deposits would be proportional to their magnetic charge squared. Such large deposits are also an expected signature of high-electric-charge objects (HECOs), which may include mini black holes, so the search was also sensitive to HECOs.

The team found no sign of magnetic monopoles or HECOs in the data but improved previous work on several fronts. Firstly, the search achieves improved limits on the production rate of monopoles that carry one or two units of a fundamental magnetic charge called Dirac charge. The new limits surpass those from MoEDAL, although MoEDAL is sensitive to a larger range of magnetic charge – up to five Dirac charges – and can probe monopoles produced by two mechanisms, whereas ATLAS probed only one. MoEDAL researchers are also working towards pushing the experiment to probe monopoles with magnetic charges well beyond five Dirac charges.

In addition, the ATLAS search improves limits on the production of HECOs with electric charge between 20 and 60 times the charge of the electron. Finally, the search is the first to probe HECOs with charges greater than 60 times the electron charge, surpassing the charge probed by previous searches by ATLAS and also by the CMS collaboration.

For more information about these results, see the ATLAS website: https://atlas.cern/updates/physics-briefing/new-result-magnetic-monopoles


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related links:

ATLAS collaboration: https://atlas.cern/

MoEDAL experiment: https://home.cern/science/experiments/moedal

Standard Model: https://home.cern/science/physics/standard-model

Large Hadron Collider (LHC): https://home.cern/science/accelerators/large-hadron-collider

CMS collaboration: https://cms.cern/

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Image (mentioned), Text, Credits: CERN/ Ana Lopes.

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The Star Trek logo was discovered on Mars

NASA — Mars Reconnaissance Orbiter (MRO) logo / Star Trek logo.

June 17, 2019

When science fiction meets reality … we are left speechless. A strange shape strongly resembling the Star Trek logo was photographed on Mars by NASA.

NASA’s  MRO spots ‘Star Trek’ symbol on Mars. Image Credits: NASA/JPL-Caltech/MRO

On Wednesday, June 12, the US Space Organization and the University of Arizona released a snapshot taken by the Mars Orbiter reconnaissance probe. In this photo we can see a fairly triangular shape strongly reminiscent of the iconic logo of the series and movies Star Trek.

Artist’s view of Mars Reconnaissance Orbiter (MRO). Image Credits: NASA/JPL-Caltech

While fans are eager to believe that Vulcans exist in our universe, the US agency ensures that «it’s a coincidence.» NASA explains that «these strange chevron shapes in the south-west of Hellas Planitia are the result of a complex story between dunes, lava and wind. A long time ago, three large crescent-shaped dunes moved to this area, and one day there was an eruption. The lava spread on the ground and around the dunes, but did not cover them «.

Twitter message of William Shatner. Image Credit: Twitter

Very active on Twitter, the actor William Shatner, the historical Kirk, quickly reacted, explaining that «Star Trek» was stronger than «Star Wars».

Mars Reconnaissance Orbiter (MRO): https://mars.nasa.gov/mro/

Images (mentioned), Text, Credits: NASA/Orbiter.ch Aerospace/Roland Berga.

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Liddicoatite with Quartz | #Geology #GeologyPage…

Liddicoatite with Quartz | #Geology #GeologyPage #Mineral

Locality: Tokambohitra, Sahatany Valley, Vakinankaratra Region, Antananarivo Province, Madagascar

Size: 6.2 x 3.2 x 2.6 cm

Photo Copyright © Saphira Minerals

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Eldredgeops Trilobite Fossil

Eldredgeops Trilobite Fossil

Pseudogygites latimarginatus Trilobite Fossil

Pseudogygites latimarginatus Trilobite Fossil

Roman Gardens and Baths, Chester, Cheshire, 15.6.19.

Roman Gardens and Baths, Chester, Cheshire, 15.6.19.

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Roman Bathhouse, Chester Roman Gardens, Chester, Cheshire, 15.6.19.

Roman Bathhouse, Chester Roman Gardens, Chester, Cheshire, 15.6.19.

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NASA Scientists Find Sun’s History Buried in Moon’s Crust

NASA — Space Weather logo.

June 17, 2019


— The Sun’s rotation rate in its first billion years is unknown.

— Yet, this spin rate affected solar eruptions, influencing the evolution of life.

— A team of NASA scientists think they’ve figured it out by using the Moon as critical evidence.

Image above: NASA’s Solar Dynamics Observatory captured this image of a solar flare on Oct. 2, 2014. The solar flare is the bright flash of light on the right limb of the Sun. A burst of solar material erupting out into space can be seen just below it. Image Credits: NASA/SDO.

The Sun is why we’re here. It’s also why Martians or Venusians are not.

When the Sun was just a baby four billion years ago, it went through violent outbursts of intense radiation, spewing scorching, high-energy clouds and particles across the solar system. These growing pains helped seed life on early Earth by igniting chemical reactions that kept Earth warm and wet. Yet, these solar tantrums also may have prevented life from emerging on other worlds by stripping them of atmospheres and zapping nourishing chemicals. 

Just how destructive these primordial outbursts were to other worlds would have depended on how quickly the baby Sun rotated on its axis. The faster the Sun turned, the quicker it would have destroyed conditions for habitability. 

This critical piece of the Sun’s history, though, has bedeviled scientists, said Prabal Saxena, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Saxena studies how space weather, the variations in solar activity and other radiation conditions in space, interacts with the surfaces of planets and moons.

Now, he and other scientists are realizing that the Moon, where NASA will be sending astronauts by 2024, contains clues to the ancient mysteries of the Sun, which are crucial to understanding the development of life.

Animation above: An animated .gif created from images of the Sun taken by NASA’s Solar Dynamics Observatory, which observes the Sun 24/7. This image shows the Sun in a wavelength (171 angstrom) of ultraviolet light. Animation Credits: NASA/SDO.

“We didn’t know what the Sun looked like in its first billion years, and it’s super important because it likely changed how Venus’ atmosphere evolved and how quickly it lost water. It also probably changed how quickly Mars lost its atmosphere, and it changed the atmospheric chemistry of Earth,” Saxena said.   

The Sun-Moon Connection

Saxena stumbled into investigating the early Sun’s rotation mystery while contemplating a seemingly unrelated one: Why, when the Moon and Earth are made of largely the same stuff, is there significantly less sodium and potassium in lunar regolith, or Moon soil, than in Earth soil?  

This question, too, revealed through analyses of Apollo-era Moon samples and lunar meteorites found on Earth, has puzzled scientists for decades — and it has challenged the leading theory of how the Moon formed.   

Our natural satellite took shape, the theory goes, when a Mars-sized object smashed into Earth about 4.5 billion years ago. The force of this crash sent materials spewing into orbit, where they coalesced into the Moon. 

Image above: A closeup view of Apollo 16 lunar sample no. 68815, a dislodged fragment from a parent boulder roughly four feet high and five feet long. Image Credits: NASA/JSC.

“The Earth and Moon would have formed with similar materials, so the question is, why was the Moon depleted in these elements?” said Rosemary Killen, an planetary scientist at NASA Goddard who researches the effect of space weather on planetary atmospheres and exospheres.  

The two scientists suspected that one big question informed the other — that the history of the Sun is buried in the Moon’s crust.  

Killen’s earlier work laid the foundation for the team’s investigation. In 2012, she helped simulate the effect solar activity has on the amount of sodium and potassium that is either delivered to the Moon’s surface or knocked off by a stream of charged particles from the Sun, known as the solar wind, or by powerful eruptions known as coronal mass ejections.

Saxena incorporated the mathematical relationship between a star’s rotation rate and its flare activity. This insight was derived by scientists who studied the activity of thousands of stars discovered by NASA’s Kepler space telescope: The faster a star spins, they found, the more violent its ejections. “As you learn about other stars and planets, especially stars like our Sun, you start to get a bigger picture of how the Sun evolved over time,” Saxena said. 

Using sophisticated computer models, Saxena, Killen and colleagues think they may have finally solved both mysteries. Their computer simulations, which they described on May 3 in the The Astrophysical Journal Letters, show that the early Sun rotated slower than 50% of baby stars. According to their estimates, within its first billion years, the Sun took at least 9 to 10 days to complete one rotation. 

They determined this by simulating the evolution of our solar system under a slow, medium, and then a fast-rotating star. And they found that just one version — the slow-rotating star — was able to blast the right amount of charged particles into the Moon’s surface to knock enough sodium and potassium into space over time to leave the amounts we see in Moon rocks today.  

“Space weather was probably one of the major influences for how all the planets of the solar system evolved,” Saxena said, “so any study of habitability of planets needs to consider it.”

Life Under the Early Sun

The rotation rate of the early Sun is partly responsible for life on Earth. But for Venus and Mars — both rocky planets similar to Earth — it may have precluded it. (Mercury, the closest rocky planet to the Sun, never had a chance.)

Earth’s atmosphere was once very different from the oxygen-dominated one we find today. When Earth formed 4.6 billion years ago, a thin envelope of hydrogen and helium clung to our molten planet. But outbursts from the young Sun stripped away that primordial haze within 200 million years.

As Earth’s crust solidified, volcanoes gradually coughed up a new atmosphere, filling the air with carbon dioxide, water, and nitrogen. Over the next billion years, the earliest bacterial life consumed that carbon dioxide and, in exchange, released methane and oxygen into the atmosphere. Earth also developed a magnetic field, which helped protect it from the Sun, allowing our atmosphere to transform into the oxygen- and nitrogen-rich air we breathe today.

“We were lucky that Earth’s atmosphere survived the terrible times,” said Vladimir Airapetian, a senior Goddard heliophysicist and astrobiologist who studies how space weather affects the habitability of terrestrial planets. Airapetian worked with Saxena and Killen on the early Sun study.

Image above: An artistic conception of the early Earth, showing a surface pummeled by large impact, resulting in extrusion of deep-seated magma onto the surface. Image Credit: Simone Marchi.

Had our Sun been a fast rotator, it would have erupted with super flares 10 times stronger than any in recorded history, at least 10 times a day. Even Earth’s magnetic field wouldn’t have been enough to protect it. The Sun’s blasts would have decimated the atmosphere, reducing air pressure so much that Earth wouldn’t retain liquid water. “It could have been a much harsher environment,” Saxena noted.

But the Sun rotated at an ideal pace for Earth, which thrived under the early star. Venus and Mars weren’t so lucky. Venus was once covered in water oceans and may have been habitable. But due to many factors, including solar activity and the lack of an internally generated magnetic field, Venus lost its hydrogen — a critical component of water. As a result, its oceans evaporated within its first 600 million years, according to estimates. The planet’s atmosphere became thick with carbon dioxide, a heavy molecule that’s harder to blow away. These forces led to a runaway greenhouse effect that keeps Venus a sizzling 864 degrees Fahrenheit (462 degrees Celsius), far too hot for life.

Mars, farther from the Sun than Earth is, would seem to be safer from stellar outbursts. Yet, it had less protection than did Earth. Due partly to the Red Planet’s weak magnetic field and low gravity, the early Sun gradually was able to blow away its air and water. By about 3.7 billion years ago, the Martian atmosphere had become so thin that liquid water immediately evaporated into space. (Water still exists on the planet, frozen in the polar caps and in the soil.)

After influencing the course for life (or lack thereof) on the inner planets, the aging Sun gradually slowed its pace and continues to do so. Today, it revolves once every 27 days, three times slower than it did in its infancy. The slower spin renders it much less active, though the Sun still has violent outbursts occasionally.

Exploring the Moon, Witness of Solar System Evolution

To learn about the early Sun, Saxena said, you need to look no further than the Moon, one of the most well-preserved artifacts from the young solar system. 

“The reason the Moon ends up being a really useful calibrator and window into the past is that it has no annoying atmosphere and no plate tectonics resurfacing the crust,” he said. “So as a result, you can say, ‘Hey, if solar particles or anything else hit it, the Moon’s soil should show evidence of that.»

LRO Peers into Permanent Lunar Shadows

Video above: Visualization of the Moon’s permanently shadowed regions, or PSRs, using images taken by NASA’s Lunar Reconnaissance Orbiter. PSRs are places on the Moon that haven’t seen the Sun in millions, or even billions, of years. While the Earth’s tilted axis allows sunlight to fall everywhere on its surface, even at the poles, for at least part of the year, the Moon’s tilt relative to the Sun is only 1.6°, not enough to get sunlight into some deep craters near the lunar north and south poles. PSRs are therefore some of the coldest, darkest places in the solar system. Video Credits: NASA Goddard/Ernie Wright.

Apollo samples and lunar meteorites are a great starting point for probing the early solar system, but they are only small pieces in a large and mysterious puzzle. The samples are from a small region near the lunar equator, and scientists can’t tell with complete certainty where on the Moon the meteorites came from, which makes it hard to place them into geological context.

Since the South Pole is home to the permanently shadowed craters where we expect to find the best-preserved material on the Moon, including frozen water, NASA is aiming to send a human expedition to the region by 2024. 

If astronauts can get samples of lunar soil from the Moon’s southernmost region, it could offer more physical evidence of the baby Sun’s rotation rate, said Airapetian, who suspects that solar particles would have been deflected by the Moon’s erstwhile magnetic field 4 billion years ago and deposited at the poles: “So you would expect — though we’ve never looked at it — that the chemistry of that part of the Moon, the one exposed to the young Sun, would be much more altered than the equatorial regions. So there’s a lot of science to be done there.»

Related links:

Earth’s Moon: http://www.nasa.gov/moon

Sun: http://www.nasa.gov/sun

Moon to Mars: https://www.nasa.gov/topics/moon-to-mars/

Space Weather: https://www.nasa.gov/subject/3165/space-weather

Artemis: https://www.nasa.gov/subject/16957/artemis

Solar Dynamics Observatory (SDO): https://www.nasa.gov/mission_pages/sdo/main/index.html

The Astrophysical Journal Letters: https://iopscience.iop.org/article/10.3847/2041-8213/ab18fb/meta

Images (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA/Svetlana Shekhtman/Goddard Space Flight Center, by Lonnie Shekhtman and Miles Hatfield.

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    Солнечное затмение 14 декабря 2020 года  — полное  солнечное затмение  142  сароса , которое лучше всего будет видно в юго-восточной час...