среда, 12 июня 2019 г.

Giant Elk Skeleton, Prehistoric Child and Auroch Footprint Casts from Sefton and Replica...

Giant Elk Skeleton, Prehistoric Child and Auroch Footprint Casts from Sefton and Replica of the Calderstones Cup and Ring Rock Art, The Museum of Liverpool, 11.6.19.








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Hera asteroid mission’s brain to be radiation-hard and failure-proof


ESA — Hera Mission logo.


12 June 2019


At the heart of ESA’s Hera mission to the double Didymos asteroids will be an onboard computer intended to be failure-proof.


Designed to operate up to 490 million km away from Earth and withstanding four years of harsh radiation exposure, Hera’s computer must run smoothly without locking up or crashing – on pain of mission failure, while pushing the limits of onboard autonomy.



Hera surveying Didymos

Development of the Hera mission for planetary defence is taking place across Europe, to finalise a ready-to-build design to present to Europe’s space ministers at the Space19+ Ministerial Council this November. Hera’s onboard computer is being overseen by QinetiQ Space in Belgium, also the makers of the Proba family of technology-testing minisatellites.



Hera onboard computer

Peter Holsters of QinetiQ Space explains: “A popular analogy is that if a satellite’s platform is like a bus – with the science-generating payloads like passengers on its seats – then the onboard computer is the driver of the bus. It is the brain of the entire mission, coordinating and operating the various onboard systems and payloads.”


Beyond Earth orbit


The challenge is that this particular onboard computer will be operating much further away than a typical mission in Earth orbit. In order to intercept the Didymos pair of near-Earth asteroids the desk-sized spacecraft will be venturing far into deep space, slightly beyond the orbit of Mars.



Space radiation

“Going so far away means operating in a different radiation environment for a start, which requires very careful component selection as well as specific software strategies,” adds Peter.


Beyond the protection of Earth’s magnetic field, space is riddled with charged particles from the wider cosmos, as well as solar storms from our own Sun. These particles are energetic enough to pass through surface shielding to ‘flip’ individual memory bits – potentially corrupting computer memory – or do permanent damage called ‘latch-ups’, equivalent to tiny short circuits.


“Our computers use flash memory – the same as in your own laptop or smartphone – but we perform rigorous radiation testing to ensure the batches we use meet the necessary performance standards,” adds Peter.



Computer testing

“The next level of managing the problem is on the software side, with speedy error detection and checking in the memory management, including the ability to identify and work around ‘bad blocks’ in memory.”


Venturing far from the Sun also means the onboard computer – like the spacecraft as a whole – will have to get by on less power than in its home planet’s orbit, as available sunshine shrinks.


Pushing the boundaries of autonomy


As for all deep-space missions, support from ground control will be constrained as well. The sheer distance involved means that real-time control will not be feasible. Hera’s computer will be capable of making many of its own decisions. In addition, in the complex double asteroid environment of Didymos, switching into safe mode during critical close-proximity operations must be avoided.



Hera mission timeline

“In Earth orbit a mission’s computer going into safe mode is no big deal – the satellite itself is not going anywhere, there’s time to reconfigure it,” says Peter. “But in deep space, with big asteroids whirling around, any recovery from failure will have to be done autonomously, and as quickly as possible.


“That implies maximum redundancy and fast switch-over times from the failing element to its backup. We actually have good experience of such hot redundancy from another company project: developing a safety-critical docking mechanism according to the International Birthing and Docking Mechanism Standard, which is used for making the connection between crewed and uncrewed spacecraft on one end and the International Space Station or in future the Lunar Gateway station, on the other.



Processor module

”Our benchmark for Hera is that reconfiguration from any computer failure should be extremely fast, a matter of 10 to 20 seconds.


“Another design strategy is to deliberately not have all the functionality in the central onboard computer. On Hera the image processing – which can potentially be used for autonomous spacecraft navigation – will be performed by a dedicated unit, being developed by GMV in Romania.”


It’s a similar approach to having a separate graphics card to make your home computer run video games better – avoiding clogging up the computer with computationally intensive but non-core tasks.


From the Proba fold


Hera’s computer will run on a powerful dual-core LEON-3 processor – part of a family of ESA-developed microprocessors for space. Its overall design is developed from the ADPMS – Advanced Data and Power Management System – computer flown on Proba-2, Proba-V and the forthcoming Proba-3 mini-satellites. This computer has demonstrated more than 15 years of in-orbit operations with very high reliability.



Proba-V satellite

“We’ve reached the engineering model phase of our upgraded ADPMS design, which will serve the Altius ozone-monitoring mission as well as Hera.



Proba-3

“This testing – supported through ESA’s General Support Technology Programme – is taking place under our ProbaNEXT project, which is developing our next-generation Proba platform for a wide variety of uses and users.



Hera mission

“Currently, we are qualifying the redundancy and fast switch-over time element of the design. This testing is allowing us to demonstrate all relevant functioning that Hera needs, so once the decision is made to fly the mission then we will be ready.”


Related links:


Space19+: http://blogs.esa.int/space19plus/


International Birthing and Docking Mechanism Standard: http://www.esa.int/Our_Activities/Human_and_Robotic_Exploration/Dream_Chaser_to_use_Europe_s_next-generation_docking_system


LEON-3 processor: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Father_of_the_chips_steering_Europe_s_space_missions


ESA’s General Support Technology Programme: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Shaping_the_Future/About_the_General_Support_Technology_Programme_GSTP


GMV: http://www.gmv.com/en


Self-driving spacecraft set for planetary defence expedition: http://www.esa.int/Our_Activities/Space_Safety/Hera/Self-driving_spacecraft_set_for_planetary_defence_expedition


ESA’s Hera asteroid mission borrows eyes of NASA’s Dawn: http://www.esa.int/Our_Activities/Space_Safety/Hera/ESA_s_Hera_asteroid_mission_borrows_eyes_of_NASA_s_Dawn


Radiation: satellites’ unseen enemy: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Radiation_satellites_unseen_enemy


Proba Missions: http://www.esa.int/Our_Activities/Space_Engineering_Technology/Proba_Missions


QinetiQ Space Belgium: https://www.qinetiq.com/What-we-do/Space


Hera: http://www.esa.int/Our_Activities/Space_Safety/Hera


Images, Video, Text, Credits: ESA/P.Carril/ScienceOffice.org/QinetiQ Space/ESA/NASA/SOHO.


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Mass Anomaly Detected Under The Moon’s Largest Crater


NASA — GRAIL Mission patch.


June 12, 2019


A mysterious large mass of material has been discovered beneath the largest crater in our solar system — the Moon’s South Pole-Aitken basin — and may contain metal from the asteroid that crashed into the Moon and formed the crater, according to a Baylor University study.


«Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That’s roughly how much unexpected mass we detected,» said lead author Peter B. James,


Ph.D., assistant professor of planetary geophysics in Baylor’s College of Arts & Sciences. The crater itself is oval-shaped, as wide as 2,000 kilometers — roughly the distance between Waco, Texas, and Washington, D.C. — and several miles deep. Despite its size, it cannot be seen from Earth because it is on the far side of the Moon.



Image above: This false-color graphic shows the topography of the far side of the Moon. The warmer colors indicate high topography and the bluer colors indicate low topography. The South Pole-Aitken (SPA) basin is shown by the shades of blue. The dashed circle shows the location of the mass anomaly under the basin. Image Credits: NASA/Goddard Space Flight Center/University of Arizona.


The study — «Deep Structure of the Lunar South Pole-Aitken Basin» — is published in the journal Geophysical Research Letters.


To measure subtle changes in the strength of gravity around the Moon, researchers analyzed data from spacecrafts used for the National Aeronautics and Space Administration (NASA) Gravity Recovery and Interior Laboratory (GRAIL) mission.


«When we combined that with lunar topography data from the Lunar Reconnaissance Orbiter, we discovered the unexpectedly large amount of mass hundreds of miles underneath the South Pole-Aitken basin,» James said. «One of the explanations of this extra mass is that the metal from the asteroid that formed this crater is still embedded in the Moon’s mantle.»


The dense mass — «whatever it is, wherever it came from» — is weighing the basin floor downward by more than half a mile, he said. Computer simulations of large asteroid impacts suggest that, under the right conditions, an iron-nickel core of an asteroid may be dispersed into the upper mantle (the layer between the Moon’s crust and core) during an impact.


«We did the math and showed that a sufficiently dispersed core of the asteroid that made the impact could remain suspended in the Moon’s mantle until the present day, rather than sinking to the Moon’s core,» James said.


Another possibility is that the large mass might be a concentration of dense oxides associated with the last stage of lunar magma ocean solidification.


James said that the South Pole-Aitken basin — thought to have been created about 4 billion years ago — is the largest preserved crater in the solar system. While larger impacts may have occurred throughout the solar system, including on Earth, most traces of those have been lost.



Image above: Using a precision formation-flying technique, the twin GRAIL spacecraft mapped the moon’s gravity field, as depicted in this artist’s rendering. Image credits: NASA/JPL-Caltech.


James called the basin «one of the best natural laboratories for studying catastrophic impact events, an ancient process that shaped all of the rocky planets and moons we see today.»


*This research was supported through the NASA Gravity Recovery and Interior Laboratory (GRAIL) science team.


Co-researchers were David E. Smith, Ph.D., principal investigator for the Lunar Orbiter Laser Altimeter onboard the Lunar Reconnaissance Orbiter; Paul K. Byrne, Ph.D., North Carolina State University; Jordan D. Kendall, Ph.D., Goddard Space Flight Center; H. Jay Melosh, Ph.D., Purdue University; and Maria T. Zuber, Ph.D., GRAIL principal investigator.


NASA Gravity Recovery and Interior Laboratory (GRAIL): https://www.nasa.gov/mission_pages/grail/main/index.html


Images (mentioned), Text, Credits: NASA/Spaceref.com/Keith Cowing.


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Caption Spotlight (12 June 2019): Dune Footprints in HellasThese…


Caption Spotlight (12 June 2019): Dune Footprints in Hellas


These curious chevron shapes in southeast Hellas Planitia are the result of a complex story of dunes, lava, and wind.


Long ago, there were large crescent-shaped (barchan) dunes that moved across this area, and at some point, there was an eruption. The lava flowed out over the plain and around the dunes, but not over them. The lava solidified, but these dunes still stuck up like islands. However, they were still just dunes, and the wind continued to blow. Eventually, the sand piles that were the dunes migrated away, leaving these “footprints” in the lava plain. These are also called “dune casts” and record the presence of dunes that were surrounded by lava.


Enterprising viewers will make the discovery that these features look conspicuously like a famous logo: and you’d be right, but it’s only a coincidence.


NASA/JPL/University of Arizona


Fluorite on Feldspar | #Geology #GeologyPage…


Fluorite on Feldspar | #Geology #GeologyPage #Mineral


Locality: Mont Blanc Massif, Chamonix, Haute-Savoie, Rhone-Alpes, France


Size: 5.3 x 4.4 x 2.7 cm


Photo Copyright © Saphira Minerals


Geology Page

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Aquamarine with Schorl and Feldspar | #Geology #GeologyPage…


Aquamarine with Schorl and Feldspar | #Geology #GeologyPage #Mineral


Locality: Shigar valley, Skardu District, Baltistan, Northern Areas, Pakistan


Size: 9.7 x 8.3 x 3.8 cm


Photo Copyright © Saphira Minerals


Geology Page

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2019 June 12 Spiral Galaxy M96 from Hubble Image Credit: NASA,…


2019 June 12


Spiral Galaxy M96 from Hubble
Image Credit: NASA, ESA, Hubble; Processing & Copyright: Leo Shatz


Explanation: Dust lanes seem to swirl around the core of Messier 96 in this colorful, detailed portrait of the center of a beautiful island universe. Of course M96 is a spiral galaxy, and counting the faint arms extending beyond the brighter central region, it spans 100 thousand light-years or so, making it about the size of our own Milky Way. M96, also known as NGC 3368, is known to be about 35 million light-years distant and a dominant member of the Leo I galaxy group. The featured image was taken by the Hubble Space Telescope. The reason for M96’s asymmetry is unclear – it could have arisen from gravitational interactions with other Leo I group galaxies, but the lack of an intra-group diffuse glow seems to indicate few recent interactions. Galaxies far in the background can be found by examining the edges of the picture.


∞ Source: apod.nasa.gov/apod/ap190612.html


NASA’s SET Mission to Study Satellite Protection Is Ready for Launch


NASA Goddard Space Flight Center logo.


June 11, 2019


Ready, SET, go — NASA’s Space Environment Testbeds, or SET, will launch in June 2019 on its mission to study how to better protect satellites in space. SET will get a ride to space on a U.S. Air Force Research Lab spacecraft aboard a SpaceX Falcon Heavy rocket from NASA’s Kennedy Space Center in Florida.



Image above: SET is an experiment aboard the DSX spacecraft. In this animated image, it is a slender rectangular box, positioned on the far right of DSX’s surface. Image Credits: NASA’s Goddard Space Flight Center/CIL.


SET studies the very nature of space itself — which isn’t completely empty, but brimming with radiation — and how it affects spacecraft and electronics in orbit. Energetic particles from the Sun or deep space can spark memory damage or computer upsets on spacecraft, and over time, degrade hardware. SET seeks to better understand these effects in order to improve spacecraft design, engineering, and operations, and avoid future anomalies. Spacecraft protection is a key part of NASA’s mission as the agency’s Artemis program seeks to explore the Moon and beyond. 


“Since space radiation is one of the primary hazards space missions encounter, researching ways to improve their abilities to survive in these harsh environments will increase the survivability of near-Earth missions as well as missions to the Moon and Mars,” said Reggie Eason, SET project manager at NASA Headquarters in Washington.


SET aims its sights on a part of near-Earth space called the slot region: the gap between two of Earth’s vast radiation belts, also known as the Van Allen belts. The doughnut-shaped Van Allen belts seethe with radiation trapped by Earth’s magnetic field. Where SET orbits is thought to be calmer, but known to vary during extreme space weather storms driven by the Sun. How much it changes exactly, and how quickly, remains uncertain.


“There haven’t been too many measurements to tell us how bad things get in the slot region,” said Michael Xapsos. Xapsos is one of two members on the SET Project Scientist Team alongside astrophysicist Yihua Zheng at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That’s why we’re going there. Before we put satellites there, you have to be aware of how variable the environment is,” Xapsos said.



Getting SET — The Mission to Protect Satellites from Radiation

Video above: SET studies the very nature of space itself — which isn’t completely empty, but brimming with radiation — and how it affects spacecraft and electronics in orbit. Video Credits: NASA’s Goddard Space Flight Center/Genna Duberstein.


The slot region is an attractive one for satellites — especially navigation and communications satellites — because from about 12,000 miles up, it offers not only a relatively friendly radiation environment, but also a wide view of Earth. During intense magnetic storms, however, energetic particles from the outer belt can surge into the slot region. 


SET will survey the slot region, providing some of the first day-to-day weather measurements of this particular neighborhood in near-Earth space. The mission also studies the fine details of how radiation damages instruments and tests different methods to protect them, helping engineers build parts better suited for spaceflight.


“Electronic devices these days are so small, complicated and fast,” Xapsos said. The smaller a device is, the more vulnerable it is to radiation damage, and the more challenging it is to predict its performance in space. “SET will allow us to better understand what happens when an ion hits a device, and to improve models for how often these upsets occur.”


There are two kinds of radiation damage that SET studies. The first are known as single event effects — that is, what happens when a high-energy ion accelerated by a solar eruption or from a galactic cosmic ray pierces electronics. These strikes happen at random, one particle at a time, and load a circuit with extra electric charge. The result can be a data flip — in binary code, for example, flipping a 0 to a 1 — that affects stored memory or the programs that run spacecraft. Many spacecraft are equipped to recover from these snags, but at worst, they can cause system crashes and catastrophic damage.


But these dramatic blows aren’t the only concern — milder radiation over time degrades circuits too. Charged particles trapped in the radiation belts weather electronics, gradually reducing their performance the longer they’re in orbit.



Animation above: Earth’s radiation belts are filled with energetic particles trapped by Earth’s magnetic field that can wreak havoc with electronics we send to space.
Animation Credits: NASA’s Scientific Visualization Studio/Tom Bridgman.


SET is equipped with a space weather monitor and three circuit board experiments — each no larger than a postcard — to study both types of damage.


CREDANCE — short for the Cosmic Radiation Environment Dosimetry and Charging Experiment — is SET’s space weather monitor, built to survey cosmic rays and particles in the radiation belts. These are the high-energy fragments of atoms that can pierce the walls of spacecraft, damaging electronics.


Two circuit board experiments also study single event effects. COTS-2 — standing for Commercial Off the Shelf — collects information on the frequency of single event effects and how to mitigate them, especially in specialized computer chips. DIME — short for the Dosimetry Intercomparison and Miniaturization Experiment — consists of two separate boards that together demonstrate six different ways to measure space radiation using affordable, commercially available parts. The experiment can help future missions decide the best way to monitor radiation for their spacecraft.


Another circuit board experiment focuses on total radiation dose. ELDRS — short for Enhanced Low Dose Rate Sensitivity — is named for the mystery it studies: the ELDRS effect. This is what engineers call the intensified damage that certain types of electronics face when exposed to mild radiation over time — as opposed to the lesser damage experienced if exposed to the same total dose all at once. Information from this experiment will help improve test methods on Earth to make electronics space-ready.


Together, the SET experiments will expand our understanding of the near-Earth space environment and how its radiation impacts instruments. “SET data will directly go into improving our models so we can better evaluate the radiation environment future missions will encounter,” said Goddard aerospace engineer Megan Casey. Models are a key component in selecting and testing any electronics destined for spaceflight.


SET is part of the Space Environment Effects (SFx) experiment, one of three experiments on board the Demonstration and Science Experiments, or DSX, spacecraft being launched by the U.S. Air Force.


DSX is launching as part of the Space Test Program-2 (STP-2) mission, managed by the U.S. Air Force Space and Missile Systems Center (SMC). SET is one of four NASA missions on this STP-2 launch — all of which are dedicated to improving technology in space. DSX separates from the launch vehicle approximately 3.5 hours after launch.


SET is the latest addition to NASA’s fleet of heliophysics observatories. NASA heliophysics missions study a vast interconnected system from the Sun to the space surrounding Earth and other planets, and to the farthest limits of the Sun’s constantly flowing stream of solar wind. SET’s observations provide key information on the Sun’s effects on our spacecraft, enabling further exploration of space.


SET is part of NASA’s Living with a Star program, which explores aspects of the Sun-Earth system that directly affect human life and society. The Living with a Star flight program is managed by Goddard.


NASA launch coverage begins approximately 25 minutes before launch. Follow launch coverage on NASA Television at: https://www.nasa.gov/live


SET (Space Environment Testbeds): http://nasa.gov/set


Artemis program: https://www.nasa.gov/artemis


Image (mentioned), Animation (mentioned), Video (mentioned), Text, Credits: NASA’s Goddard Space Flight Center, by Lina Tran.


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Health Checkups, Station Gardening and Space Science Fill Tuesday


ISS — Expedition 59 Mission patch.


June 11, 2019


Four Expedition 59 astronauts underwent periodic health checkups and regularly scheduled eye scans today. The International Space Station residents also had time set aside for space gardening, furnace work, crew ship packing and radiation checks.


Astronauts Anne McClain and Christina Koch started Tuesday morning checking each other’s vital signs including temperature, blood pressure, pulse and respiratory rate. They were followed shortly afterward by Flight Engineers Nick Hague and David Saint-Jacques.



Image above: (From bottom to top) The Northrop Grumman Cygnus space freighter, the Soyuz MS-12 crew ship and the Progress 72 cargo craft are pictured attached to the International Space Station as the orbiting complex flew 258 miles above the Gulf of St. Lawrence. Image Credit: NASA.


In the afternoon, the Koch and Hague swapped roles as Crew Medical Officer (CMO) and used an ultrasound device to scan each other’s eyes. Saint-Jacques then took over as CMO and activated the optical coherence tomography gear to image the retinas of Koch and Hague. The ongoing eye exams help flight surgeons understand how long-term weightlessness affects vision and the shape of the eye.


McClain and Koch spent a few moments in the middle of their eye checks today thinning and watering plants for the Veg-04 botany experiment. The research takes place in a specialized greenhouse and explores the feasibility of a continuous fresh food production system in Europe’s Columbus laboratory module.



International Space Station (ISS). Image Credit: NASA

After the vital sign checks, Hague partnered up with McClain to reconfigure and install an advanced furnace in the Japanese Kibo laboratory module. The Electrostatic Levitation Furnace enables the observation of thermophysical properties and the synthesis of high temperature materials on the station.


Commander Oleg Kononenko continued readying the Soyuz MS-11 crew ship for its departure June 24 carrying him, McClain and Saint-Jacques back to Earth. Flight Engineer Alexey Ovchinin collected radiation sensors from the station’s U.S. side and downloaded measurement readings. The Russian duo also trained to operate a unique suit that counteracts microgravity and draws body fluids towards the feet to minimize head pressure.


Related links:


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


Veg-04 botany experiment: https://go.nasa.gov/2Kpic4W


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


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


Electrostatic Levitation Furnace: https://www.nasa.gov/mission_pages/station/research/experiments/explorer/Facility.html?#id=1536


Unique suit: https://blogs.nasa.gov/ISS_Science_Blog/2015/06/02/rubber-vacuum-pants-that-suck/


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


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


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Magnetic Field May Be Keeping Milky Way’s Black Hole Quiet


NASA & DLR — SOFIA Mission patch.


June 11, 2019


Supermassive black holes exist at the center of most galaxies, and our Milky Way is no exception. But many other galaxies have highly active black holes, meaning a lot of material is falling into them, emitting high-energy radiation in this “feeding” process. The Milky Way’s central black hole, on the other hand, is relatively quiet. New observations from NASA’s Stratospheric Observatory for Infrared Astronomy, SOFIA, are helping scientists understand the differences between active and quiet black holes.


These results give unprecedented information about the strong magnetic field at the center of the Milky Way galaxy. Scientists used SOFIA’s newest instrument, the High-resolution Airborne Wideband Camera-Plus, HAWC+, to make these measurements.



Image above: Streamlines showing magnetic fields layered over a color image of the dusty ring around the Milky Way’s massive black hole. The Y-shaped structure is warm material falling toward the black hole, which is located near where the two arms of the Y-shape intersect. The streamlines reveal that the magnetic field closely follows the shape of the dusty structure. Each of the blue arms has its own field that is totally distinct from the rest of the ring, shown in pink. Image Credits: Dust and magnetic fields: NASA/SOFIA; Star field image: NASA/Hubble Space Telescope.


Magnetic fields are invisible forces that influence the paths of charged particles, and have significant effects on the motions and evolution of matter throughout the universe. But magnetic fields cannot be imaged directly, so their role is not well understood. The HAWC+ instrument detects polarized far-infrared light, which is invisible to human eyes, emitted by celestial dust grains. These grains align perpendicular to magnetic fields. From the SOFIA results, astronomers can map the shape and infer the strength of the otherwise invisible magnetic field, helping to visualize this fundamental force of nature.


“This is one of the first instances where we can really see how magnetic fields and interstellar matter interact with each other,” noted Joan Schmelz, Universities Space Research Center astrophysicist at NASA Ames Research Center in California’s Silicon Valley, and a co-author on a paper describing the observations.  “HAWC+ is a game-changer.”


Previous observations from SOFIA show the tilted ring of gas and dust orbiting the Milky Way’s black hole, which is called Sagittarius A* (pronounced “Sagittarius A-star”). But the new HAWC+ data provide a unique view of the magnetic field in this area, which appears to trace the region’s history over the past 100,000 years.


Details of these SOFIA magnetic field observations were presented at the June 2019 meeting of the American Astronomical Society and will be submitted to the Astrophysical Journal.


The gravity of the black hole dominates the dynamics of the center of the Milky Way, but the role of the magnetic field has been a mystery. The new observations with HAWC+ reveal that the magnetic field is strong enough to constrain the turbulent motions of gas. If the magnetic field channels the gas so it flows into the black hole itself, the black hole is active, because it is eating a lot of gas. However, if the magnetic field channels the gas so it flows into an orbit around the black hole, then the black hole is quiet because it’s not ingesting any gas that would otherwise eventually form new stars.


Researchers combined mid- and far-infrared images from SOFIA’s cameras with new streamlines that visualize the direction of the magnetic field. The blue y-shaped structure (see figure) is warm material falling toward the black hole, which is located near where the two arms of the y-shape intersect. Layering the structure of the magnetic field over the image reveals that the magnetic field follows the shape of the dusty structure. Each of the blue arms has its own field component that is totally distinct from the rest of the ring, shown in pink. But there are also places where the field veers away from the main dust structures, such as the top and bottom endpoints of the ring.


“The spiral shape of the magnetic field channels the gas into an orbit around the black hole,” said Darren Dowell, a scientist at NASA’s Jet Propulsion Laboratory, principal investigator for the HAWC+ instrument, and lead author of the study. “This could explain why our black hole is quiet while others are active.”



Stratospheric Observatory for Infrared Astronomy (SOFIA). Animation Credit: NASA

The new SOFIA and HAWC+ observations help determine how material in the extreme environment of a supermassive black hole interacts with it, including addressing a longstanding question of why the central black hole in the Milky Way is relatively faint while those in other galaxies are so bright.


SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP jetliner modified to carry a 106-inch diameter telescope. It is a joint project of NASA and the German Aerospace Center, DLR. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute (DSI) at the University of Stuttgart. The aircraft is maintained and operated from NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California. The HAWC+ instrument was developed and delivered to NASA by a multi-institution team led by the Jet Propulsion Laboratory in Pasadena, California.


Related links:


SOFIA: http://www.nasa.gov/mission_pages/SOFIA/index.html


Black Holes: https://www.nasa.gov/black-holes


Image (mentioned), Animation (mentioned), Text, Credits: NASA/Kassandra Bell/Elizabeth Landau/JPL/Calla Cofield/SOFIA Science Center/Nicholas Veronico.


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Caption Spotlight (11 June 2019): Rhythmic Layers East of…


Caption Spotlight (11 June 2019): Rhythmic Layers East of Medusae Fossae


The surface of this image looks wavy, like that of the sea. These wave shapes are the result of erosion: the removal of material, which has been ongoing for millions, if not billions, of years. This erosion is likely performed by the action of wind and has revealed layered rock that was deposited in this area in the ancient past.


The layers were deposited very regularly one on top of another and the erosion has cut across them—sometimes shallowly, sometimes more deeply—to create these giant undulations. More resistant layers protrude further, making them the visible crests of the waves.


NASA/JPL/University of Arizona


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