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  • richardmitnick 3:46 pm on October 15, 2021 Permalink | Reply
    Tags: "Two Impacts-Not Just One-May Have Formed The Moon", , , , Planetary Science,   

    From Sky & Telescope : “Two Impacts-Not Just One-May Have Formed The Moon” 

    From Sky & Telescope

    October 14, 2021
    Asa Stahl

    In this image, the proposed hit-and-run collision is simulated in 3D, shown about an hour after impact. Theia, the impactor, barely escapes the collision. A. Emsenhuber / The University of Bern [Universität Bern](CH) / The Ludwig Maximilians University of Munich [Ludwig-Maximilians-Universität München](DE).

    Scientists have long thought that the Moon formed with a bang, when a protoplanet the size of Mars hit the newborn Earth. Evidence from Moon rocks and simulations back up this idea.

    But a new study suggests that the protoplanet most likely hit Earth twice. The first time, the impactor (dubbed “Theia”) only glanced off Earth. Then, some hundreds of thousands of years later, it came back to deliver the final blow.

    The study, which simulated the literally Earth-shattering impact thousands of times, found that such a “hit-and-run return” scenario could help answer two longstanding questions surrounding the creation of the Moon. At the same time, it might explain how Earth and Venus ended up so different.

    The One-Two Punch

    “The key issue here is planetary diversity,” says Erik Asphaug (The University of Arizona (US)), who led the study. Venus and Earth have similar sizes, masses, and distances from the Sun. If Venus is a “crushing hot-house,” he asks, “why is Earth so amazingly blue and rich?”

    The Moon might hold the secret. Its creation was the last major episode in Earth’s formation, a catastrophic event that set the stage for the rest of our planet’s evolution. “You can’t understand how Earth formed without understanding how the Moon formed,” Asphaug explains. “They are part of the same puzzle.”

    The new simulations, which were published in the October Journal of Planetary Sciences, put a few more pieces of that puzzle into place.

    The first has to do with the speed of Theia’s impact. If Theia had hit our planet too fast, it would have exploded into an interplanetary plume of debris and eroded much of Earth. Yet if it had come in too slowly, the result would be a Moon whose orbit looks nothing like what we see today. The original impact theory doesn’t explain why Theia traveled at a just-right speed between these extremes.

    “[This] new scenario fixes that,” says Matthias Meier (Natural History Museum, Switzerland), who was not involved in the study. Initially, Theia could have been going much faster, but the first impact would have slowed it down to the perfect speed for the second one.

    The other problem with the original impact theory is that our Moon ought to be mostly made of primordial Theia. But Moon rocks from the Apollo missions show that Earth and the Moon have nearly identical compositions when it comes to certain kinds of elements. How could they have formed from two different building blocks?

    “The canonical giant-impact scenario is really bad at solving [this issue],” Meier says (though others have tried).

    A hit-and-run return, on the other hand, would enable Earth’s and Theia’s materials to mix more than in a single impact, ultimately forming a Moon chemically more similar to Earth. Though Asphaug and colleagues don’t quite fix the mismatch, they argue that more advanced simulations would yield even better results.

    Earth vs. Venus

    Resolving this aspect of the giant-impact theory would be no mean feat. But Asphaug’s real surprise came when he saw how hit-and-run impacts would have affected Venus compared to Earth.

    “I first thought maybe there was a mistake,” he recalls.

    The new simulations showed that the young Earth tended to pass on half of its hit-and-runners to Venus, while Venus accreted almost everything that came its way. This dynamic could help explain the drastic differences between the two planets: If more runners ended up at Venus, they would have enriched the planet in more outer solar system material compared to Earth. And since the impactors that escaped Earth to go on to Venus would have been the faster ones, each planet would have experienced generally different collisions.

    This finding flips the original purpose of the study on its head. If Venus suffered more giant impacts than Earth, the question would no longer be “why does Earth have a moon?” but “why doesn’t Venus?”

    Perhaps there was only one hit-and-run event, the one that made our Moon. Perhaps there were many, but for the same reason that Venus collected more impacts than Earth, it also accreted more destructive debris, obliterating any moon it already had. Or perhaps the last of Venus’ impacts was just particularly violent.

    Finding out means taking a trip to Venus. That would provide “the next leap in understanding,” Meier says. If Earth and Venus both had hit-and-runs, for example, then the surface of Venus ought to be more like Earth’s than previously expected. If Venus has the same chemical similarities as the Moon and Earth, that would throw out the giant-impact theory’s last remaining problem.

    “Getting samples from Venus,” Asphaug concludes, “is the key to answering all these questions.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Sky & Telescope, founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, has the largest, most experienced staff of any astronomy magazine in the world. Its editors are virtually all amateur or professional astronomers, and every one has built a telescope, written a book, done original research, developed a new product, or otherwise distinguished him or herself.

    Sky & Telescope magazine, now in its eighth decade, came about because of some happy accidents. Its earliest known ancestor was a four-page bulletin called The Amateur Astronomer, which was begun in 1929 by the Amateur Astronomers Association in New York City. Then, in 1935, the American Museum of Natural History opened its Hayden Planetarium and began to issue a monthly bulletin that became a full-size magazine called The Sky within a year. Under the editorship of Hans Christian Adamson, The Sky featured large illustrations and articles from astronomers all over the globe. It immediately absorbed The Amateur Astronomer.

    Despite initial success, by 1939 the planetarium found itself unable to continue financial support of The Sky. Charles A. Federer, who would become the dominant force behind Sky & Telescope, was then working as a lecturer at the planetarium. He was asked to take over publishing The Sky. Federer agreed and started an independent publishing corporation in New York.

    “Our first issue came out in January 1940,” he noted. “We dropped from 32 to 24 pages, used cheaper quality paper…but editorially we further defined the departments and tried to squeeze as much information as possible between the covers.” Federer was The Sky’s editor, and his wife, Helen, served as managing editor. In that January 1940 issue, they stated their goal: “We shall try to make the magazine meet the needs of amateur astronomy, so that amateur astronomers will come to regard it as essential to their pursuit, and professionals to consider it a worthwhile medium in which to bring their work before the public.”

  • richardmitnick 8:20 pm on October 14, 2021 Permalink | Reply
    Tags: "How do ice giants maintain their magnetic fields?", , Planetary Science   

    From Carnegie Institution for Science (US) : “How do ice giants maintain their magnetic fields?” 

    Carnegie Institution for Science

    From Carnegie Institution for Science (US)

    A layer of “hot,” electrically conductive ice could be responsible for generating the magnetic fields of ice giant planets like Uranus and Neptune. New work from Carnegie and The University of Chicago (US)’s Center for Advanced Radiation Sources reveals the conditions under which two such superionic ices form. Their findings are published in Nature Physics.


    As all school children learn, water molecules are made up of two hydrogen atoms and one oxygen atom—H20. As the conditions in which water exists change, the organization and properties of these molecules are affected. We can see this in our everyday lives when liquid water is boiled into steam or frozen into ice.

    The molecules that comprise ordinary ice that you might find in your drinking glass or on your driveway in winter arranged in a crystalline lattice held together by hydrogen bonds between the hydrogen and oxygen atoms. Hydrogen bonds are highly versatile. This means that ice can exist in a striking diversity of different structures—at least 18 known forms—which emerge under increasingly extreme environmental conditions.

    Of particular interest is so-called superionic ice, formed at very high pressures and temperatures, in which the traditional water molecule bonds are shifted, allowing the hydrogen molecules to float freely in an oxygen lattice. This mobility makes the ice capable of conducting electricity almost as well as a metallic material.

    Observations of hot, superionic ice created in the lab have led to contradictory results and there has been a great deal of disagreement about the exact conditions under which the new properties emerge.

    “So, our research team, led by the University of Chicago’s Vitali Prakapenka, set out to use multiple spectroscopic tools to map changes in ice’s structure and properties under conditions ranging up to 1.5 million times normal atmospheric pressure and about 11,200 degrees Fahrenheit,” explained Carnegie’s Alexander Goncharov.

    Figure illustrating how the experiments were performed, revealing two forms of superionic ice, courtesy of Vitali Prakapenka.

    By doing this, the scientists—also including Nicholas Holtgrewe formerly of Carnegie, now at The Food and Drug Administration (US) in St Louis, and Sergey Lobanov, formerly of Carnegie, now at the GFZ German Research Centre for Geosciences (GFZ) [Deutsches Forschungszentrum für Geowissenschaften] (DE)—were able to pinpoint the emergence of two forms of superionic ice, one of which they suggest could be found in the interiors of ice giant planets Uranus and Neptune.

    “In order to probe the structure of this unique state of matter under very extreme conditions—heated by a laser and compressed between two diamonds—we used the ANL Advanced Photon Source (US)’s brilliant high-energy synchrotron x-ray beam, which was focused down to about 3 micrometers, 30 times smaller than a single human hair,” said Prakapenka, explaining the work done using the facility’s GSECARS beamline.

    “These experiments are so challenging that we had to run a few thousand of them over a decade to get enough high-quality data to solve the long-standing mystery of high-pressure, high-temperature behavior of ice under conditions relevant to giant planet interiors.”

    “Simulations have indicated that the magnetic fields of these two planets are generated in thin, fluid layers found at relatively shallow depths,” Goncharov added. “The conductivity of superionic ice would be able to accomplish this type of field generation and one of the two structures we revealed could exist under the conditions found in these magnetic field-generating zones.”

    Further study is needed to understand the conductive properties and viscosity of these ice phases under ice giant-interior conditions.


    This work was supported by the U.S. National Science Foundation, the Army Research Office, the Deep Carbon Observatory, the Helmholtz Young Investigators Group, and the Carnegie Institution for Science. This work was performed at GeoSoilEnviroCARS, Advanced Photon Source, Argonne National Laboratory.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Carnegie Institution of Washington Bldg

    Carnegie Institution for Science (US)

    Andrew Carnegie established a unique organization dedicated to scientific discovery “to encourage in the broadest and most liberal manner investigation; research; and discovery and the application of knowledge to the improvement of mankind…” The philosophy was and is to devote the institution’s resources to “exceptional” individuals so that they can explore the most intriguing scientific questions in an atmosphere of complete freedom. Carnegie and his trustees realized that flexibility and freedom were essential to the institution’s success and that tradition is the foundation of the institution today as it supports research in the Earth, space, and life sciences.

    The Carnegie Institution of Washington (US) (the organization’s legal name), known also for public purposes as the Carnegie Institution for Science (US) (CIS), is an organization in the United States established to fund and perform scientific research. The institution is headquartered in Washington, D.C. As of June 30, 2020, the Institution’s endowment was valued at $926.9 million. In 2018 the expenses for scientific programs and administration were $96.6 million.


    When the United States joined World War II Vannevar Bush was president of the Carnegie Institution. Several months before on June 12, 1940 Bush had been instrumental in persuading President Franklin Roosevelt to create the National Defense Research Committee (later superseded by the Office of Scientific Research and Development) to mobilize and coordinate the nation’s scientific war effort. Bush housed the new agency in the Carnegie Institution’s administrative headquarters at 16th and P Streets, NW, in Washington, DC, converting its rotunda and auditorium into office cubicles. From this location Bush supervised, among many other projects the Manhattan Project. Carnegie scientists cooperated with the development of the proximity fuze and mass production of penicillin.


    Carnegie scientists continue to be involved with scientific discovery. Composed of six scientific departments on the East and West Coasts the Carnegie Institution for Science is involved presently with six main topics: Astronomy at the Department of Terrestrial Magnetism (Washington, D.C.) and the Observatories of the Carnegie Institution of Washington (Pasadena, CA and Las Campanas, Chile); Earth and planetary science also at the Department of Terrestrial Magnetism and the Geophysical Laboratory (Washington, D.C.); Global Ecology at the Department of Global Ecology (Stanford, CA); Genetics and developmental biology at the Department of Embryology (Baltimore, MD); Matter at extreme states also at the Geophysical Laboratory; and Plant science at the Department of Plant Biology (Stanford, CA).

    Carnegie Institution 1-meter Swope telescope at Las Campanas, Chile, 100 kilometres (62 mi) northeast of the city of La Serena, near the north end of a 7 km (4.3 mi) long mountain ridge, Cerro Las Campanas, near the southern end and over 2,500 m (8,200 ft) high, at Las Campanas, Chile.

  • richardmitnick 12:06 pm on September 27, 2021 Permalink | Reply
    Tags: "Hubble Shows Winds in Jupiter's Great Red Spot Are Speeding Up", , Planetary Science   

    From NASA’s Goddard Space Flight Center (US) : “Hubble Shows Winds in Jupiter’s Great Red Spot Are Speeding Up” 

    NASA Goddard Banner

    From NASA’s Goddard Space Flight Center (US)

    Sep 27, 2021

    Claire Andreoli
    NASA’s Goddard Space Flight Center

    Claire Blome/
    Space Telescope Science Institute, Baltimore, Maryland

    Ray Villard
    Space Telescope Science Institute, Baltimore, Maryland


    Michael H. Wong
    The University of California-Berkeley

    Amy Simon
    NASA’s Goddard Space Flight Center, Greenbelt, Maryland

    Like the speed of an advancing race car driver, the winds in the outermost “lane” of Jupiter’s Great Red Spot are accelerating – a discovery only made possible by NASA’s Hubble Space Telescope, which has monitored the planet for more than a decade.

    Researchers analyzing Hubble’s regular “storm reports” found that the average wind speed just within the boundaries of the storm, known as a high-speed ring, has increased by up to 8 percent from 2009 to 2020. In contrast, the winds near the red spot’s innermost region are moving significantly more slowly, like someone cruising lazily on a sunny Sunday afternoon.

    By analyzing images taken by NASA’s Hubble Space Telescope from 2009 to 2020, researchers found that the average wind speed just within the boundaries of the Great Red Spot, set off by the outer green circle, have increased by up to 8 percent from 2009 to 2020 and exceed 400 miles per hour. In contrast, the winds near the storm’s innermost region, set off by a smaller green ring, are moving significantly more slowly. Both move counterclockwise. Credits: NASA, ESA, Michael H. Wong (UC Berkeley).

    The massive storm’s crimson-colored clouds spin counterclockwise at speeds that exceed 400 miles per hour – and the vortex is bigger than Earth itself. The red spot is legendary in part because humans have observed it for more than 150 years.

    “When I initially saw the results, I asked ‘Does this make sense?’ No one has ever seen this before,” said Michael Wong of the University of California, Berkeley, who led the analysis
    published today in Geophysical Research Letters. “But this is something only Hubble can do. Hubble’s longevity and ongoing observations make this revelation possible.”

    We use Earth-orbiting satellites and airplanes to track major storms on Earth closely in real time. “Since we don’t have a storm chaser plane at Jupiter, we can’t continuously measure the winds on site,” explained Amy Simon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who contributed to the research. “Hubble is the only telescope that has the kind of temporal coverage and spatial resolution that can capture Jupiter’s winds in this detail.”

    The change in wind speeds they have measured with Hubble amount to less than 1.6 miles per hour per Earth year. “We’re talking about such a small change that if you didn’t have eleven years of Hubble data, we wouldn’t know it happened,” said Simon. “With Hubble we have the precision we need to spot a trend.” Hubble’s ongoing monitoring allows researchers to revisit and analyze its data very precisely as they keep adding to it. The smallest features Hubble can reveal in the storm are a mere 105 miles across, about twice the length of the state of Rhode Island.

    “We find that the average wind speed in the Great Red Spot has been slightly increasing over the past decade,” Wong added. “We have one example where our analysis of the two-dimensional wind map found abrupt changes in 2017 when there was a major convective storm nearby.”

    Hubble Observes Jupiter’s Great Red Spot Changing.
    Like the speed of an advancing race car driver, the winds in the outermost “lane” of Jupiter’s Great Red Spot are accelerating – a discovery only made possible by NASA’s Hubble Space Telescope, which has monitored the planet for more than a decade. Researchers analyzing Hubble’s regular “storm reports” found that the average wind speed just within the boundaries of the storm, known as a high-speed ring, has increased by up to 8% from 2009 to 2020. In contrast, the winds near the red spot’s innermost region are moving significantly more slowly, like someone cruising lazily on a sunny Sunday afternoon.
    Credits: NASA’s Goddard Space Flight Center/Paul Morris – Lead Producer

    To better analyze Hubble’s bounty of data, Wong took a new approach to his data analysis. He used software to track tens to hundreds of thousands of wind vectors (directions and speeds) each time Jupiter was observed by Hubble. “It gave me a much more consistent set of velocity measurements,” Wong explained. “I also ran a battery of statistical tests to confirm if it was justified to call this an increase in wind speed. It is.”

    What does the increase in speed mean? “That’s hard to diagnose, since Hubble can’t see the bottom of the storm very well. Anything below the cloud tops is invisible in the data,” explained Wong. “But it’s an interesting piece of data that can help us understand what’s fueling the Great Red Spot and how it’s maintaining energy.” There’s still a lot of work to do to fully understand it.

    Astronomers have pursued ongoing studies of the “king” of solar system storms since the 1870s. The Great Red Spot is an upwelling of material from Jupiter’s interior. If seen from the side, the storm would have a tiered wedding cake structure with high clouds at the center cascading down to its outer layers. Astronomers have noted that it is shrinking in size and becoming more circular than oval in observations spanning more than a century. The current diameter is 10,000 miles across, meaning that Earth could still fit inside it.

    In addition to observing this legendary, long-lived storm, researchers have observed storms on other planets, including Neptune, where they tend to travel across the planet’s surface and disappear over only a few years. Research like this helps scientists not only learn about the individual planets, but also draw conclusions about the underlying physics that drive and maintain planets’ storms.

    The majority of the data to support this research came from Hubble’s Outer Planets Atmospheres Legacy program, which provides annual Hubble global views of the outer planets that allow astronomers to look for changes in the planets’ storms, winds, and clouds.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    NASA/Goddard Campus

    NASA’s Goddard Space Flight Center, Greenbelt, MD (US) is home to the nation’s largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

    Named for American rocketry pioneer Dr. Robert H. Goddard, the center was established in 1959 as NASA’s first space flight complex. Goddard and its several facilities are critical in carrying out NASA’s missions of space exploration and scientific discovery.

    GSFC also operates two spaceflight tracking and data acquisition networks (the NASA Deep Space Network(US) and the Near Earth Network); develops and maintains advanced space and Earth science data information systems, and develops satellite systems for the National Oceanic and Atmospheric Administration(US) .

    GSFC manages operations for many NASA and international missions including the NASA/ESA Hubble Space Telescope; the Explorers Program; the Discovery Program; the Earth Observing System; INTEGRAL; MAVEN; OSIRIS-REx; the Solar and Heliospheric Observatory ; the Solar Dynamics Observatory; Tracking and Data Relay Satellite System ; Fermi; and Swift. Past missions managed by GSFC include the Rossi X-ray Timing Explorer (RXTE), Compton Gamma Ray Observatory, SMM, COBE, IUE, and ROSAT. Typically, unmanned Earth observation missions and observatories in Earth orbit are managed by GSFC, while unmanned planetary missions are managed by the Jet Propulsion Laboratory (JPL) in Pasadena, California(US).

    Goddard is one of four centers built by NASA since its founding on July 29, 1958. It is NASA’s first, and oldest, space center. Its original charter was to perform five major functions on behalf of NASA: technology development and fabrication; planning; scientific research; technical operations; and project management. The center is organized into several directorates, each charged with one of these key functions.

    Until May 1, 1959, NASA’s presence in Greenbelt, MD was known as the Beltsville Space Center. It was then renamed the Goddard Space Flight Center (GSFC), after Robert H. Goddard. Its first 157 employees transferred from the United States Navy’s Project Vanguard missile program, but continued their work at the Naval Research Laboratory in Washington, D.C., while the center was under construction.

    Goddard Space Flight Center contributed to Project Mercury, America’s first manned space flight program. The Center assumed a lead role for the project in its early days and managed the first 250 employees involved in the effort, who were stationed at Langley Research Center in Hampton, Virginia. However, the size and scope of Project Mercury soon prompted NASA to build a new Manned Spacecraft Center, now the Johnson Space Center, in Houston, Texas. Project Mercury’s personnel and activities were transferred there in 1961.

    The Goddard network tracked many early manned and unmanned spacecraft.

    Goddard Space Flight Center remained involved in the manned space flight program, providing computer support and radar tracking of flights through a worldwide network of ground stations called the Spacecraft Tracking and Data Acquisition Network (STDN). However, the Center focused primarily on designing unmanned satellites and spacecraft for scientific research missions. Goddard pioneered several fields of spacecraft development, including modular spacecraft design, which reduced costs and made it possible to repair satellites in orbit. Goddard’s Solar Max satellite, launched in 1980, was repaired by astronauts on the Space Shuttle Challenger in 1984. The Hubble Space Telescope, launched in 1990, remains in service and continues to grow in capability thanks to its modular design and multiple servicing missions by the Space Shuttle.

    Today, the center remains involved in each of NASA’s key programs. Goddard has developed more instruments for planetary exploration than any other organization, among them scientific instruments sent to every planet in the Solar System. The center’s contribution to the Earth Science Enterprise includes several spacecraft in the Earth Observing System fleet as well as EOSDIS, a science data collection, processing, and distribution system. For the manned space flight program, Goddard develops tools for use by astronauts during extra-vehicular activity, and operates the Lunar Reconnaissance Orbiter, a spacecraft designed to study the Moon in preparation for future manned exploration.

  • richardmitnick 8:39 am on September 15, 2021 Permalink | Reply
    Tags: "Impact on Jupiter surprises skywatchers", , Planetary Science   

    From EarthSky : “Impact on Jupiter surprises skywatchers” 


    From EarthSky

    September 14, 2021
    Kelly Kizer Whitt

    Harald Paleske in Langendorf, Germany, captured this image of a bright flash of light as something impacted Jupiter on September 13, 2021. Io and its shadow are on the left side of Jupiter, while the flash is to the right of center. Image via https://spaceweathergallery.com .

    Photographers capture an impact on Jupiter

    Observers around the globe were surprised on September 13, 2021, when they witnessed an apparent impact on the giant planet Jupiter. A bright flash of light distracted them from their observing target: an ongoing transit of the shadow of the Jovian moon Io across the face of Jupiter. A couple of lucky astrophotographers managed to snap images of the flash.

    The image at top comes from Germany. Harald Paleske told SpaceWeather.com he was watching the dark shadow of Io cross onto Jupiter’s surface when the burst of light startled him. He said:

    “A bright flash of light surprised me. It could only be an impact.”

    Paleske had been taking a video of the transit of Io’s shadow when the event occurred. He looked over his video frames, searching for a satellite or plane that might have shown up as the bright patch. But he found no evidence that the event happened close to Earth or that’s he’d witnessed an earthly event with Jupiter as mere backdrop. He timed the event as happening at 22:39:27 UTC on September 13 and lasting for two seconds.

    Another astronomer, José Luis Pereira of Brazil, also captured the flash from the impact. ESA Operations tweeted his photo via Flickr.

    Light on at Jupiter! Anyone home? This bright impact flash was spotted yesterday on the giant planet by astronomer José Luis Pereira.

    Not a lot of info on the impacting object yet but its likely to be large and/or fast!

    Thanks Jupiter for taking the hit??#PlanetaryDefence pic.twitter.com/XLFzXjW4KQ2

    — ESA Operations (@esaoperations) September 14, 2021

    A French astrophotographer, J.P. Arnould, also captured the surprising event.

    Impact Flash on Jupiter confirmed by at least 2 amateur astronomers: H. Paleske in Germany & by J.P. Arnould in France. See attached images & for more info about past Jupiter impact events: https://t.co/VIpSt2TQfn #astronomy #jupiter #impact pic.twitter.com/0kMP7iRMao

    — Ernesto Guido (@comets77) September 14, 2021

    What hit Jupiter?

    It’s too soon to know, but a comet or asteroid would be the most likely culprit. As Spaceweather.com said:

    An asteroid in the 100-meter size range (about 300 feet) would do the trick.

    Skywatchers with telescopes from all parts of Earth are poised to view Jupiter following the impact. They’re hoping to spot a dark mark or temporary scar resulting from the impact. That’s what happened during the best-known impacts on Jupiter, which happened in July of 1994. Comet Shoemaker-Levy 9 blazed a path directly toward Jupiter. Professional observatories were ready to catch the resulting collision. Shoemaker-Levy 9 left an entire trail of debris across the gas giant planet, as Jupiter’s intense tidal forces tore it to pieces.

    Brown spots mark the places where fragments of Comet Shoemaker-Levy 9 tore through Jupiter’s atmosphere in July 1994. Image via Wikimedia Commons.

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

  • richardmitnick 10:02 am on September 11, 2021 Permalink | Reply
    Tags: "Cassini’s wake-how might a spacecraft disturb its own measurements?", , , , Planetary Science   

    From European Space Agency [Agence spatiale européenne] [Europäische Weltraumorganisation](EU) : “Cassini’s wake-how might a spacecraft disturb its own measurements?” 

    ESA Space For Europe Banner

    European Space Agency – United Space in Europe (EU)

    From European Space Agency [Agence spatiale européenne] [Europäische Weltraumorganisation](EU)


    Illustration of Cassini diving towards Saturn as part of the mission’s Grand Finale.
    The spacecraft will burn up in Saturn’s atmosphere on 15 September 2017, satisfying planetary protection requirements to avoid possible contamination of any moons of Saturn that could have conditions suitable for life. Credit: NASA/JPL-Caltech (US).

    Simply by moving through the heavens, spacecraft change the space about them. Such interactions are invisible to the naked eye, but can endanger mission performance and safety. A new ESA Resarch Fellow study simulated the Cassini spacecraft in the vicinity of Saturn, checking the findings against actual space measurements. It reveals Cassini cast an ‘ion wake’ up to 6 m behind it, a void of plasma particles like a trail of a boat.

    Space might be a vacuum but it is far from empty, awash with charged particles and electromagnetic fields. This study, published in the Journal of Geophysical Research: Space Physics, employed ESA-funded software called the Spacecraft Plasma Interaction System (SPIS), used to model the interaction between spacecraft and these surrounding environments.

    “This study marks the first time that these simulations have been compared to and confirmed with actual spacecraft measurements from a planet beyond Earth,” explains ESA Research Fellow Mika Holmberg, who spent three years at ESA’s Space Environments and Effects section at the ESTEC technical centre in the Netherlands.

    Saturn bowshock.

    The international Cassini spacecraft exploring the magnetic environment of Saturn. The image is not to scale. Saturn’s magnetosphere is depicted in grey, while the complex bow shock region – the shock wave in the solar wind that surrounds the magnetosphere – is shown in blue.
    While crossing the bow shock on 3 February 2007, Cassini recorded a particularly strong shock (an Alfvén Mach number of approximately 100) under a ‘quasi-parallel’ magnetic field configuration, during which significant particle acceleration was detected for the first time. The findings provide insight into particle acceleration at the shocks surrounding the remnants of supernova explosions. Credit: ESA.

    The study focused on the NASA-ESA-ASI Cassini-Huygens spacecraft, which left Earth in 1997 for a nearly two-decade odyssey to explore Saturn and its major moons. The gas giant’s magnetic field is the second largest of any planet’s – populated by charged particles originating from both Saturn itself and its 82 moons.

    Mika comments: “Cassini’s suite of instruments included a Langmuir probe, an electrode extending out from the spacecraft body. Think of it as a ‘space weather station’, to measure the density, temperature and velocity of the charged particles surrounding the spacecraft. This instrument provided the solid data to confirm the accuracy of our SPIS simulation.”

    These kind of simulations are useful in principle for any spacecraft or instrumentation placed in space, but especially for scientific missions focused on studying the space environments of the planets, including Earth.

    Mika adds: “They are important for accurate analyses of particle and field measurements from planetary missions, including the direct characterisation of space environments such as magnetospheres, the solar wind, the ionospheres of planets and moons – even possible plumes arising from them. Cassini gave us an exciting example of the latter when it passed through a plume originating from the icy moon Enceladus, revealing evidence of liquid water beneath its frozen surface.

    “But, crucially, results from in-situ instruments may also be interpreted wrongly if local interactions are not properly accounted for, such as the wakes formed by the spacecraft.”

    SPIS is also commonly employed to model the occurence of surface charging across various spacecraft surfaces, which can give rise to ‘electrostatic discharge’ – essentially a kind of space lightning that risks severe damage to subsystems or may even threaten mission loss. This charging of the spacecraft is driven in turn by the particles and radiation surrounding it.

    Modelling the ion density around Cassini.

    Even sustained sunlight liberates electrons from spacecraft surfaces, a factor which needs accounting for within the modelling.

    Mika notes: “These insights are important for future planetary missions as well, such as NASA’s Europa Clipper and ESA’s Jupiter mission Juice.

    NASA/Europa Clipper annotated.

    NASA Europa Clipper depiction.

    European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU)JUICE Schematic.

    European Space Agency [Agence spatiale européenne](EU) Juice spacecraft depiction.

    We ran a large number of simulations for Juice which actually resulted in the changing of some surface materials, since the simulations showed the mission might be in danger with the original selection.”

    SPIS is an open source software initiated back in 2001 by ESA with the support of French space agency CNES in collaboration with the French aerospace laboratory ONERA and the Artenum company.

    “Having a chance to work at ESA with the experts who were actually involved in developing the software was a golden opportunity,” adds Mika.

    ESA space environment and effects specialist Fabricie Cipriani oversaw Mika’s work at ESTEC: “The complexity and sensitivity of scientific instruments for planetary explorations continue to grow. So simulation tools of this kind are essential both to identify potential issues during early development phases, and to ensure the accurate interpretation of results once an instrument is flying – if, as in Cassini’s case, the spacecraft’s interaction with its environment is significant.

    “And in addition to her work on Cassini, Mika also performed challenging modelling work to quantify surface charging levels of the Juice spacecraft during its exploration of Jupiter’s Galilean moons. We now have a full model that will be very useful for later assessment, then ‐ once at Jupiter ‐ actual mission data exploitation.”

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU), established in 1975, is an intergovernmental organization dedicated to the exploration of space, currently with 19 member states. Headquartered in Paris, ESA has a staff of more than 2,000. ESA’s space flight program includes human spaceflight, mainly through the participation in the International Space Station program, the launch and operations of unmanned exploration missions to other planets and the Moon, Earth observation, science, telecommunication as well as maintaining a major spaceport, the Guiana Space Centre at Kourou, French Guiana, and designing launch vehicles. ESA science missions are based at ESTEC (NL) in Noordwijk, Netherlands, Earth Observation missions at ESRIN in Frascati, Italy, ESA Mission Control (ESOC) is in Darmstadt, Germany, the European Astronaut Centre (EAC) that trains astronauts for future missions is situated in Cologne, Germany, and the European Space Astronomy Centre is located in Villanueva de la Cañada, Spain.

    ESA’s space flight programme includes human spaceflight (mainly through participation in the International Space Station program); the launch and operation of uncrewed exploration missions to other planets and the Moon; Earth observation, science and telecommunication; designing launch vehicles; and maintaining a major spaceport, the The Guiana Space Centre [Centre Spatial Guyanais; CSG also called Europe’s Spaceport) at Kourou, French Guiana. The main European launch vehicle Ariane 5 is operated through Arianespace with ESA sharing in the costs of launching and further developing this launch vehicle. The agency is also working with NASA to manufacture the Orion Spacecraft service module that will fly on the Space Launch System.

    The agency’s facilities are distributed among the following centres:

    ESA European Space Research and Technology Centre (ESTEC) (NL)in Noordwijk, Netherlands;
    ESA Centre for Earth Observation [ESRIN] (IT) in Frascati, Italy;
    ESA Mission Control ESA European Space Operations Center [ESOC](DE) is in Darmstadt, Germany;
    ESA -European Astronaut Centre [EAC] trains astronauts for future missions is situated in Cologne, Germany;
    European Centre for Space Applications and Telecommunications (ECSAT) (UK), a research institute created in 2009, is located in Harwell, England;
    ESA – European Space Astronomy Centre [ESAC] (ES) is located in Villanueva de la Cañada, Madrid, Spain.
    European Space Agency Science Programme is a long-term programme of space science and space exploration missions.


    After World War II, many European scientists left Western Europe in order to work with the United States. Although the 1950s boom made it possible for Western European countries to invest in research and specifically in space-related activities, Western European scientists realized solely national projects would not be able to compete with the two main superpowers. In 1958, only months after the Sputnik shock, Edoardo Amaldi (Italy) and Pierre Auger (France), two prominent members of the Western European scientific community, met to discuss the foundation of a common Western European space agency. The meeting was attended by scientific representatives from eight countries, including Harrie Massey (United Kingdom).

    The Western European nations decided to have two agencies: one concerned with developing a launch system, ELDO (European Launch Development Organization), and the other the precursor of the European Space Agency, ESRO (European Space Research Organisation). The latter was established on 20 March 1964 by an agreement signed on 14 June 1962. From 1968 to 1972, ESRO launched seven research satellites.

    ESA in its current form was founded with the ESA Convention in 1975, when ESRO was merged with ELDO. ESA had ten founding member states: Belgium, Denmark, France, West Germany, Italy, the Netherlands, Spain, Sweden, Switzerland, and the United Kingdom. These signed the ESA Convention in 1975 and deposited the instruments of ratification by 1980, when the convention came into force. During this interval the agency functioned in a de facto fashion. ESA launched its first major scientific mission in 1975, Cos-B, a space probe monitoring gamma-ray emissions in the universe, which was first worked on by ESRO.

    ESA50 Logo large

    Later activities

    ESA collaborated with National Aeronautics Space Agency on the International Ultraviolet Explorer (IUE), the world’s first high-orbit telescope, which was launched in 1978 and operated successfully for 18 years.

    ESA Infrared Space Observatory.

    A number of successful Earth-orbit projects followed, and in 1986 ESA began Giotto, its first deep-space mission, to study the comets Halley and Grigg–Skjellerup. Hipparcos, a star-mapping mission, was launched in 1989 and in the 1990s SOHO, Ulysses and the Hubble Space Telescope were all jointly carried out with NASA. Later scientific missions in cooperation with NASA include the Cassini–Huygens space probe, to which ESA contributed by building the Titan landing module Huygens.

    As the successor of ELDO, ESA has also constructed rockets for scientific and commercial payloads. Ariane 1, launched in 1979, carried mostly commercial payloads into orbit from 1984 onward. The next two versions of the Ariane rocket were intermediate stages in the development of a more advanced launch system, the Ariane 4, which operated between 1988 and 2003 and established ESA as the world leader in commercial space launches in the 1990s. Although the succeeding Ariane 5 experienced a failure on its first flight, it has since firmly established itself within the heavily competitive commercial space launch market with 82 successful launches until 2018. The successor launch vehicle of Ariane 5, the Ariane 6, is under development and is envisioned to enter service in the 2020s.

    The beginning of the new millennium saw ESA become, along with agencies like National Aeronautics Space Agency(US), Japan Aerospace Exploration Agency, Indian Space Research Organisation, the Canadian Space Agency(CA) and Roscosmos(RU), one of the major participants in scientific space research. Although ESA had relied on co-operation with NASA in previous decades, especially the 1990s, changed circumstances (such as tough legal restrictions on information sharing by the United States military) led to decisions to rely more on itself and on co-operation with Russia. A 2011 press issue thus stated:

    “Russia is ESA’s first partner in its efforts to ensure long-term access to space. There is a framework agreement between ESA and the government of the Russian Federation on cooperation and partnership in the exploration and use of outer space for peaceful purposes, and cooperation is already underway in two different areas of launcher activity that will bring benefits to both partners.”

    Notable ESA programmes include SMART-1, a probe testing cutting-edge space propulsion technology, the Mars Express and Venus Express missions, as well as the development of the Ariane 5 rocket and its role in the ISS partnership. ESA maintains its scientific and research projects mainly for astronomy-space missions such as Corot, launched on 27 December 2006, a milestone in the search for exoplanets.

    On 21 January 2019, ArianeGroup and Arianespace announced a one-year contract with ESA to study and prepare for a mission to mine the Moon for lunar regolith.


    The treaty establishing the European Space Agency reads:

    The purpose of the Agency shall be to provide for and to promote, for exclusively peaceful purposes, cooperation among European States in space research and technology and their space applications, with a view to their being used for scientific purposes and for operational space applications systems…

    ESA is responsible for setting a unified space and related industrial policy, recommending space objectives to the member states, and integrating national programs like satellite development, into the European program as much as possible.

    Jean-Jacques Dordain – ESA’s Director General (2003–2015) – outlined the European Space Agency’s mission in a 2003 interview:

    “Today space activities have pursued the benefit of citizens, and citizens are asking for a better quality of life on Earth. They want greater security and economic wealth, but they also want to pursue their dreams, to increase their knowledge, and they want younger people to be attracted to the pursuit of science and technology. I think that space can do all of this: it can produce a higher quality of life, better security, more economic wealth, and also fulfill our citizens’ dreams and thirst for knowledge, and attract the young generation. This is the reason space exploration is an integral part of overall space activities. It has always been so, and it will be even more important in the future.”


    According to the ESA website, the activities are:

    Observing the Earth
    Human Spaceflight
    Space Science
    Space Engineering & Technology
    Telecommunications & Integrated Applications
    Preparing for the Future
    Space for Climate


    Copernicus Programme
    Cosmic Vision
    Horizon 2000
    Living Planet Programme


    Every member country must contribute to these programmes:

    Technology Development Element Programme
    Science Core Technology Programme
    General Study Programme
    European Component Initiative


    Depending on their individual choices the countries can contribute to the following programmes, listed according to:

    Earth Observation
    Human Spaceflight and Exploration
    Space Situational Awareness


    ESA has formed partnerships with universities. ESA_LAB@ refers to research laboratories at universities. Currently there are ESA_LAB@

    Technische Universität Darmstadt
    École des hautes études commerciales de Paris (HEC Paris)
    Université de recherche Paris Sciences et Lettres
    University of Central Lancashire

    Membership and contribution to ESA

    By 2015, ESA was an intergovernmental organisation of 22 member states. Member states participate to varying degrees in the mandatory (25% of total expenditures in 2008) and optional space programmes (75% of total expenditures in 2008). The 2008 budget amounted to €3.0 billion whilst the 2009 budget amounted to €3.6 billion. The total budget amounted to about €3.7 billion in 2010, €3.99 billion in 2011, €4.02 billion in 2012, €4.28 billion in 2013, €4.10 billion in 2014 and €4.33 billion in 2015. English is the main language within ESA. Additionally, official documents are also provided in German and documents regarding the Spacelab are also provided in Italian. If found appropriate, the agency may conduct its correspondence in any language of a member state.

    Non-full member states
    Since 2016, Slovenia has been an associated member of the ESA.

    Latvia became the second current associated member on 30 June 2020, when the Association Agreement was signed by ESA Director Jan Wörner and the Minister of Education and Science of Latvia, Ilga Šuplinska in Riga. The Saeima ratified it on July 27. Previously associated members were Austria, Norway and Finland, all of which later joined ESA as full members.

    Since 1 January 1979, Canada has had the special status of a Cooperating State within ESA. By virtue of this accord, the Canadian Space Agency takes part in ESA’s deliberative bodies and decision-making and also in ESA’s programmes and activities. Canadian firms can bid for and receive contracts to work on programmes. The accord has a provision ensuring a fair industrial return to Canada. The most recent Cooperation Agreement was signed on 15 December 2010 with a term extending to 2020. For 2014, Canada’s annual assessed contribution to the ESA general budget was €6,059,449 (CAD$8,559,050). For 2017, Canada has increased its annual contribution to €21,600,000 (CAD$30,000,000).


    After the decision of the ESA Council of 21/22 March 2001, the procedure for accession of the European states was detailed as described the document titled The Plan for European Co-operating States (PECS). Nations that want to become a full member of ESA do so in 3 stages. First a Cooperation Agreement is signed between the country and ESA. In this stage, the country has very limited financial responsibilities. If a country wants to co-operate more fully with ESA, it signs a European Cooperating State (ECS) Agreement. The ECS Agreement makes companies based in the country eligible for participation in ESA procurements. The country can also participate in all ESA programmes, except for the Basic Technology Research Programme. While the financial contribution of the country concerned increases, it is still much lower than that of a full member state. The agreement is normally followed by a Plan For European Cooperating State (or PECS Charter). This is a 5-year programme of basic research and development activities aimed at improving the nation’s space industry capacity. At the end of the 5-year period, the country can either begin negotiations to become a full member state or an associated state or sign a new PECS Charter.

    During the Ministerial Meeting in December 2014, ESA ministers approved a resolution calling for discussions to begin with Israel, Australia and South Africa on future association agreements. The ministers noted that “concrete cooperation is at an advanced stage” with these nations and that “prospects for mutual benefits are existing”.

    A separate space exploration strategy resolution calls for further co-operation with the United States, Russia and China on “LEO exploration, including a continuation of ISS cooperation and the development of a robust plan for the coordinated use of space transportation vehicles and systems for exploration purposes, participation in robotic missions for the exploration of the Moon, the robotic exploration of Mars, leading to a broad Mars Sample Return mission in which Europe should be involved as a full partner, and human missions beyond LEO in the longer term.”

    Relationship with the European Union

    The political perspective of the European Union (EU) was to make ESA an agency of the EU by 2014, although this date was not met. The EU member states provide most of ESA’s funding, and they are all either full ESA members or observers.


    At the time ESA was formed, its main goals did not encompass human space flight; rather it considered itself to be primarily a scientific research organisation for uncrewed space exploration in contrast to its American and Soviet counterparts. It is therefore not surprising that the first non-Soviet European in space was not an ESA astronaut on a European space craft; it was Czechoslovak Vladimír Remek who in 1978 became the first non-Soviet or American in space (the first man in space being Yuri Gagarin of the Soviet Union) – on a Soviet Soyuz spacecraft, followed by the Pole Mirosław Hermaszewski and East German Sigmund Jähn in the same year. This Soviet co-operation programme, known as Intercosmos, primarily involved the participation of Eastern bloc countries. In 1982, however, Jean-Loup Chrétien became the first non-Communist Bloc astronaut on a flight to the Soviet Salyut 7 space station.

    Because Chrétien did not officially fly into space as an ESA astronaut, but rather as a member of the French CNES astronaut corps, the German Ulf Merbold is considered the first ESA astronaut to fly into space. He participated in the STS-9 Space Shuttle mission that included the first use of the European-built Spacelab in 1983. STS-9 marked the beginning of an extensive ESA/NASA joint partnership that included dozens of space flights of ESA astronauts in the following years. Some of these missions with Spacelab were fully funded and organizationally and scientifically controlled by ESA (such as two missions by Germany and one by Japan) with European astronauts as full crew members rather than guests on board. Beside paying for Spacelab flights and seats on the shuttles, ESA continued its human space flight co-operation with the Soviet Union and later Russia, including numerous visits to Mir.

    During the latter half of the 1980s, European human space flights changed from being the exception to routine and therefore, in 1990, the European Astronaut Centre in Cologne, Germany was established. It selects and trains prospective astronauts and is responsible for the co-ordination with international partners, especially with regard to the International Space Station. As of 2006, the ESA astronaut corps officially included twelve members, including nationals from most large European countries except the United Kingdom.

    In the summer of 2008, ESA started to recruit new astronauts so that final selection would be due in spring 2009. Almost 10,000 people registered as astronaut candidates before registration ended in June 2008. 8,413 fulfilled the initial application criteria. Of the applicants, 918 were chosen to take part in the first stage of psychological testing, which narrowed down the field to 192. After two-stage psychological tests and medical evaluation in early 2009, as well as formal interviews, six new members of the European Astronaut Corps were selected – five men and one woman.

    Cooperation with other countries and organisations

    ESA has signed co-operation agreements with the following states that currently neither plan to integrate as tightly with ESA institutions as Canada, nor envision future membership of ESA: Argentina, Brazil, China, India (for the Chandrayan mission), Russia and Turkey.

    Additionally, ESA has joint projects with the European Union, NASA of the United States and is participating in the International Space Station together with the United States (NASA), Russia and Japan (JAXA).

    European Union
    ESA and EU member states
    ESA-only members
    EU-only members

    ESA is not an agency or body of the European Union (EU), and has non-EU countries (Norway, Switzerland, and the United Kingdom) as members. There are however ties between the two, with various agreements in place and being worked on, to define the legal status of ESA with regard to the EU.

    There are common goals between ESA and the EU. ESA has an EU liaison office in Brussels. On certain projects, the EU and ESA co-operate, such as the upcoming Galileo satellite navigation system. Space policy has since December 2009 been an area for voting in the European Council. Under the European Space Policy of 2007, the EU, ESA and its Member States committed themselves to increasing co-ordination of their activities and programmes and to organising their respective roles relating to space.

    The Lisbon Treaty of 2009 reinforces the case for space in Europe and strengthens the role of ESA as an R&D space agency. Article 189 of the Treaty gives the EU a mandate to elaborate a European space policy and take related measures, and provides that the EU should establish appropriate relations with ESA.

    Former Italian astronaut Umberto Guidoni, during his tenure as a Member of the European Parliament from 2004 to 2009, stressed the importance of the European Union as a driving force for space exploration, “…since other players are coming up such as India and China it is becoming ever more important that Europeans can have an independent access to space. We have to invest more into space research and technology in order to have an industry capable of competing with other international players.”

    The first EU-ESA International Conference on Human Space Exploration took place in Prague on 22 and 23 October 2009. A road map which would lead to a common vision and strategic planning in the area of space exploration was discussed. Ministers from all 29 EU and ESA members as well as members of parliament were in attendance.

    National space organisations of member states:

    The Centre National d’Études Spatiales(FR) (CNES) (National Centre for Space Study) is the French government space agency (administratively, a “public establishment of industrial and commercial character”). Its headquarters are in central Paris. CNES is the main participant on the Ariane project. Indeed, CNES designed and tested all Ariane family rockets (mainly from its centre in Évry near Paris)
    The UK Space Agency is a partnership of the UK government departments which are active in space. Through the UK Space Agency, the partners provide delegates to represent the UK on the various ESA governing bodies. Each partner funds its own programme.
    The Italian Space Agency A.S.I. – Agenzia Spaziale Italiana was founded in 1988 to promote, co-ordinate and conduct space activities in Italy. Operating under the Ministry of the Universities and of Scientific and Technological Research, the agency cooperates with numerous entities active in space technology and with the president of the Council of Ministers. Internationally, the ASI provides Italy’s delegation to the Council of the European Space Agency and to its subordinate bodies.
    The German Aerospace Center (DLR)[Deutsches Zentrum für Luft- und Raumfahrt e. V.] is the national research centre for aviation and space flight of the Federal Republic of Germany and of other member states in the Helmholtz Association. Its extensive research and development projects are included in national and international cooperative programmes. In addition to its research projects, the centre is the assigned space agency of Germany bestowing headquarters of German space flight activities and its associates.
    The Instituto Nacional de Técnica Aeroespacial (INTA)(ES) (National Institute for Aerospace Technique) is a Public Research Organization specialised in aerospace research and technology development in Spain. Among other functions, it serves as a platform for space research and acts as a significant testing facility for the aeronautic and space sector in the country.

    National Aeronautics Space Agency(US)

    ESA has a long history of collaboration with NASA. Since ESA’s astronaut corps was formed, the Space Shuttle has been the primary launch vehicle used by ESA’s astronauts to get into space through partnership programmes with NASA. In the 1980s and 1990s, the Spacelab programme was an ESA-NASA joint research programme that had ESA develop and manufacture orbital labs for the Space Shuttle for several flights on which ESA participate with astronauts in experiments.

    In robotic science mission and exploration missions, NASA has been ESA’s main partner. Cassini–Huygens was a joint NASA-ESA mission, along with the Infrared Space Observatory, INTEGRAL, SOHO, and others.

    Also, the Hubble Space Telescope is a joint project of NASA and ESA.

    Future ESA-NASA joint projects include the James Webb Space Telescope and the proposed Laser Interferometer Space Antenna.

    NASA has committed to provide support to ESA’s proposed MarcoPolo-R mission to return an asteroid sample to Earth for further analysis. NASA and ESA will also likely join together for a Mars Sample Return Mission. In October 2020 the ESA entered into a memorandum of understanding (MOU) with NASA to work together on the Artemis program, which will provide an orbiting lunar gateway and also accomplish the first manned lunar landing in 50 years, whose team will include the first woman on the Moon.

    Cooperation with other space agencies

    Since China has started to invest more money into space activities, the Chinese Space Agency(CN) has sought international partnerships. ESA is, beside the Russian Space Agency, one of its most important partners. Two space agencies cooperated in the development of the Double Star Mission. In 2017, ESA sent two astronauts to China for two weeks sea survival training with Chinese astronauts in Yantai, Shandong.

    ESA entered into a major joint venture with Russia in the form of the CSTS, the preparation of French Guiana spaceport for launches of Soyuz-2 rockets and other projects. With India, ESA agreed to send instruments into space aboard the ISRO’s Chandrayaan-1 in 2008. ESA is also co-operating with Japan, the most notable current project in collaboration with JAXA is the BepiColombo mission to Mercury.

    Speaking to reporters at an air show near Moscow in August 2011, ESA head Jean-Jacques Dordain said ESA and Russia’s Roskosmos space agency would “carry out the first flight to Mars together.”

  • richardmitnick 4:01 pm on September 9, 2021 Permalink | Reply
    Tags: "Earthlike planets in other solar systems? Look for moons", , , , , Planetary Science,   

    From University of Illinois at Urbana–Champaign (US) : “Earthlike planets in other solar systems? Look for moons” 

    From University of Illinois at Urbana–Champaign (US)

    Debra Levey Larson

    In this map of overlapping orbital resonances, the regions between resonances are colored black and could allow for stable satellite orbits under optimal conditions. The light green curve connects the first point of intersection between adjacent resonances and marks a stability boundary within the “three body problem”.

    Finding an exact copy of the Earth somewhere in the universe sounds like a far-fetched notion, but scientists believe that because Earth happened in our solar system, something similar is bound to exist someplace else. University of Illinois Urbana-Champaign researcher Siegfried Eggl and his colleagues say orbiting moons may play a key role in keeping planets habitable over long periods and identified a method to find them.

    “In our solar system, we have an average of 20 moons orbiting around each planet. So, we suspected there are moons around planets in other systems, too. There is really no reason why there shouldn’t be any,” said Eggl, a professor in the Department of Aerospace Engineering at UIUC.

    Eggl said astronomers using the Atacama Large Millimeter Array have recently observed what they believe is evidence of a moon forming around the extrasolar planet PDS 70c.

    The next step is finding moons around planets that have two stars.

    Some planets in other solar systems can be seen using very large telescopes like ALMA, the W.M. Keck observatory in Hawaii, or the European Southern Observatory’s VLT in Chile, but fully formed moons are still too tiny to spot.

    “We know they are there. We just need to look harder. But because it is so difficult to see them, we identified a way to detect them through the effect they have on a planet using transit timing variations.”

    Eggl said they can observe how planets behave in orbit and compare those observations to models with and without moons.

    “We know the planets, stars, and moons in our solar system interact gravitationally like a giant board game,” Eggl said. “The moon is tidally interacting with the Earth and slowing its own rotation, but the Sun is also there, tugging on both. A second star would act as another external perturber to the system.”

    When a planet passes in front of a star the star dims a little, Eggl said. A moon tugging on the planet is causing the planet to wobble slightly on its orbit. This wobble makes the darkening of the star occur sometimes earlier and other times later. In a double star system, additional variations in the time of transit are due to the forced, elliptical orbits of the planet and its moon. If detected, those variations can lead to additional insights into the properties of the system.

    Much like proving there is wind by observing tree branches bending, Eggl said “This is an indirect proof of a moon because there’s nothing else that could tug on the planet in that kind of fashion.”

    Of course, this assumes that planets did not lose their moons along the way.

    “We first had to determine the orbital resonances in the systems we looked at,” Eggl said. “When moons and planets have slightly elliptical orbits, they don’t always move at the same speed. The more eccentric an orbit, the more frequencies can be excited, and we see these resonances become more and more important. At some point there will be overlapping resonances that can lead to chaos in the system. In our study we have shown, however, that there is enough stable ‘real estate’ to merit a thorough search for moons around planets in double star systems.”

    Billy Quarles, lead author of the study, said, “The major difference with binary systems is the companion star acts like the tide at the beach, where it periodically comes in and etches away the beachfront. With a more eccentric binary orbit, a larger portion of the stable ‘real estate’ is removed. This can help out a lot in our search for moons in other star systems.”

    The bottom line for Eggl is that our solar system is probably not as special as we’d like to think it is.

    “If we can use this method to show there are other moons out there, then there are probably other systems similar to ours,” he said. “The moon is also likely critical for the evolution of life on our planet, because without the moon the axis tilt of the Earth wouldn’t be as stable, the results of which would be detrimental to climate stability. Other peer-reviewed studies have shown the relationship between moons and the possibility of complex life.”

    The study appears in The Astronomical Journal.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Illinois at Urbana-Champaign (US) community of students, scholars, and alumni is changing the world.
    The University of Illinois at Urbana–Champaign is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the University of Illinois system and was founded in 1867.
    The University of Illinois at Urbana–Champaign is a member of the Association of American Universities (US) and is classified among “R1: Doctoral Universities – Very high research activity”, and has been listed as a “Public Ivy” in The Public Ivies: America’s Flagship Public Universities (2001) by Howard and Matthew Greene. In fiscal year 2019, research expenditures at Illinois totaled $652 million. The campus library system possesses the second-largest university library in the United States by holdings after Harvard University (US). The university also hosts the National Center for Supercomputing Applications (US) (NCSA).

    The university contains 16 schools and colleges and offers more than 150 undergraduate and over 100 graduate programs of study. The university holds 651 buildings on 6,370 acres (2,578 ha). The University of Illinois at Urbana–Champaign also operates a Research Park home to innovation centers for over 90 start-up companies and multinational corporations, including Abbott, AbbVie, Caterpillar, Capital One, Dow, State Farm, and Yahoo, among others.

    As of August 2020, the alumni, faculty members, or researchers of the university include 30 Nobel laureates; 27 Pulitzer Prize winners; 2 Turing Award winners and 1 Fields medalist. Illinois athletic teams compete in Division I of the NCAA and are collectively known as the Fighting Illini. They are members of the Big Ten Conference and have won the second-most conference titles. Illinois Fighting Illini football won the Rose Bowl Game in 1947, 1952, 1964 and a total of five national championships. Illinois athletes have won 29 medals in Olympic events, ranking it among the top 40 American universities with Olympic medals.

    Illinois Industrial University

    The original University Hall, which stood until 1938, when it was replaced by Gregory Hall and the Illini Union. Pieces were used in the erection of Hallene Gateway dedicated in 1998.

    The University of Illinois, originally named “Illinois Industrial University”, was one of the 37 universities created under the first Morrill Land-Grant Act, which provided public land for the creation of agricultural and industrial colleges and universities across the United States. Among several cities, Urbana was selected in 1867 as the site for the new school. From the beginning, President John Milton Gregory’s desire to establish an institution firmly grounded in the liberal arts tradition was at odds with many state residents and lawmakers who wanted the university to offer classes based solely around “industrial education”. The university opened for classes on March 2, 1868 and had two faculty members and 77 students.

    The Library which opened with the school in 1868 started with 1,039 volumes. Subsequently President Edmund J. James in a speech to the board of trustees in 1912 proposed to create a research library. It is now one of the world’s largest public academic collections. In 1870 the Mumford House was constructed as a model farmhouse for the school’s experimental farm. The Mumford House remains the oldest structure on campus. The original University Hall (1871) was the fourth building built. It stood where the Illini Union stands today.

    University of Illinois

    In 1885, the Illinois Industrial University officially changed its name to the “University of Illinois”, reflecting its agricultural; mechanical; and liberal arts curriculum.

    During his presidency Edmund J. James (1904–1920) is credited for building the foundation for the large Chinese international student population on campus. James established ties with China through the Chinese Minister to the United States Wu Ting-Fang. In addition during James’s presidency class rivalries and Bob Zuppke’s winning football teams contributed to campus morale.
    Like many universities the economic depression slowed construction and expansion on the campus. The university replaced the original university hall with Gregory Hall and the Illini Union. After World War II the university experienced rapid growth. The enrollment doubled and the academic standing improved. This period was also marked by large growth in the Graduate College and increased federal support of scientific and technological research. During the 1950s and 1960s the university experienced the turmoil common on many American campuses. Among these were the water fights of the fifties and sixties.

    University of Illinois at Urbana–Champaign

    By 1967 the University of Illinois system consisted of a main campus in Champaign-Urbana and two Chicago campuses- Chicago Circle (UICC) and Medical Center (UIMC). People began using “Urbana–Champaign” or the reverse to refer to the main campus specifically. The university name officially changed to the “University of Illinois at Urbana–Champaign” around 1982. While this was a reversal of the commonly used designation for the metropolitan area- “Champaign-Urbana” – most of the campus is located in Urbana. The name change established a separate identity for the main campus within the University of Illinois system which today includes campuses in Springfield (UIS) and Chicago (UIC) (formed by the merger of UICC and UIMC).

    In 1998 the Hallene Gateway Plaza was dedicated. The Plaza features the original sandstone portal of University Hall which was originally the fourth building on campus. In recent years state support has declined from 4.5% of the state’s tax appropriations in 1980 to 2.28% in 2011- a nearly 50% decline. As a result the university’s budget has shifted away from relying on state support with nearly 84% of the budget now coming from other sources.

    On March 12, 2015, the Board of Trustees approved the creation of a medical school, the first college created at Urbana–Champaign in 60 years. The Carle-Illinois College of Medicine began classes in 2018.


    The University of Illinois at Urbana–Champaign is often regarded as a world-leading magnet for engineering and sciences (both applied and basic). Having been classified into the category comprehensive doctoral with medical/veterinary and very high research activity by The Carnegie Foundation for the Advancement of Teaching Illinois offers a wide range of disciplines in undergraduate and postgraduate programs.

    According to the National Science Foundation (US) the university spent $625 million on research and development in 2018 ranking it 37th in the nation. It is also listed as one of the Top 25 American Research Universities by The Center for Measuring University Performance. Beside annual influx of grants and sponsored projects the university manages an extensive modern research infrastructure. The university has been a leader in computer based education and hosted the PLATO project which was a precursor to the internet and resulted in the development of the plasma display. Illinois was a 2nd-generation ARPAnet site in 1971 and was the first institution to license the UNIX operating system from Bell Labs.

  • richardmitnick 11:25 am on September 2, 2021 Permalink | Reply
    Tags: "The forecast for Mars? Otherworldly weather predictions", Planetary Science, The scientists used a highly regarded global climate model for the moon called the Titan Atmospheric Model (TAM)., Understanding and predicting these space weather events is vital for the safety of missions particularly those that rely on solar power, Without accurate weather forecasts any trip to the surface of a planet or moon may be one dust storm away from disaster.,   

    From Yale University (US) : “The forecast for Mars? Otherworldly weather predictions” 

    From Yale University (US)

    August 30, 2021

    By Jim Shelton

    Media Contact:
    Fred Mamoun:

    (Illustration by Michael S. Helfenbein; Image JPL-Caltech (US).

    As scientists prepare for crewed research missions to nearby planets and moons, they’ve identified a need for something beyond rovers and rockets.

    They need accurate weather forecasts. Without them, any trip to the surface may be one dust storm away from disaster.

    A new Yale study helps lay the foundation for more accurate, otherworldly forecasts by taking a phenomenon related to Earth’s jet stream and applying it to weather patterns on Mars and Titan, Saturn’s largest moon. The study appears in the journal Nature Astronomy.

    “I believe the first accurate forecasts of perhaps a few Mars days may be only a decade away,” said lead author J. Michael Battalio, a postdoctoral researcher in Earth and planetary sciences in Yale’s Faculty of Arts and Sciences. “It is just a matter of combining better observational datasets with sufficiently refined numerical models.

    “But until then, we can rely upon connections between the climate and weather to help anticipate dust storms.”

    On Earth, the regularity of storm systems in the middle latitudes is associated with what is called an annular mode — a variability in atmospheric flow that is unrelated to the cycle of seasons. Annular modes affect the jet stream, precipitation, and cloud formations across the planet. They explain up to one-third of the variability in wind-driven “eddies,” including blizzards in New England and severe storm outbreaks in the Midwest.

    After noticing that the regularity of dust storms in the Southern Hemisphere of Mars was similar to the repeatability of Earth’s eddies, Battalio conceived of the new study. Specifically, after looking at 15 years of Mars atmospheric observations in a public dataset, he discovered that Mars also has annular modes, just as Earth does.

    Battalio’s lab supervisor, Juan Lora, an assistant professor of Earth and planetary sciences at Yale, suggested that they also look for annular modes on Titan. Although there are very few atmospheric observations for Titan, Lora has developed a highly regarded global climate model for the moon called the Titan Atmospheric Model (TAM).

    Indeed, Battalio and Lora found that annular modes are also prominent in their Titan simulations. In fact, the researchers found that annular modes on Titan — and on Mars — are even more influential than they are on Earth. They appear to be responsible for up to half of the wind variability on Mars and two-thirds of the wind variability on Titan.

    “Methane clouds and surface changes caused by methane rain on Titan have been observed before,” said Lora, who is co-author of the study. “And now it seems these events are connected to shifts of Titan’s strong jet stream, influenced by its annular modes.”

    Added Battalio: “The fact that we have found annular modes on worlds as different from Earth as Mars and Titan also means they may be ubiquitous in planetary atmospheres, from Venus, to the gas giants or exoplanets.”

    As for Mars, its dust storms range from tiny dust devils that are constantly occurring to global dust storms that encircle the planet once every few years. The smaller storms last less than a day, but the global events may last months. There are also regional events that last days to weeks.

    “Understanding and predicting these events is vital for the safety of missions particularly those that rely on solar power, but also for all missions as they land on the surface,” Battalio said. “During larger regional events, the dust can become so thick at times as to make day seem as dark as the middle of the night. Even without a large, dramatic event, regional storms are a periodic feature.”

    It is this periodic nature, researchers said, that could allow for annular modes to predict dust storms. Mars, Titan, and Earth’s modes each occur regularly. Because the annular modes impact the eddies that cause dust storms, real-time analysis of the annular modes enables simple predictions of dust storms without having to rely on a complex model.

    The Opportunity robotic rover landed on Mars in 2004 for a 90-day mission; it operated for more than 14 years, partly by hibernating during dust storms. The Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) robotic lander arrived on Mars in 2018.

    “A global event is what finally ended the Opportunity rover, but the slow accumulation of dust is currently endangering the survival of the InSight mission,” Battalio said.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    Yale University (US) is a private Ivy League research university in New Haven, Connecticut. Founded in 1701 as the Collegiate School, it is the third-oldest institution of higher education in the United States and one of the nine Colonial Colleges chartered before the American Revolution. The Collegiate School was renamed Yale College in 1718 to honor the school’s largest private benefactor for the first century of its existence, Elihu Yale. Yale University is consistently ranked as one of the top universities and is considered one of the most prestigious in the nation.

    Chartered by Connecticut Colony, the Collegiate School was established in 1701 by clergy to educate Congregational ministers before moving to New Haven in 1716. Originally restricted to theology and sacred languages, the curriculum began to incorporate humanities and sciences by the time of the American Revolution. In the 19th century, the college expanded into graduate and professional instruction, awarding the first PhD in the United States in 1861 and organizing as a university in 1887. Yale’s faculty and student populations grew after 1890 with rapid expansion of the physical campus and scientific research.

    Yale is organized into fourteen constituent schools: the original undergraduate college, the Yale Graduate School of Arts and Sciences and twelve professional schools. While the university is governed by the Yale Corporation, each school’s faculty oversees its curriculum and degree programs. In addition to a central campus in downtown New Haven, the university owns athletic facilities in western New Haven, a campus in West Haven, Connecticut, and forests and nature preserves throughout New England. As of June 2020, the university’s endowment was valued at $31.1 billion, the second largest of any educational institution. The Yale University Library, serving all constituent schools, holds more than 15 million volumes and is the third-largest academic library in the United States. Students compete in intercollegiate sports as the Yale Bulldogs in the NCAA Division I – Ivy League.

    As of October 2020, 65 Nobel laureates, five Fields Medalists, four Abel Prize laureates, and three Turing award winners have been affiliated with Yale University. In addition, Yale has graduated many notable alumni, including five U.S. Presidents, 19 U.S. Supreme Court Justices, 31 living billionaires, and many heads of state. Hundreds of members of Congress and many U.S. diplomats, 78 MacArthur Fellows, 252 Rhodes Scholars, 123 Marshall Scholars, and nine Mitchell Scholars have been affiliated with the university.


    Yale is a member of the Association of American Universities (AAU) (US) and is classified among “R1: Doctoral Universities – Very high research activity”. According to the National Science Foundation (US), Yale spent $990 million on research and development in 2018, ranking it 15th in the nation.

    Yale’s faculty include 61 members of the National Academy of Sciences (US), 7 members of the National Academy of Engineering (US) and 49 members of the American Academy of Arts and Sciences (US). The college is, after normalization for institution size, the tenth-largest baccalaureate source of doctoral degree recipients in the United States, and the largest such source within the Ivy League.

    Yale’s English and Comparative Literature departments were part of the New Criticism movement. Of the New Critics, Robert Penn Warren, W.K. Wimsatt, and Cleanth Brooks were all Yale faculty. Later, the Yale Comparative literature department became a center of American deconstruction. Jacques Derrida, the father of deconstruction, taught at the Department of Comparative Literature from the late seventies to mid-1980s. Several other Yale faculty members were also associated with deconstruction, forming the so-called “Yale School”. These included Paul de Man who taught in the Departments of Comparative Literature and French, J. Hillis Miller, Geoffrey Hartman (both taught in the Departments of English and Comparative Literature), and Harold Bloom (English), whose theoretical position was always somewhat specific, and who ultimately took a very different path from the rest of this group. Yale’s history department has also originated important intellectual trends. Historians C. Vann Woodward and David Brion Davis are credited with beginning in the 1960s and 1970s an important stream of southern historians; likewise, David Montgomery, a labor historian, advised many of the current generation of labor historians in the country. Yale’s Music School and Department fostered the growth of Music Theory in the latter half of the 20th century. The Journal of Music Theory was founded there in 1957; Allen Forte and David Lewin were influential teachers and scholars.

    In addition to eminent faculty members, Yale research relies heavily on the presence of roughly 1200 Postdocs from various national and international origin working in the multiple laboratories in the sciences, social sciences, humanities, and professional schools of the university. The university progressively recognized this working force with the recent creation of the Office for Postdoctoral Affairs and the Yale Postdoctoral Association.

    Notable alumni

    Over its history, Yale has produced many distinguished alumni in a variety of fields, ranging from the public to private sector. According to 2020 data, around 71% of undergraduates join the workforce, while the next largest majority of 16.6% go on to attend graduate or professional schools. Yale graduates have been recipients of 252 Rhodes Scholarships, 123 Marshall Scholarships, 67 Truman Scholarships, 21 Churchill Scholarships, and 9 Mitchell Scholarships. The university is also the second largest producer of Fulbright Scholars, with a total of 1,199 in its history and has produced 89 MacArthur Fellows. The U.S. Department of State Bureau of Educational and Cultural Affairs ranked Yale fifth among research institutions producing the most 2020–2021 Fulbright Scholars. Additionally, 31 living billionaires are Yale alumni.

    At Yale, one of the most popular undergraduate majors among Juniors and Seniors is political science, with many students going on to serve careers in government and politics. Former presidents who attended Yale for undergrad include William Howard Taft, George H. W. Bush, and George W. Bush while former presidents Gerald Ford and Bill Clinton attended Yale Law School. Former vice-president and influential antebellum era politician John C. Calhoun also graduated from Yale. Former world leaders include Italian prime minister Mario Monti, Turkish prime minister Tansu Çiller, Mexican president Ernesto Zedillo, German president Karl Carstens, Philippine president José Paciano Laurel, Latvian president Valdis Zatlers, Taiwanese premier Jiang Yi-huah, and Malawian president Peter Mutharika, among others. Prominent royals who graduated are Crown Princess Victoria of Sweden, and Olympia Bonaparte, Princess Napoléon.

    Yale alumni have had considerable presence in U.S. government in all three branches. On the U.S. Supreme Court, 19 justices have been Yale alumni, including current Associate Justices Sonia Sotomayor, Samuel Alito, Clarence Thomas, and Brett Kavanaugh. Numerous Yale alumni have been U.S. Senators, including current Senators Michael Bennet, Richard Blumenthal, Cory Booker, Sherrod Brown, Chris Coons, Amy Klobuchar, Ben Sasse, and Sheldon Whitehouse. Current and former cabinet members include Secretaries of State John Kerry, Hillary Clinton, Cyrus Vance, and Dean Acheson; U.S. Secretaries of the Treasury Oliver Wolcott, Robert Rubin, Nicholas F. Brady, Steven Mnuchin, and Janet Yellen; U.S. Attorneys General Nicholas Katzenbach, John Ashcroft, and Edward H. Levi; and many others. Peace Corps founder and American diplomat Sargent Shriver and public official and urban planner Robert Moses are Yale alumni.

    Yale has produced numerous award-winning authors and influential writers, like Nobel Prize in Literature laureate Sinclair Lewis and Pulitzer Prize winners Stephen Vincent Benét, Thornton Wilder, Doug Wright, and David McCullough. Academy Award winning actors, actresses, and directors include Jodie Foster, Paul Newman, Meryl Streep, Elia Kazan, George Roy Hill, Lupita Nyong’o, Oliver Stone, and Frances McDormand. Alumni from Yale have also made notable contributions to both music and the arts. Leading American composer from the 20th century Charles Ives, Broadway composer Cole Porter, Grammy award winner David Lang, and award-winning jazz pianist and composer Vijay Iyer all hail from Yale. Hugo Boss Prize winner Matthew Barney, famed American sculptor Richard Serra, President Barack Obama presidential portrait painter Kehinde Wiley, MacArthur Fellow and contemporary artist Sarah Sze, Pulitzer Prize winning cartoonist Garry Trudeau, and National Medal of Arts photorealist painter Chuck Close all graduated from Yale. Additional alumni include architect and Presidential Medal of Freedom winner Maya Lin, Pritzker Prize winner Norman Foster, and Gateway Arch designer Eero Saarinen. Journalists and pundits include Dick Cavett, Chris Cuomo, Anderson Cooper, William F. Buckley, Jr., and Fareed Zakaria.

    In business, Yale has had numerous alumni and former students go on to become founders of influential business, like William Boeing (Boeing, United Airlines), Briton Hadden and Henry Luce (Time Magazine), Stephen A. Schwarzman (Blackstone Group), Frederick W. Smith (FedEx), Juan Trippe (Pan Am), Harold Stanley (Morgan Stanley), Bing Gordon (Electronic Arts), and Ben Silbermann (Pinterest). Other business people from Yale include former chairman and CEO of Sears Holdings Edward Lampert, former Time Warner president Jeffrey Bewkes, former PepsiCo chairperson and CEO Indra Nooyi, sports agent Donald Dell, and investor/philanthropist Sir John Templeton,

    Yale alumni distinguished in academia include literary critic and historian Henry Louis Gates, economists Irving Fischer, Mahbub ul Haq, and Nobel Prize laureate Paul Krugman; Nobel Prize in Physics laureates Ernest Lawrence and Murray Gell-Mann; Fields Medalist John G. Thompson; Human Genome Project leader and National Institutes of Health (US) director Francis S. Collins; brain surgery pioneer Harvey Cushing; pioneering computer scientist Grace Hopper; influential mathematician and chemist Josiah Willard Gibbs; National Women’s Hall of Fame inductee and biochemist Florence B. Seibert; Turing Award recipient Ron Rivest; inventors Samuel F.B. Morse and Eli Whitney; Nobel Prize in Chemistry laureate John B. Goodenough; lexicographer Noah Webster; and theologians Jonathan Edwards and Reinhold Niebuhr.

    In the sporting arena, Yale alumni include baseball players Ron Darling and Craig Breslow and baseball executives Theo Epstein and George Weiss; football players Calvin Hill, Gary Fenick, Amos Alonzo Stagg, and “the Father of American Football” Walter Camp; ice hockey players Chris Higgins and Olympian Helen Resor; Olympic figure skaters Sarah Hughes and Nathan Chen; nine-time U.S. Squash men’s champion Julian Illingworth; Olympic swimmer Don Schollander; Olympic rowers Josh West and Rusty Wailes; Olympic sailor Stuart McNay; Olympic runner Frank Shorter; and others.

  • richardmitnick 11:13 am on August 28, 2021 Permalink | Reply
    Tags: "Unravelling the mystery of brown dwarfs", National Aeronautics Space Agency (US)/Massachusetts Institute of Technology (US) TESS, Planetary Science, So far we have only accurately characterised about 30 brown dwarfs.,   

    From University of Geneva [Université de Genève] (CH): “Unravelling the mystery of brown dwarfs” 

    From University of Geneva [Université de Genève] (CH)

    August 27, 2021

    Nolan Grieves
    Post-doctoral researcher
    Department of Astronomy
    Faculty of Science
    +41 22 379 24 01

    An international team, led by the Université de Genève, has investigated five astronomical objects that could help us understand the mysterious nature of brown dwarfs.

    This artist’s illustration represents the five brown dwarfs discovered with the satellite TESS. These objects are all in close orbits of 5-27 days (at least 3 times closer than Mercury is to the sun) around their much larger host stars. © 2021 Creatives Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) – Thibaut Roger – UNIGE

    Brown dwarfs are astronomical objects with masses between those of planets and stars. The question of where exactly the limits of their mass lie remains a matter of debate, especially since their constitution is very similar to that of low-mass stars. So how do we know whether we are dealing with a brown dwarf or a very low mass star? An international team, led by scientists from the University of Geneva (UNIGE) and the Swiss National Centres of Competence in Research (NCCRs) [Pôle national suisse de recherche en recherche][Schweizerisches Nationales Kompetenzzentrum für Forschung](CH) PlanetS, in collaboration with The University of Bern [CH], has identified five objects that have masses near the border separating stars and brown dwarfs that could help scientists understand the nature of these mysterious objects. The results can be found in the journal Astronomy & Astrophysics.

    Like Jupiter and other giant gas planets, stars are mainly made of hydrogen and helium. But unlike gas planets, stars are so massive and their gravitational force so powerful that hydrogen atoms fuse to produce helium, releasing huge amounts of energy and light.

    ‘Failed stars’

    Brown dwarfs, on the other hand, are not massive enough to fuse hydrogen and therefore cannot produce the enormous amount of light and heat of stars. Instead, they fuse relatively small stores of a heavier atomic version of hydrogen: deuterium. This process is less efficient and the light from brown dwarfs is much weaker than that from stars. This is why scientists often refer to them as ‘failed stars’.

    “However, we still do not know exactly where the mass limits of brown dwarfs lie, limits that allow them to be distinguished from low-mass stars that can burn hydrogen for many billions of years, whereas a brown dwarf will have a short burning stage and then a colder life”, points out Nolan Grieves, a researcher in the Department of Astronomy at the UNIGE’s Faculty of Science, a member of the NCCR PlanetS and the study’s first author. “These limits vary depending on the chemical composition of the brown dwarf, for example, or the way it formed, as well as its initial radius”, he explains. To get a better idea of what these mysterious objects are, we need to study examples in detail. But it turns out that they are rather rare. “So far we have only accurately characterised about 30 brown dwarfs”, says the Geneva-based researcher. Compared to the hundreds of planets that astronomers know in detail, this is very few. All the more so if one considers that their larger size makes brown dwarfs easier to detect than planets.

    New pieces to the puzzle

    Today, the international team characterized five companions that were originally identified with the Transiting Exoplanet Survey Satellite (TESS) as TESS objects of interest (TOI) – TOI-148, TOI-587, TOI-681, TOI-746 and TOI-1213.


    National Aeronautics Space Agency (US)/Massachusetts Institute of Technology (US) TESS

    NASA/MIT Tess in the building

    National Aeronautics Space Agency (US)/ Massachusetts Institute of Technology(US) TESS – Transiting Exoplanet Survey Satellite replaced the Kepler Space Telescope in search for exoplanets. TESS is a NASA Astrophysics Explorer mission led and operated by Massachusetts Institute of Technology (US), and managed by NASA’s Goddard Space Flight Center (US)

    Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA’s Ames Research Center in California’s Silicon Valley; the Center for Astrophysics – Harvard and Smithsonian; MIT Lincoln Laboratory; and the NASA Space Telescope Science Institute (US) in Baltimore.


    These are called ‘companions’ because they orbit their respective host stars. They do so with periods of 5 to 27 days, have radii between 0.81 and 1.66 times that of Jupiter and are between 77 and 98 times more massive. This places them on the borderline between brown dwarfs and stars.

    These five new objects therefore contain valuable information. “Each new discovery reveals additional clues about the nature of brown dwarfs and gives us a better understanding of how they form and why they are so rare”, says Monika Lendl, a researcher in the Department of Astronomy at the UNIGE and a member of the NCCR PlanetS.

    One of the clues the scientists found to show these objects are brown dwarfs is the relationship between their size and age, as explained by François Bouchy, professor at UNIGE and member of the NCCR PlanetS: “Brown dwarfs are supposed to shrink over time as they burn up their deuterium reserves and cool down. Here we found that the two oldest objects, TOI 148 and 746, have a smaller radius, while the two younger companions have larger radii.”

    Yet these objects are so close to the limit that they could just as easily be very low-mass stars, and astronomers are still unsure whether they are brown dwarfs. “Even with these additional objects, we still lack the numbers to draw definitive conclusions about the differences between brown dwarfs and low-mass stars. Further studies are needed to find out more”, concludes Grieves.

    See the full article here.


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Geneva [Université de Genève] (CH) is a public research university located in Geneva, Switzerland.

    It was founded in 1559 by John Calvin as a theological seminary and law school. It remained focused on theology until the 17th century, when it became a center for Enlightenment scholarship. In 1873, it dropped its religious affiliations and became officially secular. Today, the university is the third largest university in Switzerland by number of students. In 2009, the University of Geneva celebrated the 450th anniversary of its founding. Almost 40% of the students come from foreign countries.

    The university holds and actively pursues teaching, research, and community service as its primary objectives. In 2016, it was ranked 53rd worldwide by the Shanghai Academic Ranking of World Universities, 89th by the QS World University Rankings, and 131st in the TIMES Higher Education World University Ranking.

    UNIGE is a member of the League of European Research Universities (EU) (including academic institutions such as University of Amsterdam [Universiteit van Amsterdam] (NL), University of Cambridge (UK), Ruprecht Karl University of Heidelberg, [Ruprecht-Karls-Universität Heidelberg] (DE), University of Helsinki [ Helsingin yliopisto; Helsingfors universitet] (FI) and University of Milan [Università degli Studi di Milano Statale] (IT)) the Coimbra Group (EU) and the European University Association (EU).

    The University is composed of nine faculties:

    Faculty of Sciences
    Faculty of Medicine
    Faculty of Humanities
    Faculty Geneva School of Economics and Management (GSEM)
    Faculty Geneva School of Social Sciences (G3S)
    Faculty of Law (Geneva Law School)
    Faculty of Theology
    Faculty of Psychology and School of Education
    Faculty of Translation and Interpreting

    Interfaculty centers

    The university is composed of fourteen interfacultary centers. Amongst others:

    Institute for Reformation History (the Reformation)
    Computer Science Department (computer science)
    Institute for Environmental Sciences (energy policy)
    The Global Studies Institute
    Interfaculty Center of Gerontology (gerontology)
    Swiss Center for Affective Sciences (affective science)

    Associated institutions

    The university has also several partnerships with the nearby institutions, where students at the university may take courses.

    Graduate Institute of International and Development Studies (IHEID)
    Bossey Ecumenical Institute (of the World Council of Churches)
    Wyss Center for Bio- and Neuro-engineering
    Swiss National Supercomputing Centre
    Art-Law Centre
    Center for Biomedical Imaging(CIBM)
    University Centre of Legal Medicine (CURML)
    The Institute for Work and Health (IST)

  • richardmitnick 10:06 am on August 27, 2021 Permalink | Reply
    Tags: "Planet Nine-Scientists map its likely location", , , , , , Planetary Science   

    From EarthSky : “Planet Nine-Scientists map its likely location” 


    From EarthSky

    August 27, 2021
    Kelly Kizer Whitt

    A map of our sky. The red area is the most likely location for Plane Nine, a hypothetical, undiscovered planet in our solar system, according to the 2 astronomers who proposed Planet Nine’s existence in 2016. The wavy black line that echoes the colorful curve is the ecliptic, or path of the sun, moon and known planets in our sky. It makes sense that Planet Nine would lie somewhere along that colorful wavy line, these astronomers say. The red area indicates Planet Nine’s possible farthest region in orbit from our sun. That’s where Planet Nine would move most slowly and, therefore, spend most of its time. Search in the red area, these astronomers suggest! Image via Mike Brown.

    So where is it?

    William Herschel discovered Uranus in 1781. Johann Gottried Galle (and others) discovered Neptune in 1846. Clyde Tombaugh discovered Pluto in 1930. Whose name will fill in the blank for the discovery of Planet Nine? Will it be you? Your search just got easier, as last week two scientists provided a map (above) showing the probable orbit of Planet Nine, and its probable location within that orbit.

    Mike Brown and Konstantin Batygin, both of The California Institute of Technology (US), announced in early 2016 that they had evidence for a Planet Nine – another major planet in our solar system – lurking somewhere in our solar system’s outer realm. And now they’ve produced a map showing where the planet should lie. The Astronomical Journal accepted their new study on August 22, 2021.

    The map shows a wavy line projected on the sky tracing out the most likely path of Planet Nine. But where on that path is Planet Nine right now? As Brown said:

    “Sadly, the data only tell us the orbital path, not where in the orbital path it is (very sadly, actually). It is more likely to be at its most distant point from the sun, but only because it travels more slowly there. But this is where you should be looking.

    The paper [finally!] takes all of the observations of the outer solar system and tries to invert them to learn about the orbit and mass of Planet Nine in a statistically meaningful way. So, where is Planet Nine? Let me show you the treasure map.

    8:57 PM · Aug 23, 2021

    How they made the map

    Brown and Batygin examined the observations of all the known Kuiper Belt Objects with orbits affected by the unknown planet.

    Kuiper Belt Objects are icy bodies left over from the formation of the solar system that reside in an orbit out past Neptune. Pluto is a Kuiper Belt Object, and so are Eris, Makemake and Haumea. Many of these objects have eccentric orbits that Brown and Batygin believe are being affected by a distant and massive planet: Planet Nine.

    Teasing out information from these distant objects took a number of steps. The first step was to separate the tugs of Neptune on the objects from the pull of a more distant planet. The scientists also had to understand the observational bias in these objects (areas that surveys have heavily focused on versus areas that scientists have not examined as closely). They had to create a maximum likelihood model using a combination of numerical simulations and observations of each Kuiper Belt Object. This led them to parameters that show the most probable location for Planet Nine. Voila! We have a treasure map.

    Planet Nine: Just the stats

    From their calculations taken from Kuiper Belt Objects, the scientists came up with approximate figures for Planet Nine. They estimate Planet Nine to be about 6.2 Earth masses, with an orbit that takes it from 300 astronomical units (AU, with 1 AU being the distance from Earth to the sun) out to 380 AU from the sun. Planet Nine’s orbital inclination, or how much it tilts away from the plane of the solar system, is around 16 degrees. Compare that to Earth’s orbital inclination, which is zero degrees, and Pluto’s, which is 17 degrees.

    How bright is Planet Nine?

    The brightness of Planet Nine depends on where it’s located in its orbit at the time. The closer the planet is to us in its orbit, the brighter it will be, and vice versa. But the average brightness of Planet Nine should be about magnitude 22. Pluto’s average magnitude is around 15, and it can only be seen by telescopes that are 10 inches or larger.

    When a Twitter user asked Brown why we can’t see Planet Nine, Brown answered:

    “It’s easy to see, but hard to find. It’s like if I show you a grain of sand. No problem seeing it. Now throw it on the beach and try to refind it. Every star in the sky is like a grain of sand in which Planet Nine hides.”

    This graph shows how Planet Nine affects the locations of Kuiper Belt Objects. Image via Mike Brown.

    Kuiper Belt Objects getting jerked around

    The scientists shared the graph above to show how Kuiper Belt Objects are affected by the presence of Planet Nine. The green circles are known Kuiper Belt Objects. The lighter areas of the vertical blue bars are where scientists would expect to find the objects. These are biased locations, because two different surveys have taken more observations in these areas. Thus, this is where we should have spotted more objects. But the objects cluster near the reddish-orange strip in the center, which is where we would find them if something large lurking in the darkness were affecting them.

    This graph shows us another view of clustering that favors the likelihood of Planet Nine. Image via Mike Brown.

    The round graphs show the objects’ tilt away from the plane of the solar system. A point in the middle would be an object that has the same tilt as the planets. The red graph shows where the Kuiper Belt Objects should be if Planet Nine is tugging on them. The blue graph shows where the Kuiper Belt Objects should be (along the faint crisscrossing lines where the surveys looked for objects) based on observational bias. But the objects don’t align with the blue graph as closely as the red graph. Planet Nine’s tilt is about 16 degrees, and the objects show an average tilt of about 15 degrees.

    The clustered objects – instead of being evenly distributed – indicate they’re being influenced by a massive, undiscovered planet. As Mike Brown said on his blog:

    “Put these two plots together and you get a 99.6% chance that the objects are clustered, rather than uniform. That sounds pretty good to me.”

    See the full article here .

    Please help promote STEM in your local schools.

    Stem Education Coalition

    Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.orgin 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. “Being an EarthSky editor is like hosting a big global party for cool nature-lovers,” she says.

  • richardmitnick 8:34 am on August 27, 2021 Permalink | Reply
    Tags: "Like Star like Planet", , Planetary Science,   

    From University of Zürich (Universität Zürich) (CH): “Like Star like Planet” 

    From University of Zürich (Universität Zürich) (CH)

    24 Aug 2021

    Ravit Helled
    Center for Theoretical Astrophysics & Cosmology.
    Institute for Computational Science, University of Zürich.
    Winterthurerstr. 190 CH-8057 Zürich Switzerland
    Irchel Campus, Y11, F84

    Arian Bastani

    One of the patterns emerging from the thousands of exoplanets that astronomers have discovered to date, is that the larger planets often orbit more massive stars. The reason behind it was unknown. A new study led by scientists at the University of Zürich, and members associated with the National Center of Competence in Research (NCCR) PlanetS offers an answer to this cosmic mystery.

    The largest planet in our solar system: Jupiter photographed by NASA’s Juno and Cassini spacecraft. Image: Kevin Gill/Maksim Kakitsev/NASA/JPL-Caltech (US)/Southwest Research Institute (US)/Malin Space Science Systems(US).

    Tall people often have tall parents. Short people usually do not. What generations of humans had observed was finally explained by genetics: children inherit their parents’ genes and therefore share many of their traits. In some ways, stars and planets have similar relationships as parents and their children. For example, stars are older than their planets, they are larger and control much of what happens to the planets they host. Often, the star that a planet orbits is referred to as its “mother star”. But how much is there to this analogy? Do stars “pass on” some of their characteristics to the planets that orbit them – like, for example, their size? Researchers at the University of Zürich found that there is at least some truth to it, as their results published in the journal Astronomy & Astrophysics suggest.

    A cosmic puzzle

    “Over the last years, astronomers have found that more massive stars tend to host larger planets,” Michael Lozovsky, first author of the study, former doctoral researcher at the University of Zürich and associated with the NCCR PlanetS begins to explain. “While this seems intuitive at first glance, the reason behind it is not obvious and there haven’t been any rigorous attempts to explain it,” Lozovsky points out.

    Unlike children, however, planets are not “born” by their star. Instead, they form from the same cosmic gas and dust. They do so with some delay – the stars begin to form earlier – but the star is often not mature while the planets begin to arise. A form of “heritage”, as in humans, is therefore not the reason that massive stars host larger planets.

    But the following three theories that Lozovsky and his colleagues formulated could explain the pattern:

    Planets around more massive stars are hotter: larger stars are hotter and emit more energy than smaller stars. This heats up their surrounding planets more strongly and as the planets get hotter, they inflate and become larger.

    Planets around more massive stars are more massive: since the size of a planet increases with mass, it could be that stars that are more massive host larger planets simply because the planets themselves are also more massive.

    Planets around more massive stars have lighter atmospheres: the atmosphere surrounding the planet can also be an important factor for its size. If larger stars tend to host planets with atmospheres consisting of light gases such as hydrogen and helium, this could also explain their larger size and the observed pattern.

    Light gases make large planets

    Using National Aeronautics Space Agency (US) databases, the team first looked at the available information on thousands of planets. Like for example temperature and size. “If larger planets were indeed hotter it would have been visible in the data. However, what we found was the opposite: hotter planets are sometimes even smaller, possibly because the strong stellar radiation evaporates some of their atmosphere,” Lozovsky says.

    Testing the other two theories required more than statistics. “Using dedicated computer models, we simulated how planet sizes would change when their mass increased”, Lozovsky explains. What the team found, is that planets don’t become significantly larger for a given added mass but that they rather become denser instead. Therefore, the researchers also rejected this explanation and were left with the third theory, stating that the planets’ larger size comes from higher shares of light gases. “This time we found a clear signal – varying the planets’ compositions had a large effect on their size and could therefore explain the observed relationship to star mass. This also tells us that larger stars tend to host planets with more massive atmospheres,” Lozovsky reports.

    “The results not only help us estimate which kinds of planets likely orbit a certain star, but could also help us fill gaps in our understanding of planet formation,” co-author, NCCR PlanetS member and professor of computational astronomy at the University of Zurich, Ravit Helled points out. Based on their findings, the researchers conclude that planets around larger stars tend to collect gases more quickly during their formation. This is important, because the gas and dust from which the planets form, begins to evaporate as the star grows and radiates more strongly. Thus, the planets only have limited time to grow and acquire what they need for their later existence – perhaps not entirely unlike children, who are expected to stand on their own feet eventually.

    See the full article here .


    Please help promote STEM in your local schools.

    Stem Education Coalition

    The University of Zürich (Universität Zürich) (CH), located in the city of Zürich, is the largest university in Switzerland, with over 26,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy.

    Currently, the university has seven faculties: Philosophy, Human Medicine, Economic Sciences, Law, Mathematics and Natural Sciences, Theology and Veterinary Medicine. The university offers the widest range of subjects and courses of any Swiss higher education institutions.
    Since 1833

    As a member of the League of European Research Universities (EU) (LERU) and Universitas 21 (U21) network, the University of Zürich belongs to Europe’s most prestigious research institutions. In 2017, the University of Zürich became a member of the Universitas 21 (U21) network, a global network of 27 research universities from around the world, promoting research collaboration and exchange of knowledge.

    Numerous distinctions highlight the University’s international renown in the fields of medicine, immunology, genetics, neuroscience and structural biology as well as in economics. To date, the Nobel Prize has been conferred on twelve UZH scholars.

    Sharing Knowledge

    The academic excellence of the University of Zürich brings benefits to both the public and the private sectors not only in the Canton of Zürich, but throughout Switzerland. Knowledge is shared in a variety of ways: in addition to granting the general public access to its twelve museums and many of its libraries, the University makes findings from cutting-edge research available to the public in accessible and engaging lecture series and panel discussions.

    1. Identity of the University of Zürich


    The University of Zürich (UZH) is an institution with a strong commitment to the free and open pursuit of scholarship.

    Scholarship is the acquisition, the advancement and the dissemination of knowledge in a methodological and critical manner.

    Academic freedom and responsibility

    To flourish, scholarship must be free from external influences, constraints and ideological pressures. The University of Zürich is committed to unrestricted freedom in research and teaching.

    Academic freedom calls for a high degree of responsibility, including reflection on the ethical implications of research activities for humans, animals and the environment.


    Work in all disciplines at the University is based on a scholarly inquiry into the realities of our world

    As Switzerland’s largest university, the University of Zürich promotes wide diversity in both scholarship and in the fields of study offered. The University fosters free dialogue, respects the individual characteristics of the disciplines, and advances interdisciplinary work.

    2. The University of Zurich’s goals and responsibilities

    Basic principles

    UZH pursues scholarly research and teaching, and provides services for the benefit of the public.

    UZH has successfully positioned itself among the world’s foremost universities. The University attracts the best researchers and students, and promotes junior scholars at all levels of their academic career.

    UZH sets priorities in research and teaching by considering academic requirements and the needs of society. These priorities presuppose basic research and interdisciplinary methods.

    UZH strives to uphold the highest quality in all its activities.
    To secure and improve quality, the University regularly monitors and evaluates its performance.


    UZH contributes to the increase of knowledge through the pursuit of cutting-edge research.

    UZH is primarily a research institution. As such, it enables and expects its members to conduct research, and supports them in doing so.

    While basic research is the core focus at UZH, the University also pursues applied research.

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