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  • richardmitnick 8:49 am on October 14, 2021 Permalink | Reply
    Tags: "NASA’s Lucy spacecraft poised to launch Oct. 16. 2021", Asteroids, Jupiter Trojan asteroids,   

    From Southwest Research Institute (US) : “NASA’s Lucy spacecraft poised to launch Oct. 16. 2021” 

    SwRI bloc

    From Southwest Research Institute (US)

    October 12, 2021

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    Workers prepare the Lucy spacecraft for launch from Cape Canaveral. The launch date is set for Saturday, October 16, 2021. Image via SwRI.

    NASA’s Lucy spacecraft is encapsulated in a protective fairing atop an Atlas V rocket, awaiting its 23-day launch window to open on October 16. All is go for the Southwest Research Institute-led mission to begin, as the spacecraft prepares to launch on a 12-year journey of almost 4 billion miles to visit a record-breaking eight asteroids — one main belt asteroid and seven Jupiter Trojan asteroids.

    “The Trojan asteroids are leftovers from the early days of our solar system, effectively fossils of the planet formation process,” said SwRI’s Harold Levison, the principal investigator of the mission. “They hold vital clues to deciphering the history of our solar system. Lucy, like the human ancestor fossil for which it is named, will revolutionize the understanding of our origins.”

    The Lucy mission is the first space mission to explore this diverse population of small bodies known as the Jupiter Trojan asteroids. These small bodies are trapped in stable orbits shared with the solar system’s largest planet, forming two “swarms” that lead and trail Jupiter in its path around the Sun.

    “Lucy’s ability to fly by so many targets means that we will not only get the first up-close look at this unexplored population, but we will also be able to study why these asteroids appear so different,” said SwRI’s Cathy Olkin, deputy principal investigator of the mission. “The mission will provide an unparalleled glimpse into the formation of our solar system, helping us understand the evolution of the planetary system as a whole.”

    Following pandemic protocols, Lucy team members have spent nearly two months at NASA’s Kennedy Space Center in Florida preparing the spacecraft for flight. Engineers have tested the spacecraft’s mechanical, electrical and thermal systems, and they have practiced executing the launch sequence from the mission operations centers at Kennedy and Lockheed Martin Space in Littleton, Colorado.

    “Launching a spacecraft is almost like sending a child off to college — you’ve done what you can to get them ready for that next big step on their own,” Levison said. “Lucy is ready to fly.”

    Lucy’s first launch attempt is scheduled for 5:34 a.m. EDT on October 16. That day, the team will be “called to stations” at 1 a.m. to monitor the spacecraft and run through the full launch countdown procedures. If weather or any other issues scrub launch that day, the team will have additional launch opportunities every morning over the next couple of weeks.

    SwRI is the principal investigator institution for Lucy. The Goddard Space Flight Center | NASA (US) provides overall mission management, systems engineering, and safety and mission assurance. Lockheed Martin Space in Littleton, Colorado, built the spacecraft. Lucy is the 13th mission in NASA Discovery Program (US). NASA Marshall Space Flight Center (US), manages the Discovery Program for NASA’s Science Mission Directorate in Washington. The launch is managed by NASA’s Launch Services Program based at Kennedy.

    See the full article here .

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    SwRI Campus

    Southwest Research Institute (SwRI) (US) is an independent, nonprofit applied research and development organization. The staff of nearly 2,800 specializes in the creation and transfer of technology in engineering and the physical sciences. SwRI’s technical divisions offer a wide range of technical expertise and services in such areas as engine design and development, emissions certification testing, fuels and lubricants evaluation, chemistry, space science, nondestructive evaluation, automation, mechanical engineering, electronics, and more.

    Southwest Research Institute (SwRI), headquartered in San Antonio, Texas, is one of the oldest and largest independent, nonprofit, applied research and development (R&D) organizations in the United States. Founded in 1947 by oil businessman Tom Slick, SwRI provides contract research and development services to government and industrial clients.

    The institute consists of nine technical divisions that offer multidisciplinary, problem-solving services in a variety of areas in engineering and the physical sciences. The Center for Nuclear Waste Regulatory Analyses, a federally funded research and development center sponsored by the U.S. Nuclear Regulatory Commission, also operates on the SwRI grounds. More than 4,000 projects are active at the institute at any given time. These projects are funded almost equally between the government and commercial sectors. At the close of fiscal year 2019, the staff numbered approximately 3,000 employees and research volume was almost $674 million. The institute provided more than $8.7 million to fund innovative research through its internally sponsored R&D program.

    A partial listing of research areas includes space science and engineering; automation; robotics and intelligent systems; avionics and support systems; bioengineering; chemistry and chemical engineering; corrosion and electrochemistry; earth and planetary sciences; emissions research; engineering mechanics; fire technology; fluid systems and machinery dynamics; and fuels and lubricants. Additional areas include geochemistry and mining engineering; hydrology and geohydrology; materials sciences and fracture mechanics; modeling and simulation; nondestructive evaluation; oil and gas exploration; pipeline technology; surface modification and coatings; and vehicle, engine, and powertrain design, research and development. In 2019, staff members published 673 papers in the technical literature; made 618 presentations at technical conferences, seminars and symposia around the world; submitted 48 invention disclosures; filed 33 patent applications; and received 41 U.S. patent awards.

    SwRI research scientists have led several National Aeronautics Space Agency(USA) missions, including the New Horizons mission to Pluto; the Juno mission to Jupiter; and the Magnetospheric Multiscale Mission(US) to study the Earth’s magnetosphere.

    SwRI initiates contracts with clients based on consultations and prepares a formal proposal outlining the scope of work. Subject to client wishes, programs are kept confidential. As part of a long-held tradition, patent rights arising from sponsored research are often assigned to the client. SwRI generally retains the rights to institute-funded advancements.

    The institute’s headquarters occupy more than 2.3 million square feet of office and laboratory space on more than 1,200 acres in San Antonio. SwRI has technical offices and laboratories in Boulder, Colorado; Ann Arbor, Michigan; Warner-Robins, Georgia; Ogden, Utah; Oklahoma City, Oklahoma; Rockville, Maryland; Minneapolis, Minnesota; Beijing, China; and other locations.

    Technology Today, SwRI’s technical magazine, is published three times each year to spotlight the research and development projects currently underway. A complementary Technology Today podcast offers a new way to listen and learn about the technology, science, engineering, and research impacting lives and changing our world.

     
  • richardmitnick 12:06 pm on July 1, 2021 Permalink | Reply
    Tags: "Q&A- How we’re gearing up to deflect asteroids that might cause Earth considerable damage", Asteroids, Dr Naomi Murdoch, , ,   

    From Horizon The EU Research and Innovation Magazine : “Q&A- How we’re gearing up to deflect asteroids that might cause Earth considerable damage” 

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    From Horizon The EU Research and Innovation Magazine

    06 April 2021 [Why now!! This just showed up in social media.]
    Natalie Grover

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    “Asteroids hold clues about how our solar system formed. Their physical makeup and composition can also help answer the big question of how life emerged”, tells Dr Naomi Murdoch, planetary scientist specialised in the geophysical evolution of asteroids at the French aeronautics and space institute National Higher School of Mechanics and Aerotechnics [ISAE-ENSMA // École Nationale Supérieure de Mécanique et d’Aérotechnique | Le site de l’école ISAE-ENSMA situé au Futuroscope de Poitiers. (FR). Image credit – Naomi Murdoch.

    Asteroids — the bits and pieces left over from the formation of the inner planets — are a source of great curiosity for those keen to learn about the building blocks of our solar system, and to probe the chemistry of life.

    Humans are also considering mining asteroids for metals, but one of the crucial reasons scientists study this ancient space rubble is planetary defense, given the potential for space debris to cause Earth harm.

    Accordingly, NASA is planning a 2022 planetary defense mission that involves sending a spacecraft to crash into a near-Earth asteroid in an effort to check whether it could be deflected were it on a collision course with Earth.

    Dr Naomi Murdoch — a planetary scientist at the French aeronautics and space institute ISAE-SUPAERO, who specialises in the geophysical evolution of asteroids — is part of a follow-on mission planned by the European Space Agency [Agence spatiale européenne][Europäische Weltraumorganisation](EU).

    She tells Horizon about the mission will characterise the asteroid after impact to obtain data that will inform strategies designed to address any threatening asteroids that might come Earth’s way.

    But are we in any real danger of being wiped out by a big rocky remnant? Not really, but some asteroids can cause considerable damage, which is why we’re shoring up our defences here on Earth, she suggests.

    What makes asteroids interesting?

    Asteroids hold clues about how our solar system formed. Their physical makeup and composition can also help answer the big question of how life emerged.

    How many have we identified – and what are they made of?

    So far, we have identified more than a million asteroids, but there are tens, if not hundreds of millions out there that we don’t know about. This is because unlike stars, asteroids don’t emit a light of their own, they only reflect sunlight, so many of the smaller ones are difficult to spot.

    What they are made of depends on where they were formed in the solar system. The ones that formed closest to the sun have borne the brunt of the heat, losing material that could have been really interesting to study. But the most common ones are those that formed furthest away from the sun: the C (carbonaceous)-type, likely consisting of clay and silicate rocks, are among the most ancient objects in the solar system but are hard to detect because they are relatively dark in colour.

    Then there are brighter options. The M (metallic)-type, composed mainly of metallic iron, largely inhabit the asteroid belt’s middle section. (The asteroid belt lies roughly between Mars and Jupiter). The S (stony)-type, comprising silicate materials and nickel-iron, are most commonly found in the inner asteroid belt.

    Most meteorites (a small piece of an asteroid or comet that survives the journey across Earth’s atmosphere) found on Earth are either metallic or stony. It is less likely that the carbonaceous type will be found on the ground, unless the asteroids were quite large because they have to survive our planet’s atmosphere without completely burning up. Basically, the types of meteorites that we find on the ground are not necessarily representative of the type of asteroids that would even hit our atmosphere.

    So what kind of asteroid are scientists wary of in terms of the danger they pose to our planet?

    Any asteroid size could in principle, hit us, but the largest asteroids are easy to detect — we’ve identified the vast majority of them and they’re not risky. There are many, many more small asteroids than there are large ones, and because they’re small, they’re really difficult to detect and difficult to follow. We have to look for them several times in order to pinpoint their orbit to know where they’re going to be in space.

    What we focus on are those (small asteroids) in the 100-to-500-metre size range. This size range is probably the most dangerous because they could still cause a large amount of damage on Earth, for example on a regional and national scale. But we don’t know yet where they all are, which is why this is the key size range for planetary defence, because there’s a risk of discovering one day that one we didn’t know existed is coming towards us.

    Space scientists are trying to improve our ability to detect these smaller asteroids, then assess whether they are threats, and finally, if need be, (we try to) deflect the object.

    As part of the NEO-MAPP project, we are helping prepare for these planetary defence missions by improving space instruments that are linked to measuring properties of the surface, the subsurface and the internal structure of asteroids, because it’s these parameters that will govern whether a deflection mission is successful or not. Another objective is to develop a better understanding of landing on asteroids, of the consequences of their low gravity environment, and how to interpret data recorded during surface interactions.

    Once you’ve detected an asteroid you want to explore, how do you go about landing on one?

    Before the first space missions, many people thought that asteroids were just boring lumps of rock, but we started to realise that they were actually a lot more interesting. They have their own evolutionary history, which is really important to understand the solar system in general.

    The only way to really probe the mechanical and physical properties of an asteroid is to touch and interact directly with it, but we don’t have a good understanding of the actual surface of asteroids, which harbour a low-gravity environment. It’s a really exotic place, typically covered by granular material like sand, rocks, boulders, depending on the type of asteroid and its size. And this granular material, in that low gravity environment, appears to behave much more like a fluid than the same material would behave on Earth.

    As a result, previous missions have had varying degrees of landing success so we are now studying landing behaviour in gravitational conditions similar to those on asteroids.

    You are part of the European Space Agency’s Hera mission, which will follow-on from NASA’s DART mission to a binary asteroid system. What are these missions hoping to achieve?

    DART is an upcoming planetary defence mission designed to collide with a smaller asteroid moon, called Dimorphos, orbiting with the near-Earth asteroid Didymos. The idea is to test whether Dimorphos’s orbit can be deflected. In the days following, we’ll know whether the deflection was successful or not. Then, Hera will survey and characterise the asteroid pair and the resulting crater.

    The main Hera spacecraft will not touch the surface, and will perform all of the investigations in orbit around the asteroids. However, mini satellites called cubesats will land on the moon. One, for instance, will orbit and study the asteroid (the main instrument is a radar for looking inside it), and then it will descend to the surface. The landing part of the mission is ‘bonus science’ (not necessary to achieve the mission goals), but extremely interesting in order to characterise the physical properties of the asteroid.

    The idea behind these missions is to test a key deflection method and to understand the target. Although Dimorphos is not a threat to Earth, it is a size that is roughly in line with potentially threatening asteroids. What we want to do is have a well-characterised, large-scale experiment that we can use to extrapolate to any potential asteroid threats. In order to do that we need to learn about our targets, including their form, mass density, the impact crater size and the level of debris generated upon collision.

    By measuring the physical properties and characterising the target in detail we can calibrate our numerical (impact) models. If one day a potentially dangerous asteroid comes our way, we can use these models to predict what may happen if we try to deflect it.

    Another feature of Hera is the plan to take a look inside the moon. I think it’s going to be extremely exciting to see what’s in there, because that’s going to tell us a lot about the history of the asteroid-moon pair.

    So we’re gearing up to tackle any asteroids that might cause Earth some damage. But how likely are we to be wiped out completely by an asteroid?

    Small asteroids, including pieces tiny enough to be called space dust, hit our atmosphere every day — that is what shooting stars are. The probability of an asteroid causing large-scale damage is very small. That 100-to-500-metre size range is the most threatening range — so that’s what scientists are working on at the moment.

    Overall, we can all sleep soundly knowing that it is extremely unlikely that we’re going to be wiped out by an asteroid.

    See the full article here .


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  • richardmitnick 6:37 pm on November 12, 2020 Permalink | Reply
    Tags: "DES­TINY+: Ger­many and Japan be­gin new as­ter­oid mis­sion", Asteroids, From DLR German Aerospace Center (DE), JAXA (JP),   

    From DLR German Aerospace Center (DE) “DES­TINY+: Ger­many and Japan be­gin new as­ter­oid mis­sion” 

    DLR Bloc

    From DLR German Aerospace Center (DE)

    DLR (DE) and JAXA (JP) sign cooperation agreement for a bilateral mission during their joint strategy dialogue meeting.

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    As­ter­oid ex­plor­er DES­TINY+. Credit: JAXA (JP)/Kashikagaku.

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    Cross-sec­tion­al view of the DES­TINY+ Dust An­a­lyz­er (DDA) dust in­stru­ment. Credit: IRS, University Stuttgart (DE)

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    As­ter­oid Phaethon. Credit: ESA (EU)/P. Carril.

    In 2024, the Japanese-German space mission DESTINY+ will launch on a journey to asteroid 3200 Phaethon.
    The mission’s key instrument is the German DESTINY+ Dust Analyzer (DDA), which will collect and analyse cosmic dust samples during the entire flight of the spacecraft.
    The cooperation agreement for the bilateral mission was signed by DLR and JAXA on 11 November 2020 as part of a joint strategy dialogue meeting.

    Focus: Space

    How did life arrive on Earth? To investigate this and to address fundamental questions about the evolution of celestial bodies in our Solar System, the Japanese-German space mission DESTINY+ (Demonstration and Experiment of Space Technology for INterplanetary voYage with Phaethon fLyby and dUst Science), will launch in 2024 on a journey to asteroid 3200 Phaethon. The German DESTINY+ Dust Analyzer (DDA) instrument on board the Japanese spacecraft will examine cosmic dust during the entire cruise phase to Phaethon, with dust particles that have escaped from the asteroid and are measured in its vicinity of particular interest to scientists. The cooperation agreement for the bilateral mission was signed on 11 November 2020 by Walther Pelzer, German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR (DE)) Executive Board Member and Head of the DLR Space Administration, and Hitoshi Kuninaka, Vice President of the Japan Aerospace Exploration Agency (JAXA) (JP). The signing ceremony was part of the joint strategy dialogue meeting between DLR and JAXA.

    Asteroid Phaethon

    “This mission once again underlines the benefits of bilateral cooperation between equal partners, as is the case with Germany and Japan,” explains Pelzer. “With DESTINY+, we are continuing our successful cooperation on missions such as Hayabusa2 (JP), Martian Moons eXploration (MMX) and BepiColombo, and we are pleased to be able to make an important contribution to space research with the DDA dust instrument.”

    JAXA (JP)/Hayabusa 2 Credit: JAXA/Akihiro Ikeshita.

    JAXA (JP) MMX spacecraft

    Artistic rendition ESA (EU)/JAXA (JP) BepiColombo

    In mid-2024, the DESTINY+ spacecraft is scheduled to launch on an Epsilon S launch vehicle from the Uchinoura Space Center(JP), beginning a four-year journey to asteroid 3200 Phaethon. This celestial body is thought to be the origin of a cloud of dust orbiting the Sun, which rains a shower of meteors – referred to as the Geminids – onto Earth every December.

    “With a minimum approach distance of approximately 21 million kilometres, Phaethon gets closer to the Sun than the planet Mercury,” explains Carsten Henselowsky, DESTINY+ Project Manager at the DLR Space Administration. “In the process, its surface heats up to a temperature of over 700 degrees Celsius, causing the celestial body to release more dust particles. The aim of the DESTINY+ mission is to investigate such cosmic dust particles and to determine whether the arrival of extraterrestrial dust particles on Earth may have played a role in the creation of life on our planet.” During its flyby the spacecraft will approach the asteroid down to a distance of approximately 500 kilometres, at which point the asteroid itself will be approximately 150 million kilometres from the Sun.

    German dust instrument DDA is key instrument for the mission

    The mission’s key instrument is the German DDA dust instrument. This high-resolution mass spectrometer will collect and analyse cosmic dust particles in the vicinity of Phaethon upon flyby and during its entire journey. The measurements will pin down the origin of each dust particle. Of particular interest is the proportion of organic matter; scientists suspect that organic compounds and the associated elements, such as carbon – the basic building block for all life forms on Earth – may have been delivered to our planet by such dust particles. A telescopic camera, TCAP, and a multiband camera, MCAP, on board the spacecraft are going to observe the surface of the celestial body during the flyby.

    JAXA is responsible for the development, construction and launch of the spacecraft and the subsequent operation of the mission. The German DDA instrument is being developed under the leadership of the Institute of Space Systems (IRS) at the University of Stuttgart (DE) in cooperation with the company von Hoerner & Sulger GmbH (DE). DDA is supported by the DLR Space Administration with funds from the German Federal Ministry of Economic Affairs and Energy (Bundesministerium für Wirtschaft und Energie; BMWi).

    Contract signed as part of the DLR-JAXA Strategy Dialogue meeting

    The German-Japanese cooperation agreement for the DESTINY+ mission was signed during the recent DLR/JAXA Strategy Dialogue annual meeting, which was attended by Anke Kaysser-Pyzalla, Chair of the DLR Executive Board, Walther Pelzer, DLR Executive Board Member and Head of the DLR Space Administration, and Hansjörg Dittus, DLR Executive Board Member for Space Research and Technology. The online conference covered the entire spectrum of the now more than 60 joint collaborations with a view to stepping up the successful cooperation. In February 2016, DLR and JAXA signed a comprehensive joint strategy agreement in Tokyo.

    The aim of both partners is to coordinate their aerospace programmes more closely and to combine their expertise. An important topic in this context is the exploration of the Solar System. For example, together with French partners, DLR developed the asteroid lander MASCOT, which landed on asteroid Ryugu in autumn 2018 as part of JAXA’s Hayabusa2 mission. The landing of a JAXA capsule in Australia containing samples from Ryugu is expected on 6 December 2020. In the future, DLR and JAXA will work together on the MMX mission to explore the Martian moons, Phobos and Deimos. In addition, Germany and Japan make extensive use of the International Space Station (ISS) to address questions in the fields of medicine, materials development and basic research.

    See the full article here .

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    DLR Center

    DLR DE is the national aeronautics and space research centre of the Federal Republic of Germany. Its extensive research and development work in aeronautics, space, energy, transport and security is integrated into national and international cooperative ventures. In addition to its own research, as Germany’s space agency, DLR has been given responsibility by the federal government for the planning and implementation of the German space programme. DLR is also the umbrella organisation for the nation’s largest project management agency.

    DLR (DE) has approximately 8000 employees at 16 locations in Germany: Cologne (headquarters), Augsburg, Berlin, Bonn, Braunschweig, Bremen, Goettingen, Hamburg, Juelich, Lampoldshausen, Neustrelitz, Oberpfaffenhofen, Stade, Stuttgart, Trauen, and Weilheim. DLR also has offices in Brussels (BE) , Paris (FR), Tokyo (JP) and Washington D.C. (US).

     
  • richardmitnick 11:04 am on November 6, 2020 Permalink | Reply
    Tags: "Hubble telescope reveals asteroid Psyche’s rusty surface", Asteroids, , , , , ,   

    From NASA/ESA Hubble Telescope via EarthSky: “Hubble telescope reveals asteroid Psyche’s rusty surface” 

    NASA/ESA Hubble Telescope


    From NASA/ESA Hubble Telescope

    via

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    EarthSky

    November 6, 2020
    Amy Oliver

    Scientists already had Psyche classified as a metallic asteroid, but new observations with the Hubble telescope reveal its rusty surface and provide scientists with a unique view into what Earth-like planets are like during their formation.

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    This giant asteroid made of metal could offer a glimpse of what lies deep in the heart of our own planet. A massive asteroid located 230 million miles (370 million km) away from Earth. New ultraviolet observations of the asteroid and its surface revealed that it may be made entirely of nickel and iron, making it the perfect candidate to tell the tale of how Earth-like planets are formed [NASA/JPL Caltech]. It is thought to be the core of a failed planet formation. Credit: Arizona State University.

    A team of scientists led by Tracy Becker of the Southwest Research Institute in San Antonio, Texas, said on October 26, 2020, that the deepest-ever ultraviolet observations of the asteroid 16 Psyche have revealed a secret: the asteroid may be made entirely of iron and nickel, and its surface may be covered in rust. Psyche was already classified as an M-type asteroid, that is, an asteroid known to contain a significant percentage of metal. It’s one of the most massive objects currently known to be orbiting in the solar system’s asteroid belt between Mars and Jupiter. Generally speaking, metal asteroids are rare, and the study revealed that Psyche may be the most “metal-like” of all known asteroids. Thus Psyche has a story to tell about solid planets like Earth and what happened when they were forming 4 1/2 billion years ago.

    These scientists’ paper is slated for publication in the December 2020 issue of the peer-reviewed Planetary Science Journal.

    At 140 miles (225 km) in diameter, Psyche spans roughly the distance between Philadelphia and Washington, D.C., and provides plenty of surface for scientists to observe and study. New ultraviolet (UV) observations of the massive asteroid have revealed that Psyche’s surface may be mostly made of iron, but scientists believe further study is required to confirm their findings, as lab models provided conflicting outcomes.

    Becker, a planetary scientist at the Southwest Research Institute, is the lead author on the paper. She told EarthSky:

    “The way that Psyche reflects UV light is very similar to the way iron and metallic meteorites reflect UV light; the UV spectrum of Psyche is similar to that of iron. But we note that in our computer models, we found we could reproduce the spectrum of Psyche with as little as 10% of iron mixed into other materials. So, we can’t conclude definitively just how much iron is on the surface, but it does look like some metals are there.”

    Scientists also found another way to detect iron on the surface: by looking for rust. After all, where there is iron, there may be rust, or something similar. To find it, Becker’s team focused their efforts on hunting for spectral evidence of iron oxide, which is typically observed on Earth and other bodies as rust. The scientists needed a way to ferret out iron oxide signatures. While unable to scoop up a sample from 230 million miles (370 million km) away, ultraviolet (UV) observations provided the solution. UV light is made up of short wavelengths that are invisible to the human eye but carry high energy, and are capable of damaging living tissue and causing sunburns and skin cancer. But in astronomy, these short wavelengths of light are beneficial and can help scientists understand chemical composition, density, and temperature. For these researchers, UV light was the key to help unveil iron oxide on the surface of Psyche.

    Becker said:

    “Recent laboratory work shows that you can see the iron oxide signatures in the UV better than at other wavelengths, so we wanted to look for those. The UV is also very sensitive to the uppermost layer of the planetary body, so we would be able to see how much of the asteroid’s surface has been [changed over time]”.

    Becker’s team engaged in patient observation of Psyche, taking UV measurements on both sides of the asteroid to get a complete picture of its surface. The team’s patience paid off when they saw evidence of iron oxide. Becker said in a statement:

    “We were able to identify, for the first time on any asteroid, what we think are iron oxide ultraviolet absorption bands. This is an indication that oxidation is happening on the asteroid, which could be a result of the solar wind hitting the surface.”

    Although this is the first time that scientists have observed evidence of iron oxide on an asteroid, it isn’t the first time that rust has been observed in our solar system. Mars – often referred to as the red planet due to its hue – is covered in rust particles, which are blown around on the planet as winds shape its surface. And while the appearance of rust on Psyche doesn’t necessarily mean that the asteroid is corroding, scientists did detect evidence of surface changes.

    During observations, Becker’s team noticed that Psyche’s uppermost layers appeared more reflective at deeper UV wavelengths. While Becker said this phenomenon requires further study, she noted that the observed brightening may be the result of further space weathering. She said:

    “All planetary bodies are exposed to space weathering by the sun, and other processing through small impacts by micrometeorites, that will change their surfaces. Characterizing space weathering is helpful for understanding how long the surface has been exposed to space.”

    Becker’s team carried out UV emission observations on Psyche using the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST). Before the study, no other previous UV observations of Psyche had been made, in part due to the difficulty of conducting studies using UV light. Becker said:

    “We cannot observe any objects in the ultraviolet from ground-based telescopes, since our atmosphere blocks UV light. The only way to observe solar system objects in the UV is with space-based telescopes, which are limited. Psyche hadn’t been observed at these wavelengths – mid- and far-UV – of light before. There had been near-UV observations from the International Ultraviolet Explorer (IUE), but these HST observations go farther in the UV than ever before.”

    Before the new study, scientists already believed Psyche to be the leftover core of a protoplanet that never finished forming. The new observations, and the discovery of iron oxide signatures, have revealed the asteroid to be truly unique, and even more Earth-like than previously believed. Becker said:

    “We’ve seen meteorites that are mostly metal, but Psyche could be unique in that it might be an asteroid that is completely made of iron and nickel. Earth has a metal core, a mantle and a crust. It’s possible that as a Psyche protoplanet was forming, it was struck by another object in our solar system and lost its mantle and crust.”

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    NASA’s Psyche mission will launch toward the asteroid of the same name in 2022. Scientists hypothesize that this asteroid is actually the leftovers of a failed planet formation. New ultraviolet studies with Hubble have shown that Psyche is even more unique than that, as it may consist entirely of nickel and iron, and that the iron may be rusting. Image via NASA/ JPL-Caltech.

    The leftovers from this stellar hit-and-run have long sparked interest in Psyche. In 2017, NASA announced a mission to the asteroid, which will be the first such mission to an object not made of rock or ice. Set to launch in 2022, NASA’s orbiter will reach Psyche in 2026, and either confirm or deny scientists’ observations and theories. No matter the outcome, Becker is looking forward to seeing what secrets the mission will reveal. She said:

    “What makes Psyche and the other asteroids so interesting is that they’re considered to be the building blocks of the solar system. To understand what really makes up a planet and to potentially see the inside of a planet is fascinating. Once we get to Pysche, we’re finally going to understand if that’s the case, even if it doesn’t turn out as we expect. Any time there’s a surprise, it’s always exciting.”

    See the full article here .


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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 9:35 am on November 2, 2020 Permalink | Reply
    Tags: "What is it with all that dust?", Asteroids, , , , , , , If white dwarfs should have cleared out all of this debris during the red giant phase then why do some of them seem to have closely orbiting dusty debris discs?, LSPM J0207+3331 – the oldest and coldest white dwarf known   

    From COSMOS(AU): “What is it with all that dust?” 

    Cosmos Magazine bloc

    From COSMOS(AU)

    31 October 2020
    Richard A Lovett

    Scientists solve another mystery about white dwarfs.

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    Artist’s impression of an asteroid is broken apart by LSPM J0207+3331 – the oldest and coldest white dwarf known. The system’s infrared signal is hypothesised to comprise two rings composed of dust supplied by crumbling asteroids. Credit: NASA’s Goddard Space Flight Centre / Scott Wiessinger.

    Scientists studying how comets and asteroids break up and vaporize if they get too close to their suns have resolved a conundrum about a class of stars known as white dwarfs.

    Embers of dying suns, white dwarfs form when a star, having run out of its nuclear fuel, first expands to enormous size then collapses into a dense, Earth-sized remnant.

    The initial, swollen size is called a red giant – and is large enough to consume planets as far out as Earth, and even Mars. It then implodes, leaving the white dwarf, which can initially be as hot as 50,000 degrees Celsius, until it gradually cools into obscurity.

    So far, so good. But astronomers have found that about 4% of them appear to be accompanied by clouds of dust.

    “This begs the question, if white dwarfs should have cleared out all of this debris during the red giant phase, then why do some of them seem to have closely orbiting dusty debris discs,” Jordan Steckloff, of the Planetary Science Institute (US), told this week’s virtual meeting of the American Astronomical Society’s Division for Planetary Sciences.

    Previously, he says, it was assumed that these discs were formed from planetesimals or asteroids that were far enough out to survive immolation in the red giant phase, but then fell inward, winding up so deep in the white dwarf’s gravity that they got ripped to shreds—something that occurs at a distance often referred to as the Roche limit.

    These shreds would then be dispersed into a “nice tight dusty debris disc” by the pressure of the light emitted by the star.

    But there was a big problem with that theory. One would expect younger white dwarfs to have less stable planetary systems, thanks to the gravitational mayhem that accompanied the effect of the red giant destroying all of the inner planets. In other words, they should have more worldlets falling toward the star to be ripped into dust.

    Also, younger white dwarfs are hotter – and therefore brighter – and should be better at making dusty discs out of the debris of shredded planetesimals.

    But that, Steckloff says, is not what astronomers have seen. Young super-hot white dwarfs do not have dust disks. “It’s only when white dwarfs cool to less than about 27,000 degrees Kelvin (27,000°C) that we actually see dusty debris discs start to appear.”

    The answer, he says, is something fairly obvious (in hindsight) but previously overlooked: if a planetesimal falls too close to a super-hot star, not only will it get shredded into dust, that dust will then be vaporized by the heat – a process he refers to as sublimation. The result: no dusty disc.

    “It needs to be outside the sublimation limit and inside the Roche limit,” he says.

    The Roche limit is determined by the star’s mass, but the sublimation limit is determined by its brightness, which declines as it cools.

    And, he says, it turns out that for young, super-hot white dwarfs, the Roche limit is inside the sublimation limit. I.e., anything that falls close enough to the star to be shredded will also be vaporized.

    It is only when the white dwarf cools to somewhere between 25,000 and 32,000 Celsius, he says, that this reverses – with the exact temperature depending on what type of minerals the dust is composed of. In fact, the figure comes even closer to 27,000 degrees if it is assumed that the dust in these discs is similar to the materials in our own Solar System’s asteroids.

    And that might be one of his most important findings.

    “The 27,000-degree limit suggests that the material that we find orbiting around white dwarfs is likely analogous to [asteroids] in our own Solar System,” he says.

    See the full article here .


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  • richardmitnick 9:39 am on September 16, 2020 Permalink | Reply
    Tags: "ESA’s Hera planetary defense mission signs prime contractor on course for launch in 2024", Asteroids, DART will carry with it an Italian-provided CubeSat called LICIACube (Light Italian CubeSat for Imaging of Asteroids)., DART will carry with it an Italian-provided CubeSat called LICIACube., LICIACube will collect images of the impact and ejecta and transmit its captured photographs back to Earth., , , The Didymos pair- a binary asteroid   

    From NASA Spaceflight: “ESA’s Hera planetary defense mission signs prime contractor, on course for launch in 2024” 

    NASA Spaceflight

    From NASA Spaceflight

    September 15, 2020
    Chris Gebhardt

    1
    The European Space Agency (ESA) has signed a design, manufacturing, and testing contract with OHB of Germany for their Hera planetary defense mission, marking a major advancement toward the agency’s commitment to NASA for their joint Asteroid Impact and Deflection Assessment project.

    NASA’s portion [DART] is scheduled to launch in July 2021 and slam into the smaller of the target binary asteroid in October 2022.

    NASA DART Double Impact Redirection Test vehicle depiction schematic.

    Hera will then follow, launching in 2024 on an Ariane 6 and arriving at the binary pair in 2027 to assess how well its predecessor did in changing the orbit of its target.

    The contract signed today between ESA and OBH of Germany provides €129.4 million for a detailed design, build, and test of the Hera asteroid orbiter. The contract specifically includes the new and advanced Guidance, Navigation and Control system for the craft.

    Excluded from the OBH contract are the other deals already in place for the two CubeSats that will accompany Hera to the target binary asteroid and the long-lead technology items for the mission — contracts that are already underway.

    Unlike the first part of the joint Asteroid Impact and Deflection Assessment project from NASA, an impactor called DART, Hera will not impact either of the bodies of the target but rather perform long-term observations from a close orbit while demonstrating new technologies, particularly for autonomous deep space proximity operations.

    The target for the joint mission is the Didymos pair, a binary asteroid whose primary is 780 m in diameter and whose moonlet (small moon) is 160 m in diameter.

    The moonlet, called Dimorphos, is the target of NASA’s DART kinetic impactor.


    The Double Asteroid Redirection Test (DART): Hitting an Asteroid Head On. DART (Double Asteroid Redirection Test) is scheduled to launch no earlier than 22 July 2021 from Vandenberg Air Force Base, California, atop a SpaceX Falcon 9 rocket.

    Powered by a NEXT ion thruster, the 500 kg (1,100 lb) spacecraft will spend 15 months cruising to its destination before slamming into Dimorphos at 6.25 km/s.

    DART carries no scientific instruments, just a star tracker and camera for autonomous navigation; it is simply an impactor. It will, however, carry with it an Italian-provided CubeSat called LICIACube (Light Italian CubeSat for Imaging of Asteroids) that will deploy shortly before observing the ejecta cloud thrown up from the impact.

    LICIACube will collect images of the impact and ejecta and transmit its captured photographs back to Earth; it was offered to DART by the Italian Space Agency after ESA’s first spacecraft contribution to the mission was cancelled in 2016.

    That project, the Asteroid Impact Mission, would have worked in tandem with DART, observing the other craft’s impact while providing immediate and long-term assessments of changes to Dimorphos’ orbit and characteristics while studying the ejecta material.

    2
    Hera inspects DART’s impact crater. Credit ESA.

    While Hera will not be able to do that first part, most of the Asteroid Impact Mission’s objectives can be accomplished with LICIACube and Hera’s long-term in situ observations that can begin upon its arrival in 2027.

    The overall mission will test whether or not a kinetic impactor can successfully deflect potentially hazardous Earth-bound asteroids by slightly changing their orbital speed to either slow them down slightly or accelerate them slightly.

    A minor velocity change imparted to a large asteroid could — over the course of months or years — alter its orbit safely away from intersecting with Earth.

    And this is exactly what NASA and ESA seek to do on a smaller scale in the Didymos pair system. The DART spacecraft, while impacting Dimorphos at 6.25 km/s will only produce a net change in the moonlet’s velocity of 0.4 millimeters per second.

    While that is an incredibly small change in velocity, it will radically change the mutual orbit of the Didymos primary and its moon.

    As such, the interagency mission represents the first time humanity will intentionally alter another celestial body’s orbit.

    By impacting the smaller of the two bodies, which orbits the larger, NASA and ESA can safely observe how a kinetic impactor alters orbital characteristics of an asteroid.


    Hera: Our planetary defense mission.

    The Didymos pair’s overall orbit of the Sun is also extremely favorable to this type of test as its orbit does not cross that of Earth’s — meaning there’s no chance the NASA-ESA experiment could accidentally cause this pair to pose a threat to our host planet.

    When Hera then arrives in 2027, it will find a very different system than the DART spacecraft encountered while on approach for impact.

    Hera will use a suite of scientific instruments as well as two ride along CubeSats (which will attempt to land on the surface of Dimorphos) to characterize exactly how much momentum was transferred between the two objects at DART’s impact and exactly how much Dimorphos’ orbit was altered.

    This will “allow, for the first time, the validation or refinement of numerical models of the impact process at asteroid scale, rendering this deflection technique for planetary defence ready for operational use if ever needed to safeguard our home world,” notes an ESA overview of the mission.

    Hera will accomplish its scientific objectives by utilizing:

    an Asteroid Framing Camera provided by Germany (that is actually a spare unit for NASA’s Dawn spacecraft in the asteroid belt),
    a compact laser radar, or lidar, for surface mapping operations,
    a thermal infrared instrument to survey the asteroid in the mid-infrared spectral range and map temperature dispersions across Dimorphos’ surface, and
    a radio science experiment to measure the mass and mass distribution within the moon.

    These instruments will be supplemented by those carried aboard the two CubeSats, which will use radar to investigate the interior of the moonlet as well as imaging and mass spectrometers to study its mineralogical and elemental composition.

    See the full article here .

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    NASA Spaceflight , now in its eighth year of operations, is already the leading online news resource for everyone interested in space flight specific news, supplying our readership with the latest news, around the clock, with editors covering all the leading space faring nations.

    Breaking more exclusive space flight related news stories than any other site in its field, NASASpaceFlight.com is dedicated to expanding the public’s awareness and respect for the space flight industry, which in turn is reflected in the many thousands of space industry visitors to the site, ranging from NASA to Lockheed Martin, Boeing, United Space Alliance and commercial space flight arena.

    With a monthly readership of 500,000 visitors and growing, the site’s expansion has already seen articles being referenced and linked by major news networks such as MSNBC, CBS, The New York Times, Popular Science, but to name a few.

     
  • richardmitnick 10:59 am on September 8, 2020 Permalink | Reply
    Tags: "Grains of dust revise Solar System history", Asteroids, Asteroids like Vesta formed in the inner Solar System are built of materials with a different array of chemical isotopes than those from asteroids which formed farther out in the Solar System., , , , Carbonaceous chondrite meteorites, , , Such meteorites are chips off asteroids that have been blasted into space by collisions only to eventually fall to Earth where they can be examined in laboratories.,   

    From UC Davis via COSMOS: “Grains of dust revise Solar System history” 

    UC Davis bloc

    From UC Davis

    via

    Cosmos Magazine bloc

    COSMOS

    8 September 2020
    Richard A Lovett

    Scientists study the chemical composition of meteorites.

    1
    Credit: Science Photo Library – andrzej/Getty Images.

    Asteroids that formed far out in the Solar System appear to contain dust grains that themselves condensed from the infant Solar System’s protoplanetary disc much closer to the Sun, scientists say.

    That means this dust was somehow transported from the inner reaches of the disc to its outer reaches, says Curtis Williams, a geochemist at the University of California, Davis. Once there, it mixed with material that condensed from that part of the disc to form larger objects that eventually became asteroids.

    In a study described in the journal PNAS, Williams and a team of US and Japanese researchers found these dust grains in a type of meteorite known as carbonaceous chondrites.

    Such meteorites are chips off asteroids that have been blasted into space by collisions, only to eventually fall to Earth, where they can be examined in laboratories.

    Previous studies had found that rocks from Earth and Mars, as well as asteroids like Vesta, which formed in the inner Solar System, are built of materials with a different array of chemical isotopes than those from asteroids known to have formed farther out in the Solar System.

    Based on that, scientists had assumed that inner Solar System dust – which is different from outer Solar System dust because it condensed in hotter regions closer to the Sun – did not mix with outer Solar System dust. Instead, they assumed, it remained relatively close to the Sun.

    The reason for this separation, they assumed, was the formation of the giant planet Jupiter, whose enormous gravity created a gap through which dust could not migrate. This, they assumed, divided the young Solar System into two distinct parts.

    In the new study, however, Williams’s team delved into 30 carbonaceous chondrites and looked at their individual components. “They have microcomponents, called inclusions,” Williams says.

    Looking carefully at isotopes in these sand-grain-sized inclusions, he says, his team found that some formed in the outer Solar System, but some must have formed closer to the Sun, then migrated outward before accreting into a larger body.

    Since Jupiter is believed to have already been present at the time these grains dispersed, Williams says, “that has big implications. Either Jupiter was not a complete barrier, or these particles somehow jumped over Jupiter and landed in the outer Solar System.”

    It’s an important finding partly because it will help planet-formation modellers better understand how dust grains migrate around a protoplanetary disk – including one in which giant planets are forming – before being incorporated into larger objects.

    But it will also help modellers figure out important aspects of conditions in these protoplanetary discs, including the viscosity and turbulence of their gas and dust.

    “That plays a role in how you build planets,” Williams says.

    See the full article here .

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    UC Davis Campus

    The University of California, Davis, is a major public research university located in Davis, California, just west of Sacramento. It encompasses 5,300 acres of land, making it the second largest UC campus in terms of land ownership, after UC Merced.

     
  • richardmitnick 7:55 am on June 23, 2020 Permalink | Reply
    Tags: "ESA highlights protection for our planet ahead of Asteroid Day", Asteroids, , , , ,   

    From European Space Agency – United Space in Europe: “ESA highlights protection for our planet ahead of Asteroid Day” 

    ESA Space For Europe Banner

    From European Space Agency – United Space in Europe

    ESA / Safety & Security

    The United Nations’ International Asteroid Day on 30 June highlights ESA’s expanding efforts to secure our future by understanding and addressing risks posed by near-Earth objects that could impact our planet.

    “The work of ESA and the international planetary defence community is a great example of how to address this important hazard,” says ESA Director General Jan Wörner. “An asteroid impact is the only natural disaster we might avoid, if we see one coming soon enough.”

    1
    Hera at Didymos. ESA’s Hera asteroid mission approaching the smaller of the two Didymos asteroids to map the impact crater left by NASA’s DART spacecraft.

    ESA’s proposed Hera spaceraft depiction

    NASA DART Double Impact Redirection Test vehicle depiction schematic

    “Even when the threat is low, governments and international organisations such as the UN working together show that it is possible to get ready in advance and mitigate damage from a global threat that can affect anyone, anywhere.”

    Current ESA activities include:

    -Detailed design work is proceeding on ESA’s first planetary defence validation mission: the Hera spacecraft will fly to the Didymos asteroid pair in 2024, following on from NASA’s DART mission due to be launched next year, which will deflect the smaller asteroid.

    -ESA’s long-running asteroid observations have resumed, following a brief pause due to the Covid-19 pandemic. Near-Earth asteroids are identified and tracked from various telescopes across Europe and the world.

    -ESA’s Near-Earth Object (NEO) Coordination Centre in Italy continues to coordinate asteroid observations and assess risks from newly discovered objects, despite the serious Covid-19 effects in that country.

    -The first of ESA’s new multi-optic ‘Flyeye’ telescopes is under construction near Milan, and will facilitate the automated detection of asteroids once in operation.

    ESA Flyeye telescope

    -ESA’s deep-space ground stations have contributed communication coverage for Japan’s Hayabusa2 mission, which is now headed Earthward after collecting samples from an asteroid.

    JAXA Hayabusa2

    -ESA is sponsoring a Grand Challenge on In-Situ Resource Utilisation for the Moon and asteroids, allowing future explorers to make use of materials found in space. Temporarily suspended due to the Covid-19 pandemic, this €500 000 competition is set to resume soon.

    -The Agency’s suitcase-sized ‘Miniature Asteroid Remote Geophysical Observer’ (M-Argo) spacecraft is about to undergo its Preliminary Requirements Review, where experts will declare this audacious mission feasible.ESA’s Comet Interceptor mission, planned to launch near the end of this decade, will wait in space for a suitable body — potentially even an interstellar comet — to investigate.

    3
    ESA M-Argo spacecraft depiction

    ESA and Space Safety

    Under the Agency’s Space Safety Programme, which received an important boost in funding at the Space19+ Ministerial Council in November 2019, ESA is taking action as part of an international effort to mitigate asteroid risks.

    ESA’s goal is to coordinate Europe’s part of a global planetary defence effort, aimed at detecting, studying and following asteroids, predicting if and when they might hit and taking mitigation action if needed.

    UN Asteroid Day

    On 30 June 1908, the Tunguska impact felled many millions of trees across 2200 sq km of Siberian territory, only a few hours of Earth rotation away from Europe – the results would have been disastrous over a populated area.

    Asteroid Day, a UN-endorsed awareness campaign day to mark this historic date, was co-founded by astrophysicist and famed musician Dr Brian May of the rock group Queen, Apollo 9 astronaut Rusty Schweickart, filmmaker Grig Richters, and B612 President Danica Remy.

    Asteroid Day TV supported by ESA

    This year, activities to mark Asteroid Day are moving entirely online, and include a month of Asteroid Day TV distributed by the Luxembourg-based Asteroid Foundation and including programming by ESA as well as top content makers including Discovery Science, TED, IMAX, BBC, CNN, ESO and other educational producers.

    Asteroid Day TV will distribute Asteroid Day LIVE from Luxembourg starting 30 June at 12:00 CEST including five hours of ESA and Asteroid Day programme segments newly produced for 2020 in English.

    ESA is also planning new programme segments in Dutch, French, German, Italian and Spanish. These will premiere in advance of 30 June.

    All segments will be broad- and webcast to the public via AsteroidDay.org, via SES Satellite and to other broadcasters via satellite and digital CDN via RTL’s Broadcasting Center Europe (BCE).

    Segments will also be available via ESA Web TV and ESA’s YouTube channel.

    3
    ESA Space Safety & Security. As we discover more about the brilliant scale and nature of the Universe, planet Earth’s blue oceans, green forests and glistening city lights appear even more unique, and even more fragile. Many hazards have been identified originating in space, which although unlikely, continue to pose real dangers to our way of life, and in the worst cases to human health and safety. Only in the past decades have we had the opportunity to understand the potential perils of our position in our Solar System, and as technologies continue to advance we are entering a period in which we can actually act. However, as technologies advance, so too does our dependence on them, making us more vulnerable to both human-made and natural threats in space. ESA’s Space Situational Awareness (SSA) programme was launched in 2009, with the aim of ensuring that Europe can independently detect, predict and assess threats from space and their potential risk to life, property and infrastructure.

    ESA programming schedule

    ESA’s Asteroid Day 2020 dedicated-language segments will premiere in Asteroid Day TV (followed by frequent replay until 4 July) as follows:

    Italian 24 June 17:00-18:00 CEST

    German 25 June 17:00-18:00 CEST

    French 25 June 18:30-19:30 CEST

    Dutch 26 June 11:00-12:00 CEST

    Spanish 26 June 17:00-18:00 CEST

    English 30 June 12:00-13:00 CEST and 18:00-19:00 CEST

    More information and full broadcast schedule via https://asteroidday.org/broadcast-schedule/

    See the full article here .


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    The European Space Agency (ESA), 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 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.

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  • richardmitnick 12:29 pm on June 20, 2020 Permalink | Reply
    Tags: "Exploring Links Between Nearby Asteroids", 3200 Phaethon and (155140) 2005 UD- are they linked?, , Asteroids, , , ,   

    From AAS NOVA: “Exploring Links Between Nearby Asteroids” 

    AASNOVA

    From AAS NOVA

    19 June 2020
    Susanna Kohler

    1
    Artist’s illustration of the near-Earth asteroid 3200 Phaethon, one target of an upcoming fly-by mission. [Heather Roper/University of Arizona]

    It’s not easy being a speeding rock in our solar system.

    2
    Illustration of an asteroid breaking apart into smaller fragments. [NASA/JPL]

    Over their lifetimes, the millions of minor rocky bodies of our solar system — asteroids — are subject to extreme conditions. Some experience dramatic collisions, some are spun up to such high rotation speeds that they fly apart, and some venture so close to the Sun that our star’s heat cracks them into pieces.

    Over time, these violent processes create families of asteroids that dance around our solar system on similar paths. Where one rock once orbited, there might now be a group of genetically linked asteroids that follow similar trajectories — all produced by the splitting of one parent rock.

    In a new study, scientists have explored two especially nearby asteroids to determine whether they might be linked.

    A Visit to a “Potentially Hazardous” Neighbor

    3
    The orbital path of the near-Earth asteroid Phaethon. [Sky&Tel]

    Asteroids whose orbits bring them close to the Earth are of particular interest to us: we like to keep an eye on those bodies that might threaten our planet.

    Perhaps 22,000 near-Earth asteroids are currently known, with just over 2,000 that are large enough and swing close enough to Earth’s orbit to be considered “potentially hazardous” — though it should be noted that the vast majority of these have been ruled out as being an impact threat in at least the next 100 years.

    4
    Artist’s illustration of the DESTINY+ spacecraft. [JAXA]

    To learn more about these nearby bodies, the Japanese Aerospace Exploration Agency is sending a spacecraft, DESTINY+, to fly by a large (~5-km) near-Earth asteroid. The target is 3200 Phaethon — an unusual blue-toned, dust-producing asteroid thought to be the source of the Geminid meteor stream — and other minor bodies that might be associated with it.

    As DESTINY+ is currently scheduled to launch in 2022, scientists are currently preparing by learning all they can about the possible mission targets using ground- and space-based observatories. In a new study led by Maxime Devogèle (Lowell Observatory), a team of scientists presents detailed observations of (155140) 2005 UD, another near-Earth object and potential DESTINY+ target that might be related to Phaethon.

    Signs Point to a Linked Pair

    Devogèle and collaborators gathered an impressive array of observations of 2005 UD, using dozens of telescopes to obtain photometry, polarimetry, and spectroscopy, and also reanalyzing thermal imaging.

    5
    2005 UD and Phaethon exhibit very similar spectra, including rare spectroscopic (B-type) signatures. [Devogèle et al. 2020]

    By combining new observations with archival data and detailed modeling, the team constrained 2005 UD’s size (just over 1 km across) and rotation rate (it spins roughly once every 5.2 hours), as well as many other properties like its albedo, spectroscopic class, and even the size of the grains on its surface — knowledge that will all help with mission planning for DESTINY+.

    But what about 2005 UD’s potential link to Phaethon? Based on Devogèle and collaborators’ observations, 2005 UD and Phaethon appear to share more than just orbital characteristics. They also have very similar — and rare, among asteroids — physical properties as shown by their spectroscopy and polarimetry.

    More study is needed, but the data suggest that the two are, indeed, genetically linked — perhaps 2005 UD and Phaethon both split from the same parent thousands of years ago. With any luck, DESTINY+ will soon reveal more about these close-swinging rocky bodies!

    Citation

    “New Evidence for a Physical Link between Asteroids (155140) 2005 UD and (3200) Phaethon,” Maxime Devogèle et al 2020 Planet. Sci. J. 1 15.
    https://iopscience.iop.org/article/10.3847/PSJ/ab8e45

    See the full article here .


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    1

    AAS Mission and Vision Statement

    The mission of the American Astronomical Society is to enhance and share humanity’s scientific understanding of the Universe.

    The Society, through its publications, disseminates and archives the results of astronomical research. The Society also communicates and explains our understanding of the universe to the public.
    The Society facilitates and strengthens the interactions among members through professional meetings and other means. The Society supports member divisions representing specialized research and astronomical interests.
    The Society represents the goals of its community of members to the nation and the world. The Society also works with other scientific and educational societies to promote the advancement of science.
    The Society, through its members, trains, mentors and supports the next generation of astronomers. The Society supports and promotes increased participation of historically underrepresented groups in astronomy.
    The Society assists its members to develop their skills in the fields of education and public outreach at all levels. The Society promotes broad interest in astronomy, which enhances science literacy and leads many to careers in science and engineering.

    Adopted June 7, 2009

     
  • richardmitnick 10:05 am on March 30, 2020 Permalink | Reply
    Tags: Asteroids, , NASA's DART (Double Asteroid Redirection Test) mission, NASA's Evolutionary Xenon Thruster – Commercial (NEXT-C), NEXT-C is a powerful engine. It's nothing like a rocket which requires a massive amount of thrust to lift something away from Earth's gravity., , The Italian Space Agency is providing LICIA (Light Italian CubeSat for Imaging of Asteroids) for the mission., This Epic Ion Engine Will Power NASA's Test Mission to Redirect an Asteroid, Tiny binary asteroid system called Didymos   

    From Science Alert: “This Epic Ion Engine Will Power NASA’s Test Mission to Redirect an Asteroid” 

    ScienceAlert

    From Science Alert

    29 MARCH 2020
    EVAN GOUGH

    1
    (NASA/Bridget Caswell)

    Despite humanity’s current struggle against the novel coronavirus, and despite it taking up most of our attention, other threats still exist. The very real threat of a possible asteroid strike on Earth in the future is taking a backseat for now, but it’s still there.

    Though an asteroid strike seems kind of ephemeral right now, it’s a real threat, and one that has the potential to end humanity. Agencies like NASA and the ESA are still working on their plans to protect us from that threat.

    NASA’s DART (Double Asteroid Redirection Test) mission is scheduled to launch on 22 July 2021.

    NASA DART Double Impact Redirection Test vehicle depiction schematic

    It’s a demonstration mission to study the use of kinetic impact to deflect an asteroid. It’ll head for the tiny binary asteroid system called Didymos, (or 65803 Didymos.) This double asteroid system poses no threat to Earth.

    The larger of the pair, named Didymos A, is about 780 meters (2560 ft.) in diameter, while the smaller one, Didymos B, is only about 160 meters (535 feet) DART will crash itself into the Didymos B. It’s close to the typical size of an asteroid that threatens Earth.

    2
    A simulated image of the Didymos binary asteroid. (Naidu et al., AIDA Workshop, 2016)

    DART has a lot of space to cover to reach Didymos. After launching in July 2021, it will reach its target in September 22, when the binary asteroid is within 11 million km (6.8 million miles) of Earth. And to get there, it’ll rely on a powerful ion engine called NASA’s Evolutionary Xenon Thruster – Commercial (NEXT-C).

    The engine comes in two primary components: the thruster and the power processing unit (PPU.) NEXT-C is getting ready for the mission with a series of tests, both performance and environmental.

    The thruster was put through vibration, thermal vacuum and performance tests before being integrated with its PPU. It was also subjected to simulated spaceflight conditions: the extreme vibration during launch, and the extreme cold of space.

    3
    The power processing unit of the thruster is removed from another vacuum chamber after successful testing. (NASA/Bridget Caswell)

    NEXT-C is a powerful engine. It’s nothing like a rocket, which requires a massive amount of thrust to lift something away from Earth’s gravity. But in terms of ion drives, it’s a very powerful unit. It’s about three times more powerful than the NSTAR ion drives on NASA’s DAWN and Deep Space One spacecraft.

    NASA/DLR Dawn Spacecraft (2007-2018)

    3
    Deep Space One spacecraft. Wikipedia

    NEXT can produce 6.9 kW thrust power and 236 mN thrust. The engine has produced the highest total impulse of any ion engine: 17 MN·s. It also has a specific impulse, which is a measure of how efficiently it uses propellant, of 4,190 seconds, compared to NSTAR’s 3,120.

    Ion drives don’t burn fuel like a rocket, though they do use a propellant. Typically the propellant is xenon, like in NEXT-C. The NEXT-C ion engine is a double-grid system.

    The xenon is fed into a chamber, where it encounters the first, or upstream, grid. Solar arrays provide the electricity, and the first grid is charged positive. As the xenon ions pass through the upstream grid, they are charged positively.

    This draws them toward the second or accelerator grid, which is charged negatively. This propels them out of the engine, providing thrust. The thrust is equal to the force between the upstream ions and the accelerator grid.

    4
    NASA Evolutionary Xenon Thruster being tested in a vacuum chamber. (NASA)

    When DART reaches the Didymos binary asteroid, it will have some company. The Italian Space Agency is providing LICIA (Light Italian CubeSat for Imaging of Asteroids) for the mission.

    6
    https://www.nanosats.eu/sat/liciacube

    LICIA is 6 cubesats that will separate from DART prior to impact with Didymos B. It’ll capture images of the impact and the debris ejected from the collision and transmit it back to Earth.

    The impact is expected to change Didymos B’s orbital velocity by about a half millimeter per second. That will change its rotation period by a large enough amount that Earth-based telescopes will detect it. It will also leave a crater in the surface, about 20 m (66 ft) wide.

    Though DART will be destroyed when it impacts, the ESA is planning a follow-up mission. It’s called Hera, and it’s scheduled to launch in 2024, and to arrive in 2027.

    ESA’s proposed Hera spaceraft depiction

    Hera will investigate not only the effect of DART’s impact, but will carry a suite of instruments to learn more about binary asteroids, and the interior of the asteroid.

    See the full article here .


    five-ways-keep-your-child-safe-school-shootings

    Please help promote STEM in your local schools.

    Stem Education Coalition

     
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