Subscriber CaaC (John)+ Posted May 18, 2021 Author Subscriber Posted May 18, 2021 (edited) Quote Dating the stars: most accurate red giant age yet Scientists identify stars leftover from a cosmic collision. Researchers have successfully dated some of our galaxy’s oldest stars back to a cosmic collision, using data on their oscillations and chemical composition. The team, led by Josefina Montalbán of the University of Birmingham, UK, investigated the age of some red giant stars that were originally part of a satellite dwarf galaxy called Gaia-Enceladus, which collided with the Milky Way 11.5 billion years ago. In their study, published in Nature Astronomy, the researchers surveyed 100 red giant stars and found that the Gaia-Enceladus stars were all similar in age or slightly younger than the other stars that began life in the Milky Way. This builds on the existing theory that the Milky Way had already started making stars before it merged with Gaia-Enceladus. “The chemical composition, location and motion of the stars we can observe today in the Milky Way contain precious information about their origin,” says Montalbán. “As we increase our knowledge of how and when these stars were formed, we can start to better understand how the merger of Gaia-Enceladus with the Milky Way affected the evolution of our Galaxy.” As part of their analysis, they used a technique called asteroseismology, which measures the relative frequency and amplitudes of the natural modes of oscillations of stars. This gives information about the size and internal structure of stars, which then helps estimate star age. They combined this data with spectroscopy – a technique that measures light and radiation produced by matter – to identify the chemical composition of the stars, which also reveals information about age. “We have shown the huge potential of asteroseismology in combination with spectroscopy to deliver precise, accurate relative ages for individual, very old, stars,” says co-author Andrea Miglio of the University of Bologna, Italy. “Taken together, these measurements contribute to sharpen our view on the early years of our Galaxy and promise a bright future for Galactic archeoastronomy.” https://cosmosmagazine.com/space/astronomy/dating-the-stars-most-accurate-red-giant-age-yet/ Edited May 18, 2021 by CaaC (John) 1 Quote
Subscriber CaaC (John)+ Posted May 19, 2021 Author Subscriber Posted May 19, 2021 Quote Inside the mission to spot an alien city by harnessing the Sun’s colossal gravity Astronomers generally view the Sun as an obstacle to the objects they want to study. But it might just be the key that enables them to observe Earth-like exoplanets located many light-years away. A spacecraft hurtles out of the Solar System travelling faster than any rocket, probe or instrument we’ve launched into space before. It’s on a daring mission to answer some of the most fundamental questions about the universe once and for all. “We’ve all been asking them since we were six years old,” says Slava Turyshev from NASA’s Jet Propulsion Laboratory. “Are there other planets? Can we see them? Is there life?” Astronomers have revolutionised our understanding of our place in the Universe over the last quarter of a century. In 1995 they found their first alien planet orbiting a Sun-like star. It whetted their appetites to such a degree that we’ve been hunting them down ever since. At the last count, there are over 4,000 of these exoplanets in our databases. Some of them even appear to have similar traits to Earth – close in both size and temperature. That quickens the pulse and often makes headlines because if life can thrive on our planet, it could be doing the same on an exoplanetary cousin. FULL REPORT 1 Quote
Subscriber CaaC (John)+ Posted May 20, 2021 Author Subscriber Posted May 20, 2021 Quote Heavy metal space rock Scientists unexpectedly find heavy metal vapours in comets both near and far. For the first time, astronomers have detected traces of heavy metals in the atmospheres of comets – both those whizzing through our Solar System and those from interstellar space. Scientists have long known that the dusty, rocky interiors of comets harbour solid forms of heavy metals. But these metals have only previously been observed in hot environments, like evaporating comets soaring too close to the Sun or ultra-hot exoplanet atmospheres. Since these heavy metals don’t usually turn to gas (sublimate) at low temperatures, scientists didn’t expect them in the icy atmospheres of comets. Yet that’s exactly what they found. The results were reported in two separate papers by two separate research teams, both published in Nature. The first study used ESO’s Very Large Telescope (VLT) in Chile to analyse the spectra of comets in our Solar System. When comets get close to the sun, their materials begin to heat up and sublimate, and astronomers can use a technique called spectroscopy to reveal the comet’s chemical composition. The team had been observing comets using ESO’s VLT for 20 years but only just noticed the weak spectral lines signalling the presence of iron and nickel in small amounts. Lead author Jean Manfroid, from the University of Liège in Belgium, says: “It was a big surprise to detect iron and nickel atoms in the atmosphere of all the comets we have observed in the last two decades, about 20 of them, and even in ones far from the Sun in the cold space environment.” The most far-flung comet they analysed was more than 480 million kilometres from the Sun, which is over triple the distance between the Earth and the Sun. The team found iron and nickel in about equal amounts, which is notable because most other material in the Solar System contains ten times more iron than nickel. “We came to the conclusion they might come from a special kind of material on the surface of the comet nucleus, sublimating at a rather low temperature and releasing iron and nickel in about the same proportions,” explains Damien Hutsemékers, also from the University of Liège – though the team is not yet sure what such a material would be. The second Nature study looked further afield to analyse a comet not from our own neck of the woods – but from another Solar System entirely. Another team from Poland spotted a gaseous form of nickel in the icy interstellar comet 2I/Borisov, also using a spectrograph on ESO’s VLT. “At first we had a hard time believing that atomic nickel could really be present in 2I/Borisov that far from the Sun,” says lead author Piotr Guzik from the Jagiellonian University in Poland. 2I/Borisov was just 300 million kilometres from the Sun and had an estimated temperature of 180 degrees Kelvin, much cooler than the 700 degrees Kelvin necessary to sublimate nickel. In their paper, the authors suggest a possible origin: “Unbound nickel atoms seem to originate from the photodissociation of a short-lived nickel-containing molecule that sublimates at low temperatures or is otherwise released with major volatile compounds.” The results show that comets from other star systems have much more in common with comets from our own Solar System than we thought. In an accompanying opinion piece, astronomers Dennis Bodewits and Steven J. Bromley conclude: “If we can unravel the origin of iron and nickel in regular comets and this interstellar object, we might uncover a story of organic chemistry between shared different planetary systems.” The results are also interesting for what they might add to our understanding of the formation of the Solar System, as comets are composed of dust and ice left over from planetary formation. “Comets formed around 4.6 billion years ago, in the very young Solar System, and haven’t changed since that time,” says co-author of the first study, Emmanuel Jehin from the University of Liège. “In that sense, they’re like fossils for astronomers.” https://cosmosmagazine.com/space/astronomy/heavy-metal-space-rock/ Quote
Subscriber CaaC (John)+ Posted May 22, 2021 Author Subscriber Posted May 22, 2021 Quote Watch: NASA instrument captures huge Solar eruption on film The events have the potential to trigger space weather that can interfere with satellites and power grids on Earth. The UK-built Solar Orbiter has recorded its first video showing powerful eruptions from the Sun. These events, known as coronal mass ejections (CMEs), are eruptions near the Sun’s surface that blast out into the Solar System. “Coronal mass ejections can cause geomagnetic storms on Earth, which can disrupt power grids and the satellites we rely on for things like navigation and telephone communications,” said Dr Chris Castelli, director of programmes at the UK Space Agency. “Tracking their progress will provide new insight into how the Sun affects space weather and its impact on our daily lives. “UK specialists are playing a leading role in one of the most important space science missions of our generation through our membership of the European Space Agency.” CMEs can even be dangerous for unprotected astronauts on spacewalks. The video released on Monday came just a few days after a close perihelion pass of the Sun on 10 February, which took the spacecraft within half the distance between Earth and the Sun. The footage shows the CME as captured by Solar Orbiter’s Extreme Ultraviolet Imager instrument, then by the Metis coronagraph, and finally by Solar Orbiter’s Heliospheric Imager (SoloHI). When the footage was captured, the spacecraft was behind the Sun as viewed from Earth, resulting in very low data transfer rates. It has taken more than three months for the data to be downloaded and analysed. sciencefocus.com/news/watch-nasa-instrument-captures-huge-solar-eruption-on-film/ Quote
Subscriber CaaC (John)+ Posted May 23, 2021 Author Subscriber Posted May 23, 2021 (edited) Quote Flower supermoon UK: How to see the largest full Moon of 2021 Find out when you can spot this week's full Moon – and why people in the UK will miss out on a lunar eclipse 'blood Moon'. Good news to all astronomers out there: this May, you’ll be treated to the largest full Moon of 2021, with the Flower supermoon taking to the night sky. Being only 357,462 km away from Earth, the Moon will appear a whole 30 per cent brighter and 14 per cent larger than some previous full Moons. Can you also expect to see a lunar eclipse? If you’re based in Europe, unfortunately not. While Australia and parts of the west Americas will also be able to catch a total lunar eclipse (a so-called ‘Blood Moon’) on 26 May, this event won’t be visible to UK-based stargazers. So, when will we be able to see the Flower Supermoon? And why does it have that brilliant name? All of the answers are orbiting below. If you’re looking for more stargazing tips, be sure to check out our full Moon UK calendar and astronomy for beginners guide. https://www.sciencefocus.com/space/flower-full-supermoon-2021/ Edited May 24, 2021 by CaaC (John) Remove double quote Quote
Subscriber CaaC (John)+ Posted May 24, 2021 Author Subscriber Posted May 24, 2021 Quote This packed image taken with the NASA/ESA Hubble Space Telescope showcases the galaxy cluster ACO S 295, as well as a jostling crowd of background galaxies and foreground stars. Galaxies of all shapes and sizes populate this image, ranging from stately spirals to fuzzy ellipticals. This galactic menagerie boasts a range of orientations and sizes, with spiral galaxies such as the one at the centre of this image appearing almost face on, and some edge-on spiral galaxies visible only as thin slivers of light. The galaxy cluster dominates the centre of this image, both visually and physically. The cluster’s huge mass has gravitationally lensed the light from background galaxies, distorting and smearing their shapes. In addition to providing astronomers with a natural magnifying glass with which to study distant galaxies, gravitational lensing has subtly framed the centre of this image, producing a visually striking scene. Text credit: European Space Agency (ESA) Image credit: ESA/Hubble & NASA, F. Pacaud, D. Coe Media Contact: Claire Andreoli NASA's Goddard Space Flight Center 301-286-1940 Quote
Subscriber CaaC (John)+ Posted May 25, 2021 Author Subscriber Posted May 25, 2021 Quote Our galaxy probably isn’t that special Astronomers look to another galaxy to solve a mystery close to home. Is the Milky Way galaxy typical or special? Australian astronomers have tackled this question by taking a detailed cross-section of a galaxy very similar to our own – and the results suggest we’re more average than we thought. Like many other galaxies, the Milky Way is a spiral galaxy flattened into a disk shape. It actually has two distinct disks: a thin disk, which is the main component containing dust, gas and the bulk of the stars (including our Sun), and a thick disk, which is entirely made up of stars, usually older ones. But not all galaxies have thick disks, and astronomers are still trying to understand how they form. One theory suggests our thick disk formed after a rare and violent accident when a smaller galaxy smashed into ours – but new research suggests a more peaceful evolution. “Our observations indicate that the Milky Way’s thin and thick discs didn’t come about because of a gigantic mash-up, but a sort-of ‘default’ path of galaxy formation and evolution,” says Nicholas Scott, from the ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimensions (ASTRO 3D) and the University of Sydney. “From these results, we think galaxies with the Milky Way’s particular structures and properties could be described as the ‘normal ones.” Scott and his colleague Jesse van de Sande are co-led authors of the new paper published in The Astrophysical Journal Letters. The team used MUSE, a powerful spectroscopic instrument on the European Southern Observatory’s Very Large Telescope (VLT) in Chile, to study the galaxy UGC 10738, 320 million light-years away. We can’t get a big-picture view of our own galaxy because we’re inside of it, so galaxies like UGC 10728 provide a good analogue. It was found to have both a thin and thick disk, similar to the Milky Way. Other galaxies had previously been found to have thick disks, but his research looked at the metal ratios of the stars to compare how different stellar populations are distributed compared to in our own galaxy. “They were pretty much the same as those in the Milky Way – ancient stars in the thick disc, younger stars in the thin one,” Scott explains. “We’re looking at some other galaxies to make sure, but that’s pretty strong evidence that the two galaxies evolved in the same way.” This suggests that our own galaxy’s shape evolved naturally, without the need for rare and violent interventions – so Milky-Way-type galaxies are likely quite common. Michael Cowley, an astronomer at the Queensland University of Technology who was not involved in the research, says that this kind of research has only been made possible with instruments such as MUSE. “It’s only now, with recent technological improvements (e.g., the integral field spectrograph), we’ve been able to start comparing the chemical construct of distant galaxies to our own to understand if our galaxy is unique or generic in nature,” he explains. Another independent astronomer, Brent Groves from the International Centre for Radio Astronomy Research (ICRAR), agrees: “Getting time on MUSE…is very competitive, thus to achieve that demonstrates that the astronomical community already thinks this is an interesting question.” Groves explains that different types of stars produce different elements – for example, type II supernovae produce elements like oxygen and magnesium, while type Ia supernovae produce heavier elements like iron – so looking at the chemical signatures allows researchers to determine the types and ages of stars in different regions. “Measuring these elements is hard, and needs very sensitive spectra, only possible with big telescopes like the VLT and on nearby galaxies,” he explains. But while UGC 10728 and the Milky Way do appear similar in the results of this new study, there are a few apparent differences, including the fact that UGC10738 appears to be more metal-rich. “What the authors don’t discuss is whether these differences mean something, or are just because UGC10738 is not the Milky Way – meaning, for example, it doesn’t have neighbours like the Magellanic Clouds,” Groves says. “Maybe we need [to study] more galaxies like the Milky Way or a better understanding of the differences between UGC10738 and the Milky Way to understand this.” Cowley agrees that this has the potential to be a powerful result – but “the sample size needs to be increased before a conclusive result can be confirmed – i.e., they need to look at more galaxies”. Research like this can improve the accuracy of our understanding of galaxy formation, which Cowley says has implications across many questions in astronomy, including his own work into supermassive black holes. https://cosmosmagazine.com/space/astronomy/our-galaxy-probably-isnt-that-special/ Quote
Subscriber CaaC (John)+ Posted May 29, 2021 Author Subscriber Posted May 29, 2021 Quote Astronomers create the largest-ever map of our Universe’s dark matter The map covers almost one-eighth of the entire sky. Researchers have created the largest ever map of dark matter, invisible material thought to account for 85 per cent of the total matter of the Universe. As matter curves space-time, astronomers are able to map its existence by looking at light travelling to Earth from distant galaxies. If the light has been distorted, this means there is matter in the foreground, bending the light as it comes towards us. But researchers also found hints, as with previous surveys, the Universe may be a few per cent smoother than predicted. A team co-led by UCL researchers, as part of the international Dark Energy Survey (DES), used artificial intelligence to analyse images of 100 million galaxies, looking at their shape, spots of light made up of 10 or so pixels, to see if they have been stretched. The new map, a representation of all matter detected in the foreground of the observed galaxies, covers a quarter of the southern hemisphere’s sky. Read more about dark matter: Astronomers develop a new way to spot galaxies’ dark matter Wild ideas in science: Dark matter might be under our feet “Most of the matter in the Universe is dark matter,” said co-lead author Dr Niall Jeffrey, UCL physics and astronomy. “It is a real wonder to get a glimpse of these vast, hidden structures across a large portion of the night sky. “These structures are revealed using the distorted shapes of hundreds of millions of distant galaxies with photographs from the Dark Energy Camera in Chile. In our map, which mainly shows dark matter, we see a similar pattern as we do with visible matter only, a web-like structure with dense clumps of matter separated by large empty voids. “Observing these cosmic-scale structures can help us to answer fundamental questions about the Universe.” For decades astronomers have suspected there is more material in the Universe than we can see. Dark matter, like dark energy, remains mysterious, but its existence is inferred from galaxies behaving in unpredicted ways. For instance, the fact that galaxies stay clustered together, and that galaxies within clusters move faster than expected, cannot be explained by our theory of gravity without dark matter. “Visible galaxies form in the densest regions of dark matter,” said co-author Professor Ofer Lahav, UCL Physics and Astronomy, chairman of the DES UK consortium. “When we look at the night sky, we see the galaxy’s light but not the surrounding dark matter, like looking at the lights of a city at night. “By calculating how gravity distorts light, a technique known as gravitational lensing, we get the whole picture, both visible and invisible matter. This brings us closer to understanding what the Universe is made of and how it has evolved. “It also shows the power of artificial intelligence methods to analyse one of the largest data sets in astronomy.” A new analysis of the first three years of the survey by DES scientists suggests matter is distributed throughout the Universe in a way that is consistent with predictions in the standard cosmological model, the best current model of the Universe. The map is described in a new paper published in the Monthly Notices Of The Royal Astronomical Society. In the UK the study received funding from the Science and Technology Facilities Council (STFC) and the Higher Education Funding Council for England. https://www.sciencefocus.com/news/astronomers-create-the-largest-ever-map-of-our-universes-dark-matter/ 1 Quote
Subscriber CaaC (John)+ Posted June 1, 2021 Author Subscriber Posted June 1, 2021 What a load of poo Quote Whether you use a hole in the ground or a fancy gold-plated toilet, on Earth, gravity pulls your waste down and away from you. For astronauts, “doing their duty” is a bit more complicated. Without gravity, any loose drops or dribbles could float out of the toilet. That’s not good for astronauts’ health, nor for the sensitive equipment inside the space station. I study volcanoes on other planets, and I’m interested in how people can work in extreme environments like space. The new toilet is more comfortable, easier to use for both men and women, and lighter. NASA/James Blair via Wikimedia Commons FULL REPORT Quote
nudge Posted June 2, 2021 Posted June 2, 2021 NASA has chosen 4 Discovery-class mission proposals, and will choose the final two today after evaluating the concept studies in the last 9 months. Some very interesting proposals there... https://www.nasa.gov/press-release/nasa-selects-four-possible-missions-to-study-the-secrets-of-the-solar-system/ DAVINCI+ The mission seeks to analyze Venus’ atmosphere to understand how it formed and evolved before determining whether Venus ever had an ocean. The spacecraft will plunge through Venus’ inhospitable atmosphere to precisely measure its composition down to the surface. The instruments are encapsulated within a purpose-built descent sphere to protect them from the intense environment of Venus. The “+” in DAVINCI+ refers to the imaging component of the mission, which includes cameras on the descent sphere and orbiter designed to map surface rock-type. James Garvin of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is the principal investigator. Goddard would provide project management. Io Volcano Observer (IVO) IVO would explore Jupiter’s moon, Io, to learn how tidal forces shape planetary bodies. Io is heated by the constant crush of Jupiter’s gravity and is the most volcanically active body in the solar system. Little is known about Io’s specific characteristics, such as whether a magma ocean exists in its interior. Using close-in flybys, IVO would assess how magma is generated and erupted on Io. The mission’s results could revolutionize our understanding of the formation and evolution of rocky, terrestrial bodies, as well as icy ocean worlds in our solar system, and extrasolar planets across the universe. Alfred McEwen of the University of Arizona in Tucson is the principal investigator. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland would provide project management. TRIDENT Trident would explore Triton, a unique and highly active icy moon of Neptune, to understand pathways to habitable worlds at tremendous distances from the Sun. NASA’s Voyager 2 mission showed that Triton has active resurfacing—generating the second youngest surface in the solar system—with the potential for erupting plumes and an atmosphere. Coupled with an ionosphere that can create organic snow and the potential for an interior ocean, Triton is an exciting exploration target to understand how habitable worlds may develop in our solar system and others. Using a single fly-by, Trident would map Triton, characterize active processes, and determine whether the predicted subsurface ocean exists. Louise Prockter of the Lunar and Planetary Institute/Universities Space Research Association in Houston is the principal investigator. NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, would provide project management VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) VERITAS would map Venus’ surface to determine the planet’s geologic history and understand why Venus developed so differently than the Earth. Orbiting Venus with a synthetic aperture radar, VERITAS charts surface elevations over nearly the entire planet to create three-dimensional reconstructions of topography and confirm whether processes, such as plate tectonics and volcanism, are still active on Venus. VERITAS would also map infrared emissions from the surface to map Venus’ geology, which is largely unknown. Suzanne Smrekar of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, is the principal investigator. JPL would provide project management. Hopefuly, DAVINCI+ will be one of those given the green light, would love to see a lander on Venus! 1 Quote
Subscriber CaaC (John)+ Posted June 3, 2021 Author Subscriber Posted June 3, 2021 Quote ISS struck by space junk International Space Station’s robotic arm punctured by mystery object. Credit: NASA/Canadian Space Agency Space can be an unforgiving environment, even for a spacecraft. The Canadian Space Agency (CSA) has just reported that a small hole has appeared in a robotic arm it operates aboard the International Space Station (ISS) – driving home the risks of space junk. The 5-mm-diameter hole was noticed during a routine inspection of the exterior of the spacecraft on 12 May 2021, but it’s unknown what the object was or when it hit. In a statement, CSA notes that despite the impact to the robotic arm Canadarm2, its performance remains unaffected, and “the damage is limited to a small section of the arms boom and thermal blanket”. The impact was called a “lucky strike”, as it didn’t impact operations or any of the seven astronauts aboard the ISS. But the danger of space junk is ever-present – and only increasing as new satellites are launched into orbit. Earth is surrounded by an ever-growing population of man-made junk, leftover from old spacecraft, obsolete satellites and debris from collisions, for example, the 2009 collision between a defunct Russian spacecraft and a US commercial satellite. As of 2020, the US Space Surveillance Network was tracking over 14,000 bits of debris larger than 10cm across, but there are estimated to be many millions of pieces smaller than that. This might not seem like a huge problem, but when travelling at the blistering speeds of Earth orbit (up to eight kilometres per second!) even a tiny speck of debris could damage spacecraft or operational satellites. Plus, since most pieces of space junk are too small to be monitored, the threat of collision is taken very seriously by space agencies – in fact, several windows of NASA’s space shuttle fleet previously sustained damage from orbiting paint flecks. Luckily, scientists are on the case around the world – the Australian National University, for example, recently announced they’re partnering with industry to develop lasers to push space debris out of orbit, while the Southern Cross Outreach Observatory Project wants to deploy a network of mobile observatories across Australia to create a detailed database of orbiting junk. https://cosmosmagazine.com/space/exploration/iss-struck-by-space-junk/ Quote
Subscriber CaaC (John)+ Posted June 4, 2021 Author Subscriber Posted June 4, 2021 Quote Rocket Team to Discern if Our Star Count Should Go Way Up The universe contains a mind-boggling number of stars – but scientists’ best estimates may be an undercount. A NASA-funded sounding rocket is launching with an improved instrument to look for evidence of extra stars that may have been missed in stellar headcounts. The Cosmic Infrared Background Experiment-2, or CIBER-2, mission is the latest in a series of sounding rocket launches that began in 2009. Led by Michael Zemcov, assistant professor of physics and astronomy at the Rochester Institute of Technology in New York, CIBER-2’s launch window opens at the White Sands Missile Range in New Mexico on June 6, 2021. If you’ve had the pleasure of seeing an open sky on a clear, dark night, you’ve probably been struck by the sheer number of stars. Perhaps you’ve even tried to count them up. (If not, a hint: There are somewhere around five thousand visible to the naked eye from Earth.) But the real wonder is that our speckled night sky represents only the tiniest sample of what’s truly out there. To get a rough estimate of the total number of stars in the universe, scientists have calculated the average number of stars in a galaxy – some estimates put it at about 100 million, though it could be 10 or more times higher – and multiplied it by the number of galaxies, taken to be about 2 trillion (also very tentative). That gets you one hundred quintillion stars (or 1 with 21 zeroes after it). That’s more than 10 stars for every grain of sand on Earth (estimated at about seven and a half quintillion). But even that astronomically high number may be an underestimate. That calculation assumes all, or at least most, stars are inside galaxies. Based on recent findings, that may not be quite true – and it’s what the CIBER-2 mission is trying to figure out. The CIBER-2 instrument, like the earlier CIBER instrument it’s based on, will launch aboard a sounding rocket – a small suborbital rocket that carries scientific instruments on brief trips into space before falling back to Earth for recovery. Once above Earth’s atmosphere, CIBER-2 will survey a patch of sky about 4 square degrees – for reference, the full Moon takes up about half a degree – that includes dozens of galaxy clusters. It won’t count stars, but it will detect the diffuse, cosmos-filling glow known as the extragalactic background light. “This background glow is the total light produced over cosmic history,” said Jamie Bock, professor of physics at Caltech in Pasadena, California, and lead researcher for CIBER’s first four flights. That background light spans a range of wavelengths, but CIBER-2 will focus on a small portion called the cosmic infrared background, or CIB. Much of the CIB is thought to come from M and K dwarfs, the most common star types in the universe, though that’s not the only contributor. “Our method measures the total light, including from sources we haven’t identified yet,” Bock said. When you can’t count up individual stars in a galaxy, the CIB’s brightness should give you a good estimate of how many M and K dwarfs there are. And if all those stars are inside the galaxy, that light should be brightest toward its center. In 2007, scientists used NASA’s Spitzer Space Telescope to look at galaxy clusters and make this type of measurement. But Spitzer observed more light than was expected from known galaxy populations – the fluctuations in brightness of the CIB hinted that they were missing something. Bock and Zemcov – at the time a post-doctoral researcher but now the principal investigator for CIBER-2 – flew the first CIBER mission to check those results with a telescope better optimized for the task. “So we did that measurement, and we came up with an answer that was uncomfortable,” said Zemcov. “There were a lot more fluctuations than we were expecting – one explanation is there is more light coming from outside of galaxies than we had thought.” The extra light, they believe, may be from the glimmer of stray dwarf stars. These stars could have been flung out of their home galaxy when it merged with another, a process known as tidal stripping. Such far-flung stars are known to surround the Milky Way, though current counts suggest there’s not nearly enough of them to produce the signal CIBER measured. “More and more research suggests that there are a significant number of stars of this type outside of galaxies,” Zemcov said. But alternative hypotheses for this excess light have arisen. “We know some of that light comes from galaxies, and some the first stars ever to shine, even though they’re long gone now,” said Bock. Some light from our own galaxy could even pollute the measurements, though the CIBER team has done their best to filter it out. There are also more exotic possibilities, like direct-collapse black holes from the early universe – massive clouds of gas that collapsed into black holes without becoming stars first – whose ultraviolet light would have stretched across expanding space into the longer infrared wavelengths we see today. CIBER-2 was designed to help settle the matter by distinguishing these possibilities. Light from extragalactic M and K dwarfs should spill over into visible range, so CIBER-2 was designed to observe an expanded range of wavelengths – from the near-infrared to green visible light – to see it if it’s there. CIBER-2 can also distinguish light from the first galaxies and stars or early direct-collapsing black holes: Both should have a characteristic portion of their total light missing, the part absorbed by the thick fog of intergalactic hydrogen in the early universe. For now, all the possibilities remain on the table. But if our star count should indeed go up, CIBER-2’s results could soon tell us. “There are hints that we are definitely not catching all the stuff in the universe. And the more people look, the more they see,” said Zemcov. Banner Image: Time-lapse photograph of the Cosmic Infrared Background Experiment (CIBER) rocket launch, taken from NASA's Wallops Flight Facility in Virginia in 2013. The image is from the last of four launches. Credit: University of Tokyo/ T. Arai By Miles Hatfield NASA’s Goddard Space Flight Center, Greenbelt, Md. Quote
Subscriber CaaC (John)+ Posted June 5, 2021 Author Subscriber Posted June 5, 2021 Quote A telescope with sharper eyes than Hubble? Australian-led adaptive optics project signs agreement with the European Southern Observatory. An Australian-led astronomy project has just received the green light to create the most powerful ground-based telescope in the world, giving us a wider, sharper and more sensitive view of the Universe. But this telescope isn’t being built from scratch – instead, it will be an upgrade to the Very Large Telescope (VLT) in Chile, which is composed up of four massive eight-metre telescopes. One of these telescopes will be fitted with the new MAVIS instrument – a $57 million adaptive optics system that will see further and clearer than even the Hubble Space Telescope. “MAVIS will be a powerful instrument that will serve a very large number of key science projects,” explains François Rigaut from the Australian National University, who is leading the MAVIS consortium. “This will include observations of our own Solar System as well as planets around other stars, and the physics of star formation, from the Milky Way to the first star clusters in the Universe.” The MAVIS project has been in the works for a few years now (in fact, we reported on the initial announcement back in 2018), but today an agreement was officially signed between the MAVIS consortium and the European Southern Observatory (ESO), the international astronomy organisation that operates the VLT. Back in 2017, Australia entered into a 10-year partnership with ESO, giving astronomers and industry access to the world-class facilities at the La Silla Paranal Observatory in Chile, where the VLT is located. According to Richard McDermid, MAVIS project scientist from Macquarie University, the project is a significant milestone for this burgeoning relationship – and for our nation’s astronomy research. “MAVIS demonstrates that Australia can not only participate in the scientific life of the observatory but can also be a core player in helping ESO maintain its leadership by developing unique and competitive instruments using Australian expertise,” he says. MAVIS will be a cutting-edge addition to the VLT, helping it capture images that are three times sharper than Hubble. But how’s that possible when Hubble is in orbit, free from the Earth’s troublesomely turbulent atmosphere? It’s because MAVIS (which stands for the Multi-conjugate-adaptive-optics Assisted Visible Imager and Spectrograph) is an adaptive optics instrument that will correct for atmospheric blurring. It will combine with the VLT’s existing adaptive optics technology, including powerful laser guide stars and a deformable mirror that can change its shape hundreds of times a second to correct distortions. MAVIS will add two more adaptive mirrors to this suite. Rigaut explains that “the ability to deliver corrected optical images, over a wide field of view using one of the world’s largest telescope, is what makes MAVIS the first-of-its-kind instrument and means we will be able to observe very faint distant objects”. The MAVIS consortium is led by The Australian National University, with involvement from Macquarie University, Italy’s National Institute for Astrophysics and France’s Laboratoire d’Astrophysique. In return for building the instrument, the consortium will receive guaranteed observing time and financial help from ESO. https://cosmosmagazine.com/space/astronomy/a-telescope-with-sharper-eyes-than-hubble/ 1 Quote
Subscriber CaaC (John)+ Posted June 6, 2021 Author Subscriber Posted June 6, 2021 Quote Microscopic Superheroes to Help Protect Astronaut Health in Space It’s a classic superhero tale: Inconspicuous, underestimated, our hero is revealed to have powers beyond imagination! The hottest and coldest environments on Earth, decades without water, the powerful radiation of space – none of it is any match for…the tardigrade! This chubby, microscopic, eight-legged animal may be an unlikely hero, but tardigrades, also known as water bears due to their shape under a microscope, possess superpowers when it comes to surviving really harsh conditions. Understanding how they tolerate extreme environments – including the one astronaut's experience in space, with microgravity and elevated radiation levels – can better guide research into protecting humans from the stresses of long-duration space travel. An experiment starting aboard the International Space Station, called Cell Science-04, will help reveal how tardigrades do it. “We want to see what ‘tricks’ they use to survive when they arrive in space, and, over time, what tricks their offspring are using,” said Thomas Boothby, assistant professor at the University of Wyoming in Laramie and principal investigator of the experiment. “Are they the same or do they change across generations? We just don’t know what to expect.” One option in the tardigrade bag of tricks could be producing tons more antioxidants to combat harmful changes in the body caused by increased radiation exposure in space. “We have seen them do this in response to radiation on Earth,” said Boothby, “and we think the ways tardigrades have evolved to withstand extreme environments on this planet may also be what protects them against the stresses of spaceflight.” The research team will look at what happens with tardigrade genes in space. Knowing which ones are turned on or off in response to short-term and long-term spaceflight will help researchers identify specific ways tardigrades use to survive in this stressful environment. If one solution they have is to turn up the dial on antioxidant production, for example, genes involved in that process should be affected. Checking which genes are also activated or deactivated by other stresses will help pinpoint the genes that respond exclusively to spaceflight. Cell Science-04 will then test which are truly required for tardigrade adaptation and survival in this high-stress environment. Data from the space station experiment will also offer a comparison for Earth-based research. The latter is more common and less costly and uses simulated spaceflight conditions to study tardigrade responses. The current experiment will tell researchers how similar those conditions are to actual spaceflight. The tiny heroes of Cell Science-04 won’t be the first spacefaring tardigrades to join an astronaut crew. They have already been shown to survive even the vacuum of space when exposed outside the space station for an experiment. This time, they’ll be onboard living and reproducing inside special science hardware developed for the station by NASA’s Ames Research Center in California’s Silicon Valley, which also manages the mission. Called the Bioculture System, the hardware lets scientists carry out long-term studies of cultures of cells, tissues, and microscopic animals in space by allowing real-time, remote monitoring, and finer control over the conditions in which they grow. In the long run, revealing what makes tardigrades so tolerant could lead to ways of protecting biological material, such as food and medicine from extreme temperatures, drying out, and radiation exposure, which will be invaluable for long-duration, deep-space exploration missions. That’s superhero-size potential for the teeny tardigrade. Dr Boothby’s research is supported by NASA’s Biological and Physical Sciences Division. Author: Abby Tabor, NASA's Ames Research Center 1 Quote
nudge Posted June 6, 2021 Posted June 6, 2021 4 minutes ago, CaaC (John) said: They are also sending baby squids... Just look how cute the are! 1 Quote
Subscriber CaaC (John)+ Posted June 11, 2021 Author Subscriber Posted June 11, 2021 Quote New telescope quadruples fast radio burst count in just one year 535 new observations will help answer fundamental questions about the Universe. In just one year of peering up at the Universe, a new telescope in Canada has quadrupled the number of fast radio bursts (FRBs) ever spotted. First discovered in 2007, these immensely powerful flashes of radio waves last mere millisecond but are as brilliant as the brightest galaxies. They appear without warning from random points in the Universe, making it very difficult to predict them, trace them, or even pin down the cosmic phenomena that cause them. Astronomers reckon they might be created by neutron stars or black holes – in fact, last year an FRB from our own galaxy was traced back to a magnetar. But our understanding of these fast flashes has been limited because we haven’t spotted very many. Until recently we’d only seen 140 bursts. Now, the CHIME radio telescope in British Columbia, Canada, has announced that it detected 535 new FRBs in its first year of operation – quadrupling the known number. Perhaps most intriguingly, the new observations reveal that FRBs fall into two classes: repeating and non-repeating. While most seem to be one-shot wonders, astronomers found 18 FRB sources that repeated, with each burst lasting longer and emitting more focused radio frequencies from the once-off FRBs. This suggests that the different classes are created by different mechanisms, perhaps by different astronomical objects. It’s an exciting result because repeating bursts make it easier to pinpoint their origin, giving astronomers multiple chances to catch them. https://cosmosmagazine.com/space/astrophysics/hundreds-of-fast-radio-bursts-spotted/ Quote
Subscriber CaaC (John)+ Posted June 13, 2021 Author Subscriber Posted June 13, 2021 Quote SLS: The first view of Nasa's assembled 'mega-rocket The core stage and twin booster stand taller than the Statue of Liberty Nasa has assembled the first of its powerful Space Launch System (SLS) rockets, which will carry humans to the Moon this decade. On Friday, engineers at Florida's Kennedy Space Center finished lowering the 65m (212ft) -tall core stage in-between two smaller booster rockets. It's the first time all three key elements of the rocket have been together in their launch configuration. Nasa plans to launch the SLS on its maiden flight later this year. During this mission, known as Artemis-1, the SLS will carry Orion - America's next-generation crew vehicle - towards the Moon. However, no astronauts will be aboard; engineers want to put both the rocket and the spaceship through their paces before humans are allowed on in 2023. Test success for the world's most powerful rocket Nasa's giant SLS rocket: a guide Artemis: To the Moon and Beyond Nasa chooses SpaceX to build Moon lander FULL REPORT 1 Quote
nudge Posted June 17, 2021 Posted June 17, 2021 China has successfully brought three taikonauts to the new space station! 1 Quote
Subscriber CaaC (John)+ Posted June 17, 2021 Author Subscriber Posted June 17, 2021 Quote Betelgeuse’s brightness dimmed, and we finally understand why The 'Great Dimming of Betelgeuse', which took place between October 2019 and April 2020, was speculated to be the lead-up to a supernova explosion. Astronomers have discovered the cause of the ‘Great Dimming of Betelgeuse’: a cloud of dust partially concealing it from us. As one of the largest stars visible to the naked eye, the red supergiant star Betelgeuse is a familiar sight to professional and amateur astronomers alike. That’s perhaps why it was so surprising when the star’s brightness started to drop in October 2019. By February 2020, the star, which marks the right shoulder in the constellation of Orion, had hit a record low of only 40 per cent of its usual brightness. This dramatic drop sparked speculation that Betelgeuse was about to go supernova – that is, reach the end of its life as a red supergiant, collapse, and then bounce into a fiery explosion so bright we’d even be able to see it in the daytime. It wasn’t immediately clear to astronomers whether or not this was the case, since a supernova hasn’t been observed in our Galaxy since astronomer Johannes Kepler saw one in 1604. But it never happened, and by April 2020, Betelgeuse was back to normal. Now, images of the star, taken with the European Southern Observatory’s Very Large Telescope, along with data from the GRAVITY instrument, have revealed what happened to it. “We have directly witnessed the formation of so-called stardust,” said Dr Miguel Montargès, from the Observatoire de Paris, France, and KU Leuven, Belgium. “For once, we were seeing the appearance of a star changing in real-time on a scale of weeks.” The surface of Betelgeuse is always changing. Giant bubbles of gas grow, shrink and move around within the star, and occasionally it burps one out. Before the Great Dimming began, Betelgeuse released one of these bubbles. Then, a patch of the star’s surface cooled down, and this temperature drop allowed the gas to cool enough to condense into solid dust. This cloud of dust partially concealed Betelgeuse from the Earth, particularly in the southern region. “The dust expelled from cool evolved stars, such as the ejection we’ve just witnessed, could go on to become the building blocks of terrestrial planets and life,” said Emily Cannon, a PhD student at KU Leuven. “Looking up at the stars at night, these tiny, twinkling dots of light seem perpetual. The dimming of Betelgeuse breaks this illusion.” https://www.sciencefocus.com/news/betelgeuses-brightness-dimmed-and-we-finally-understand-why/ 1 Quote
Subscriber CaaC (John)+ Posted June 20, 2021 Author Subscriber Posted June 20, 2021 Quote On Monday, June 19, 1865, enslaved African Americans in Texas learned of their freedom. That day of liberation became known as Juneteenth, when the Emancipation Proclamation was announced by Union troops in Galveston, Texas. On Thursday, June 17, 2021, President Joe Biden signed into law legislation making Juneteenth, "a federal holiday, recognizing that (1) history should be regarded as a means for understanding the past and solving the challenges of the future; and (2) the celebration of the end of slavery is an important and enriching part of the history and heritage of the United States," said NASA Administrator Bill Nelson. This nighttime image, taken by the Expedition 36 crew aboard the International Space Station in 2013, shows most of the metropolitan areas of Texas, with Galveston in the lower right corner. Image Credit: NASA Last Updated: Jun 18, 2021 Editor: Yvette Smith Quote
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