• 5m

    【狂人日記】Coinbase 上市,是福是禍?今晚揭曉!4 月 14 日行情分析

    Blockcast「區塊客」
  • 5m

    ⇑ Canadian Bitcoin ETF soars past $1B under management

    Hodl Hodl News
  • 12m

    受惠比特幣飆升!概念股 MicroStrategy 連漲兩天

    Blockcast「區塊客」
  • 13m

    Dubai's economic department to roll out blockchain-based corporate KYC

    Cointelegraph
  • 27m

    Cryptocurrency Exchange Binance Announces Listing of Coinbase Stock Token

    Finance Magnates
  • 28m

    Don-Key to take eToro’s approach to yield farming after closing $2.2M round

    AMBCrypto
  • 29m

    Native Bitcoin trading is coming to ShapeShift via THORChain (RUNE)

    CryptoSlate
  • 29m

    Cardano's ADA Soars by 18% and Hits New All-Time High - What's Next?

    Blockchain News
  • 29m

    Binance List the Coinbase Stock Token (COIN)

    TheCryptoBasic
  • 30m

    Exodus привлекла $60 млн через регулируемую SEC продажу токенов-акций

    bits.media
  • 35m

    After Coinbase: What Crypto Companies Will Go Public Next?

    Decrypt
  • 38m

    Bitcoin, Ethereum, and DOGE Reach new ATHs on Same Day

    Coinquora
  • 43m

    On the Modularization of Decentralized Governance

    The Block
  • 43m

    Bitcoin at $64,000 is Amazing But It’s Just the Start, says Market Analyst

    Blockchain News
  • 46m

    The Coinbase direct listing: What you should expect, according to Nasdaq’s IPO impresario

    The Block
  • 47m

    Coinbase Listing on Nasdaq Could Prove Make or Break Event For Crypto

    CoinGape
  • 51m

    Coinbase Stock Token (COIN) Will List In Binance

    Coinquora
  • 53m

    Binance Will List Coinbase Stock Token (COIN) to Trade Against BUSD

    Decrypt
  • 56m

    SEC's 'Crypto Mom' Updates Token Safe Harbor Proposal on GitHub

    CryptoNews
  • 56m

    ZKSwap Technical Analysis 2021 — How Much Will ZKS Be Worth in 2021?

    Coinquora
  • 56m

    6 Blockchain Business Use Cases You Should Know

    TheCryptoBasic
  • 57m

    Эстер Пирс обновила предложение о «регуляторных каникулах» для криптовалютных стартапов

    bits.media
  • 58m

    Bitcoin at $64,000 is Amazing But It’s Just the Start, says Market Analyst

    Blockchain News
  • 58m

    US Filmmaker Kevin Smith Plans to Sell New Horror Movie "Killroy Was Here" As NFT

    Blockchain News
  • 1h

    Chainlink price prediction: LINK to fall back to $35

    Cryptopolitan
  • 1h

    🏆 CLAIM IS LIVE! 🏆 If you participated in the Easter Battle, go claim your prizes and post them on Twitter with #TeamPancakeSwap so we can see! 🥇🥈🥉[pancakeswap.finance] [twitter.com] [pbs.twimg.com]

    Pancake Swap
  • 1h

    Ether price flirts with $2,400 ATH as irreversible hard fork looms

    Cointelegraph
  • 1h

    Coinbase Review: Still The Best In 2021 For Bitcoin Beginners?

    Decrypt
  • 1h

    DOGE soars 80% on the day to become 10th largest crypto by market cap

    Cointelegraph
  • 1h
  • 1h

    Binance and FTX list Coinbase stock tokens ahead of exchange's Nasdaq debut

    Cointelegraph
  • 1h

    What Changed in Crypto Markets While You Were Sleeping — April 14

    be[in]crypto
  • 1h

    Bitcoin on Track To Become Less Volatile Than Fiat Money, Says On-Chain Analyst Willy Woo – Here’s When

    The Daily Hodl
  • 1h

    Coinbase IPO May Push BTC Price to $70,000, Just like Tesla Pushed BTC to $60,000

    Blockchain News
  • 1h

    Ethernity chain launches authenticated NFT marketplace to curtail fraud

    AMBCrypto
  • 1h

    Earn crypto while playing BitKong 

    AMBCrypto
  • 1h

    IRS США планирует увеличить доходы бюджета благодаря налогам с криптовалют

    bits.media
  • 1h

    Binance to Add Tradable Coinbase Stock Token After the Nasdaq Listing

    CryptoPotato
  • 1h

    Coinbase Employees Get Extra Millions That Might Be Spent on BTC and Alts

    CryptoNews
  • 1h

    OptionRoom Token Is Now Listed on AscendEX

    be[in]crypto
  • 1h

    Kraken CEO Fears Overregulation May Force Exchange Out of US

    be[in]crypto
  • 1h

    Dan Morehead: bitcoin price at $115,000 in August

    Cryptonomist
  • 1h

    寄信、寄包裹也能上鏈?美國郵政署擬支援「NFT 郵資」

    Blockcast「區塊客」
  • 1h

    Europe’s CoinShares announces the launch of XRP ETP

    AMBCrypto
  • 2h

    Кевин Маккарти: «регуляторы не должны игнорировать рост биткоина»

    bits.media
  • 08 April
  • 5d

    ST/ Hubble spots double quasars in merging galaxies

    Paradigm Fund
Thu, Apr 8, 2021 4:25 PM by Paradigm Fund

ST/ Hubble spots double quasars in merging galaxies

preview img

Space biweekly vol.23, 26th March — 8th AprilTL;DRNASA’s Hubble Space Telescope is ‘seeing double.’ Peering back 10 billion years into the universe’s past, Hubble astronomers found a pair of quasars that are so close to each other they look like a single object in ground-based telescopic photos, but not in Hubble’s crisp view.We are made of stardust, the saying goes, and a pair of studies including University of Michigan research finds that may be more true than we previously thought.Astronomers have detected X-rays from Uranus for the first time, using NASA’s Chandra X-ray Observatory. This result may help scientists learn more about this enigmatic ice giant planet in our solar system.Researchers from Brown University have discovered a previously unknown type of ancient crater lake on Mars that could reveal clues about the planet’s early climate.Space weather often manifests as substorms, where a beautiful auroral display such as the Northern Lights is accompanied by an electrical current in space which has effects at earth that can interfere with and damage power distribution and electrical systems. Now, the lifecycle of these auroral substorms has been revealed using social media-inspired mathematical tools to analyze space weather observations across the Earth’s surface.A research team of international space scientists, led by Dr Matthias van Ginneken from the University of Kent’s School of Physical Sciences, has found new evidence of a low-altitude meteoritic touchdown event reaching the Antarctic ice sheet 430,000 years ago.New observations with the European Southern Observatory’s Very Large Telescope (ESO’s VLT) indicate that the rogue comet 2I/Borisov, which is only the second and most recently detected interstellar visitor to our Solar System, is one of the most pristine ever observed. Astronomers suspect that the comet most likely never passed close to a star, making it an undisturbed relic of the cloud of gas and dust it formed from.The SwRI-led Ultraviolet Spectrograph (UVS) orbiting Jupiter aboard NASA’s Juno spacecraft has detected new faint aurora features, characterized by ring-like emissions, which expand rapidly over time. SwRI scientists determined that charged particles coming from the edge of Jupiter’s massive magnetosphere triggered these auroral emissions.New research could inform where to one day search for signs of life on Saturn’s moon Enceladus.Scientists reported new research results suggesting that artificial objects in orbit around the Earth are brightening night skies on our planet significantly more than previously understood.New reports highlight Russian, Chinese advances in space weapons.Amazon Web Services launches space accelerator program for startups.Pandemic to cost NASA up to $3 billion.Upcoming industry events. And more!Space industry in numbersThe global smart space market size is projected to grow from USD 9.4 billion in 2020 to USD 15.3 billion by 2025, at a Compound Annual Growth Rate (CAGR) of 10.2% during the forecast period. The increasing venture capital funding and growing investments in smart space technology to drive market growth.Analysts at Morgan Stanley and Goldman Sachs have predicted that economic activity in space will become a multi-trillion-dollar market in the coming decades. Morgan Stanley’s Space Team estimates that the roughly USD 350 billion global space industry could surge to over USD 1 trillion by 2040.Source: Satellite Industry Association, Morgan Stanley Research, Thomson Reuters. *2040 estimatesSpace industry newsCAES and Swissto12 partnership brings 3D printed RF solutions to the USEngine explosion blamed for latest Starship crashGuangzhou moves to establish Chinese commercial space clusterGermany’s space agency selects Lockheed Martin’s traffic management softwareWith Air Force funding, Numerica deploys telescopes to monitor space in broad daylightLockheed Martin makes block buy of launches from ABL Space SystemsCrew Dragon moves to new docking port at ISSRussia continues discussions with China on lunar exploration cooperationTechnology race against China a key concern for Pentagon acquisition nomineeSatellite manufacturer LeoStella eyeing opportunities in U.S. defense marketOSIRIS-REx to make final close approach to asteroid before heading back to EarthStartups selected for geospatial intelligence accelerator programSPAC shareholders approve plan to merge with AST & Science Japanese military strengthens ties with U.S. Space CommandFormer NASA administrator Jim Bridenstine joins Viasat’s boardFCC proposes to allocate spectrum for commercial launchesPandemic to cost NASA up to $3 billionIntelsat’s 2020 revenue drop highlights C-band clearing importanceSpace industry relieved to see National Space Council retainedChina launches second Gaofen-12 Earth observation satelliteInspiration4 announces crew for private SpaceX Crew Dragon missionAmazon Web Services launches space accelerator program for startupsAustralian Defence Force expands Inmarsat satellite partnershipHanwha Systems to launch 2,000 LEO communications satellites by 2030Satellite operators weigh strategies to compete against growing Starlink networkMicrosoft and Thales work to automate satellite image processingSpace explorationHubble Spots Double Quasars in Merging GalaxiesNASA/Goddard Space Flight CenterNASA’s Hubble Space Telescope is “seeing double.” Peering back 10 billion years into the universe’s past, Hubble astronomers found a pair of quasars that are so close to each other they look like a single object in ground-based telescopic photos, but not in Hubble’s crisp view.The researchers believe the quasars are very close to each other because they reside in the cores of two merging galaxies. The team went on to win the “daily double” by finding yet another quasar pair in another colliding galaxy duo.A quasar is a brilliant beacon of intense light from the center of a distant galaxy that can outshine the entire galaxy. It is powered by a supermassive black hole voraciously feeding on inflating matter, unleashing a torrent of radiation.“We estimate that in the distant universe, for every 1,000 quasars, there is one double quasar. So finding these double quasars is like finding a needle in a haystack,” said lead researcher Yue Shen of the University of Illinois at Urbana-Champaign.The discovery of these four quasars offers a new way to probe collisions among galaxies and the merging of supermassive black holes in the early universe, researchers say.Quasars are scattered all across the sky and were most abundant 10 billion years ago. There were a lot of galaxy mergers back then feeding the black holes. Therefore, astronomers theorize there should have been many dual quasars during that time.“This truly is the first sample of dual quasars at the peak epoch of galaxy formation with which we can use to probe ideas about how supermassive black holes come together to eventually form a binary,” said research team member Nadia Zakamska of Johns Hopkins University in Baltimore, Maryland.<a href="https://medium.com/media/dce1e31a3cb0b40ca364cb236880e14e/href">https://medium.com/media/dce1e31a3cb0b40ca364cb236880e14e/href</a>Shen and Zakamska are members of a team that is using Hubble, the European Space Agency’s Gaia space observatory, and the Sloan Digital Sky Survey, as well as several ground-based telescopes, to compile a robust census of quasar pairs in the early universe.The observations are important because a quasar’s role in galactic encounters plays a critical part in galaxy formation, the researchers say. As two close galaxies begin to distort each other gravitationally, their interaction funnels material into their respective black holes, igniting their quasars.Over time, radiation from these high-intensity “light bulbs” launch powerful galactic winds, which sweep out most of the gas from the merging galaxies. Deprived of gas, star formation ceases, and the galaxies evolve into elliptical galaxies.“Quasars make a profound impact on galaxy formation in the universe,” Zakamska said. “Finding dual quasars at this early epoch is important because we can now test our long-standing ideas of how black holes and their host galaxies evolve together.”Astronomers have discovered more than 100 double quasars in merging galaxies so far. However, none of them is as old as the two double quasars in this study.The Hubble images show that quasars within each pair are only about 10,000 light-years apart. By comparison, our Sun is 26,000 light-years from the supermassive black hole in the center of our galaxy.The pairs of host galaxies will eventually merge, and then the quasars also will coalesce, resulting in an even more massive, single solitary black hole.Finding them wasn’t easy. Hubble is the only telescope with vision sharp enough to peer back to the early universe and distinguish two close quasars that are so far away from Earth. However, Hubble’s sharp resolution alone isn’t good enough to find these dual light beacons.Astronomers first needed to figure out where to point Hubble to study them. The challenge is that the sky is blanketed with a tapestry of ancient quasars that flared to life 10 billion years ago, only a tiny fraction of which are dual. It took an imaginative and innovative technique that required the help of the European Space Agency’s Gaia satellite and the ground-based Sloan Digital Sky Survey to compile a group of potential candidates for Hubble to observe.Located at Apache Point Observatory in New Mexico, the Sloan telescope produces three-dimensional maps of objects throughout the sky. The team pored through the Sloan survey to identify the quasars to study more closely.The researchers then enlisted the Gaia observatory to help pinpoint potential double-quasar candidates. Gaia measures the positions, distances, and motions of nearby celestial objects very precisely. But the team devised a new, innovative application for Gaia that could be used for exploring the distant universe. They used the observatory’s database to search for quasars that mimic the apparent motion of nearby stars. The quasars appear as single objects in the Gaia data. However, Gaia can pick up a subtle, unexpected “jiggle” in the apparent position of some of the quasars it observes.The quasars aren’t moving through space in any measurable way, but instead their jiggle could be evidence of random fluctuations of light as each member of the quasar pair varies in brightness. Quasars flicker in brightness on timescales of days to months, depending on their black hole’s feeding schedule.This alternating brightness between the quasar pair is similar to seeing a railroad crossing signal from a distance. As the lights on both sides of the stationary signal alternately flash, the sign gives the illusion of “jiggling.”When the first four targets were observed with Hubble, its crisp vision revealed that two of the targets are two close pairs of quasars. The researchers said it was a “light bulb moment” that verified their plan of using Sloan, Gaia, and Hubble to hunt for the ancient, elusive double powerhouses.Team member Xin Liu of the University of Illinois at Urbana-Champaign called the Hubble confirmation a “happy surprise.” She has long hunted for double quasars closer to Earth using different techniques with ground-based telescopes. “The new technique can not only discover dual quasars much further away, but it is much more efficient than the methods we’ve used before,” she said.Their Nature Astronomy article is a “proof of concept that really demonstrates that our targeted search for dual quasars is very efficient,” said team member Hsiang-Chih Hwang, a graduate student at Johns Hopkins University and the principal investigator of the Hubble program. “It opens a new direction where we can accumulate a lot more interesting systems to follow up, which astronomers weren’t able to do with previous techniques or datasets.”The team also obtained follow-up observations with the National Science Foundation NOIRLab’s Gemini telescopes. “Gemini’s spatially-resolved spectroscopy can unambiguously reject interlopers due to chance superpositions from unassociated star-quasar systems, where the foreground star is coincidentally aligned with the background quasar,” said team member Yu-Ching Chen, a graduate student at the University of Illinois at Urbana-Champaign.Although the team is convinced of their result, they say there is a slight chance that the Hubble snapshots captured double images of the same quasar, an illusion caused by gravitational lensing. This phenomenon occurs when the gravity of a massive foreground galaxy splits and amplifies the light from the background quasar into two mirror images. However, the researchers think this scenario is highly unlikely because Hubble did not detect any foreground galaxies near the two quasar pairs.Galactic mergers were more plentiful billions of years ago, but a few are still happening today. One example is NGC 6240, a nearby system of merging galaxies that has two and possibly even three supermassive black holes. An even closer galactic merger will occur in a few billion years when our Milky Way galaxy collides with neighboring Andromeda galaxy. The galactic tussle would likely feed the supermassive black holes in the core of each galaxy, igniting them as quasars.Earth’s carbon deficit caused by early loss through irreversible sublimationby J. Li, E. A. Bergin, G. A. Blake, F. J. Ciesla, M. M. Hirschmann in Science Advances&Early volatile depletion on planetesimals inferred from C–S systematics of iron meteorite parent bodiesby Marc M. Hirschmann, Edwin A. Bergin, Geoff A. Blake, Fred J. Ciesla, Jie Li in Proceedings of the National Academy of SciencesWe are made of stardust, the saying goes, and a pair of studies including University of Michigan research finds that may be more true than we previously thought.The first study, led by U-M researcher Jie (Jackie) Li and published in Science Advances, finds that most of the carbon on Earth was likely delivered from the interstellar medium, the material that exists in space between stars in a galaxy. This likely happened well after the protoplanetary disk, the cloud of dust and gas that circled our young sun and contained the building blocks of the planets, formed and warmed up.Carbon was also likely sequestered into solids within one million years of the sun’s birth — which means that carbon, the backbone of life on earth, survived an interstellar journey to our planet.Previously, researchers thought carbon in the Earth came from molecules that were initially present in nebular gas, which then accreted into a rocky planet when the gases were cool enough for the molecules to precipitate. Li and her team, which includes U-M astronomer Edwin Bergin, Geoffrey Blake of the California Institute of Technology, Fred Ciesla of the University of Chicago and Marc Hirschmann of the University of Minnesota, point out in this study that the gas molecules that carry carbon wouldn’t be available to build the Earth because once carbon vaporizes, it does not condense back into a solid.“The condensation model has been widely used for decades. It assumes that during the formation of the sun, all of the planet’s elements got vaporized, and as the disk cooled, some of these gases condensed and supplied chemical ingredients to solid bodies. But that doesn’t work for carbon,” said Li, a professor in the U-M Department of Earth and Environmental Sciences.Much of carbon was delivered to the disk in the form of organic molecules. However, when carbon is vaporized, it produces much more volatile species that require very low temperatures to form solids. More importantly, carbon does not condense back again into an organic form. Because of this, Li and her team inferred most of Earth’s carbon was likely inherited directly from the interstellar medium, avoiding vaporization entirely.To better understand how Earth acquired its carbon, Li estimated the maximum amount of carbon Earth could contain. To do this, she compared how quickly a seismic wave travels through the core to the known sound velocities of the core. This told the researchers that carbon likely makes up less than half a percent of Earth’s mass. Understanding the upper bounds of how much carbon the Earth might contain tells the researchers information about when the carbon might have been delivered here.“We asked a different question: We asked how much carbon could you stuff in the Earth’s core and still be consistent with all the constraints,” Bergin said, professor and chair of the U-M Department of Astronomy. “There’s uncertainty here. Let’s embrace the uncertainty to ask what are the true upper bounds for how much carbon is very deep in the Earth, and that will tell us the true landscape we’re within.”A planet’s carbon must exist in the right proportion to support life as we know it. Too much carbon, and the Earth’s atmosphere would be like Venus, trapping heat from the sun and maintaining a temperature of about 880 degrees Fahrenheit. Too little carbon, and Earth would resemble Mars: an inhospitable place unable to support water-based life, with temperatures around minus 60.The sublimation sequence of carbon in the solar nebula.In a second study by the same group of authors, but led by Hirschmann of the University of Minnesota, the researchers looked at how carbon is processed when the small precursors of planets, known as planetesimals, retain carbon during their early formation. By examining the metallic cores of these bodies, now preserved as iron meteorites, they found that during this key step of planetary origin, much of the carbon must be lost as the planetesimals melt, form cores and lose gas. This upends previous thinking, Hirschmann says.“Most models have the carbon and other life-essential materials such as water and nitrogen going from the nebula into primitive rocky bodies, and these are then delivered to growing planets such as Earth or Mars,” said Hirschmann, professor of earth and environmental sciences. “But this skips a key step, in which the planetesimals lose much of their carbon before they accrete to the planets.”Hirschmann’s study was recently published in Proceedings of the National Academy of Sciences.“The planet needs carbon to regulate its climate and allow life to exist, but it’s a very delicate thing,” Bergin said. “You don’t want to have too little, but you don’t want to have too much.”Bergin says the two studies both describe two different aspects of carbon loss — and suggest that carbon loss appears to be a central aspect in constructing the Earth as a habitable planet.“Answering whether or not Earth-like planets exist elsewhere can only be achieved by working at the intersection of disciplines like astronomy and geochemistry,” said Ciesla, a U. of C. professor of geophysical sciences. “While approaches and the specific questions that researchers work to answer differ across the fields, building a coherent story requires identifying topics of mutual interest and finding ways to bridge the intellectual gaps between them. Doing so is challenging, but the effort is both stimulating and rewarding.”Blake, a co-author on both studies and a Caltech professor of cosmochemistry and planetary science, and of chemistry, says this kind of interdisciplinary work is critical.“Over the history of our galaxy alone, rocky planets like the Earth or a bit larger have been assembled hundreds of millions of times around stars like the Sun,” he said. “Can we extend this work to examine carbon loss in planetary systems more broadly? Such research will take a diverse community of scholars.”C and S compositions of chondrite meteorite groups plotted as log C/S versus log C. (A) Average compositions of different chondrite groups; (B) average compositions of carbonaceous and ordinary chondrites, sorted by petrologic type, plus average compositions of primitive achondrite groups, acapulcoites, and winonaites.A large meteoritic event over Antarctica ca. 430 ka ago inferred from chondritic spherules from the Sør Rondane Mountainsby M. Van Ginneken, S. Goderis, N. Artemieva, V. Debaille, S. Decrée, R. P. Harvey, K. A. Huwig, L. Hecht, S. Yang, F. E. D. Kaufmann, B. Soens, M. Humayun, F. Van Maldeghem, M. J. Genge, P. Claeys in Science AdvancesA research team of international space scientists, led by Dr Matthias van Ginneken from the University of Kent’s School of Physical Sciences, has found new evidence of a low-altitude meteoritic touchdown event reaching the Antarctic ice sheet 430,000 years ago.Extra-terrestrial particles (condensation spherules) recovered on the summit of Walnumfjellet (WN) within the Sør Rondane Mountains, Queen Maud Land, East Antarctica, indicate an unusual touchdown event where a jet of melted and vaporised meteoritic material resulting from the atmospheric entry of an asteroid at least 100 m in size reached the surface at high velocity.This type of explosion caused by a single-asteroid impact is described as intermediate, as it is larger than an airburst, but smaller than an impact cratering event.The chondritic bulk major, trace element chemistry and high nickel content of the debris demonstrate the extra-terrestrial nature of the recovered particles. Their unique oxygen isotopic signatures indicate that their interacted with oxygen derived from the Antarctic ice sheet during their formation in the impact plume.The findings indicate an impact much more hazardous that the Tunguska and Chelyabinsk events over Russia in 1908 and 2013, respectively.This research, guides an important discovery for the geological record where evidence of such events in scarce. This is primarily due to the difficult in identifying and characterising impact particles.The study highlights the importance of reassessing the threat of medium-sized asteroids, as it likely that similar touchdown events will produce similar particles. Such an event would be entirely destructive over a large area, corresponding to the area of interaction between the hot jet and the ground.Dr van Ginneken said: ‘To complete Earth’s asteroid impact record, we recommend that future studies should focus on the identification of similar events on different targets, such as rocky or shallow oceanic basements, as the Antarctic ice sheet only covers 9% of Earth’s land surface. Our research may also prove useful for the identification of these events in deep sea sediment cores and, if plume expansion reaches landmasses, the sedimentary record.‘While touchdown events may not threaten human activity if occurring over Antarctica, if it was to take place above a densely populated area, it would result in millions of casualties and severe damages over distances of up to hundreds of kilometres.’Location of the sampling site in WN, Sør Rondane Mountains, Queen Maud Land, Antarctica.A Low Signal Detection of X‐Rays From Uranusby W. R. Dunn, J.‐U. Ness, L. Lamy, G. R. Tremblay, G. Branduardi‐Raymont, B. Snios, R. P. Kraft, Z. Yao, A. D. Wibisono in Journal of Geophysical Research: Space PhysicsAstronomers have detected X-rays from Uranus for the first time, using NASA’s Chandra X-ray Observatory. This result may help scientists learn more about this enigmatic ice giant planet in our solar system.Uranus is the seventh planet from the Sun and has two sets of rings around its equator. The planet, which has four times the diameter of Earth, rotates on its side, making it different from all other planets in the solar system. Since Voyager 2 was the only spacecraft to ever fly by Uranus, astronomers currently rely on telescopes much closer to Earth, like Chandra and the Hubble Space Telescope, to learn about this distant and cold planet that is made up almost entirely of hydrogen and helium.In the new study, researchers used Chandra observations taken in Uranus in 2002 and then again in 2017. They saw a clear detection of X-rays from the first observation, just analyzed recently, and a possible flare of X-rays in those obtained fifteen years later. The main graphic shows a Chandra X-ray image of Uranus from 2002 (in pink) superimposed on an optical image from the Keck-I Telescope obtained in a separate study in 2004. The latter shows the planet at approximately the same orientation as it was during the 2002 Chandra observations.What could cause Uranus to emit X-rays? The answer: mainly the Sun. Astronomers have observed that both Jupiter and Saturn scatter X-ray light given off by the Sun, similar to how Earth’s atmosphere scatters the Sun’s light. While the authors of the new Uranus study initially expected that most of the X-rays detected would also be from scattering, there are tantalizing hints that at least one other source of X-rays is present. If further observations confirm this, it could have intriguing implications for understanding Uranus.One possibility is that the rings of Uranus are producing X-rays themselves, which is the case for Saturn’s rings. Uranus is surrounded by charged particles such as electrons and protons in its nearby space environment. If these energetic particles collide with the rings, they could cause the rings to glow in X-rays. Another possibility is that at least some of the X-rays come from auroras on Uranus, a phenomenon that has previously been observed on this planet at other wavelengths.On Earth, we can see colorful light shows in the sky called auroras, which happen when high-energy particles interact with the atmosphere. X-rays are emitted in Earth’s auroras, produced by energetic electrons after they travel down the planet’s magnetic field lines to its poles and are slowed down by the atmosphere. Jupiter has auroras, too. The X-rays from auroras on Jupiter come from two sources: electrons traveling down magnetic field lines, as on Earth, and positively charged atoms and molecules raining down at Jupiter’s polar regions. However, scientists are less certain about what causes auroras on Uranus. Chandra’s observations may help figure out this mystery.Uranus is an especially interesting target for X-ray observations because of the unusual orientations of its spin axis and its magnetic field. While the rotation and magnetic field axes of the other planets of the solar system are almost perpendicular to the plane of their orbit, the rotation axis of Uranus is nearly parallel to its path around the Sun. Furthermore, while Uranus is tilted on its side, its magnetic field is tilted by a different amount, and offset from the planet’s center. This may cause its auroras to be unusually complex and variable. Determining the sources of the X-rays from Uranus could help astronomers better understand how more exotic objects in space, such as growing black holes and neutron stars, emit X-rays.<a href="https://medium.com/media/8c8ad937781b819948cef5a71f608381/href">https://medium.com/media/8c8ad937781b819948cef5a71f608381/href</a>A Noachian Proglacial Paleolake on Mars: Fluvial Activity and Lake Formation within a Closed-source Drainage Basin Crater and Implications for Early Mars Climateby Benjamin D. Boatwright, James W. Head in The Planetary Science JournalResearchers from Brown University have discovered a previously unknown type of ancient crater lake on Mars that could reveal clues about the planet’s early climate.In a study a research team led by Brown Ph.D. student Ben Boatwright describes an as-yet unnamed crater with some puzzling characteristics. The crater’s floor has unmistakable geologic evidence of ancient stream beds and ponds, yet there’s no evidence of inlet channels where water could have entered the crater from outside, and no evidence of groundwater activity where it could have bubbled up from below.So where did the water come from?The researchers conclude that the system was likely fed by runoff from a long-lost Martian glacier. Water flowed into the crater atop the glacier, which meant it didn’t leave behind a valley as it would have had it flowed directly on the ground. The water eventually emptied into the low-lying crater floor, where it left its geological mark on the bare Martian soil.The type of lake described in this study differs starkly from other Martian crater lakes, like those at Gale and Jezero craters where NASA rovers are currently exploring.“This is a previously unrecognized type of hydrological system on Mars,” Boatwright said. “In lake systems characterized so far, we see evidence of drainage coming from outside the crater, breaching the crater wall and in some cases flowing out the other side. But that’s not what is happening here. Everything is happening inside the crater, and that’s very different than what’s been characterized before.”Importantly, Boatwright says, the crater provides key clues about the early climate of Mars. There’s little doubt that the Martian climate was once warmer and wetter than the frozen desert the planet is today. What’s less clear, however, is whether Mars had an Earthlike climate with continually flowing water for millennia, or whether it was mostly cold and icy with fleeting periods of warmth and melting. Climate simulations for early Mars suggest temperatures rarely peaking above freezing, but geological evidence for cold and icy conditions has been sparse, Boatwright says. This new evidence of ancient glaciation could change that.“The cold and icy scenario has been largely theoretical — something that arises from climate models,” Boatwright said. “But the evidence for glaciation we see here helps to bridge the gap between theory and observation. I think that’s really the big takeaway here.”Boatwright was able to map out the details of the crater’s lake system using high-resolution images taken by NASA’s Mars Reconnaissance Orbiter. The images revealed a telltale signature of ancient streambeds — features called inverted fluvial channels. When water flows across a rocky surface, it can leave behind course-grained sediment inside the valley it erodes. When these sediments interact with water, they can form minerals that are harder than the surrounding rock. As further erosion over millions of years whittles the surrounding rock away, the mineralized channels are left behind as raised ridges spidering across the landscape. These features, along with sediment deposits and shoreline features, clearly show where water flowed and ponded on the crater floor.To figure it out, Boatwright worked with Jim Head, his advisor and a research professor at Brown. They ruled out groundwater activity, as the crater lacked telltale sapping channels that form in groundwater systems. These channels usually appear as short, stubby channels that lack tributaries — completely opposite from the dense, branching networks of inverted channels observed in the crater. A careful examination of the crater wall also revealed a distinct set of ridges that face upward toward the crater wall. The features are consistent with ridges formed where a glacier terminates and deposits mounds of rocky debris. Taken together, the evidence points to a glacier-fed system, the researchers concluded.Subsequent research has shown that this crater isn’t the only one of its kind. At this month’s Lunar and Planetary Science Conference, Boatwright presented research revealing more than 40 additional craters that appear to have related features.Head says that these new findings could be critical in understanding the climate of early Mars.“We have these models telling us that early Mars would have been cold and icy, and now we have some really compelling geological evidence to go with it,” Head said. “Not only that, but this crater provides the criteria we need to start looking for even more evidence to test this hypothesis, which is really exciting.”Unusual polarimetric properties for interstellar comet 2I/Borisovby S. Bagnulo, A. Cellino, L. Kolokolova, R. Nežič, T. Santana-Ros, G. Borisov, A. A. Christou, Ph. Bendjoya, M. Devogèle in Nature Communications&Compact pebbles and the evolution of volatiles in the interstellar comet 2I/Borisovby Bin Yang, Aigen Li, Martin A. Cordiner, Chin-Shin Chang, Olivier R. Hainaut, Jonathan P. Williams, Karen J. Meech, Jacqueline V. Keane, Eric Villard in Nature AstronomyObservatory’s Very Large Telescope (ESO’s VLT) indicate that the rogue comet 2I/Borisov, which is only the second and most recently detected interstellar visitor to our Solar System, is one of the most pristine ever observed. Astronomers suspect that the comet most likely never passed close to a star, making it an undisturbed relic of the cloud of gas and dust it formed from.2I/Borisov was discovered by amateur astronomer Gennady Borisov in August 2019 and was confirmed to have come from beyond the Solar System a few weeks later. “2I/Borisov could represent the first truly pristine comet ever observed,” says Stefano Bagnulo of the Armagh Observatory and Planetarium, Northern Ireland, UK, who led the new study. The team believes that the comet had never passed close to any star before it flew by the Sun in 2019.Bagnulo and his colleagues used the FORS2 instrument on ESO’s VLT, located in northern Chile, to study 2I/Borisov in detail using a technique called polarimetry. Since this technique is regularly used to study comets and other small bodies of our Solar System, this allowed the team to compare the interstellar visitor with our local comets.The team found that 2I/Borisov has polarimetric properties distinct from those of Solar System comets, with the exception of Hale-Bopp. Comet Hale-Bopp received much public interest in the late 1990s as a result of being easily visible to the naked eye, and also because it was one of the most pristine comets astronomers had ever seen. Prior to its most recent passage, Hale-Bopp is thought to have passed by our Sun only once and had therefore barely been affected by solar wind and radiation. This means it was pristine, having a composition very similar to that of the cloud of gas and dust it — and the rest of the Solar System — formed from some 4.5 billion years ago.By analysing the polarisation together with the colour of the comet to gather clues on its composition, the team concluded that 2I/Borisov is in fact even more pristine than Hale-Bopp. This means it carries untarnished signatures of the cloud of gas and dust it formed from.“The fact that the two comets are remarkably similar suggests that the environment in which 2I/Borisov originated is not so different in composition from the environment in the early Solar System,” says Alberto Cellino, a co-author of the study, from the Astrophysical Observatory of Torino, National Institute for Astrophysics (INAF), Italy.Olivier Hainaut, an astronomer at ESO in Germany who studies comets and other near-Earth objects but was not involved in this new study, agrees. “The main result — that 2I/Borisov is not like any other comet except Hale-Bopp — is very strong,” he says, adding that “it is very plausible they formed in very similar conditions.”Panel a refers to the RF filter, and panel b to the IF filter. Red filled circles: data for 2I/Borisov. Empty blue, magenta and light blue circles: data for C/1995 O1 (Hale-Bopp), comet 1P/Halley and other comets, respectively. All data points are plotted with 1σ error bars, calculated as explained in Methods subsection Polarimetry. The blue solid lines represent the best-fit model to the Hale-Bopp data obtained with Eq.; dotted lines show the ±1σ and ±2σ uncertainties, dashed lines show its ±3σ uncertainties.“The arrival of 2I/Borisov from interstellar space represented the first opportunity to study the composition of a comet from another planetary system and check if the material that comes from this comet is somehow different from our native variety,” explains Ludmilla Kolokolova, of the University of Maryland in the US.Bagnulo hopes astronomers will have another, even better, opportunity to study a rogue comet in detail before the end of the decade. “ESA is planning to launch Comet Interceptor in 2029, which will have the capability of reaching another visiting interstellar object, if one on a suitable trajectory is discovered,” he says, referring to an upcoming mission by the European Space Agency.An origin story hidden in the dustEven without a space mission, astronomers can use Earth’s many telescopes to gain insight into the different properties of rogue comets like 2I/Borisov. “Imagine how lucky we were that a comet from a system light-years away simply took a trip to our doorstep by chance,” says Bin Yang, an astronomer at ESO in Chile, who also took advantage of 2I/Borisov’s passage through our Solar System to study this mysterious comet.They discovered that 2I/Borisov’s coma — an envelope of dust surrounding the main body of the comet — contains compact pebbles, grains about one millimetre in size or larger. In addition, they found that the relative amounts of carbon monoxide and water in the comet changed drastically as it neared the Sun. The team, which also includes Olivier Hainaut, says this indicates that the comet is made up of materials that formed in different places in its planetary system.The observations by Yang and her team suggest that matter in 2I/Borisov’s planetary home was mixed from near its star to further out, perhaps because of the existence of giant planets, whose strong gravity stirs material in the system. Astronomers believe that a similar process occurred early in the life of our Solar System.While 2I/Borisov was the first rogue comet to pass by the Sun, it was not the first interstellar visitor. The first interstellar object to have been observed passing by our Solar System was ?Oumuamua, another object studied with ESO’s VLT back in 2017. Originally classified as a comet, ?Oumuamua was later reclassified as an asteroid as it lacked a coma.Detection and Characterization of Circular Expanding UV‐Emissions Observed in Jupiter’s Polar Auroral Regionsby V. Hue, T. K. Greathouse, G. R. Gladstone, B. Bonfond, J.‐C. Gérard, M. F. Vogt, D. C. Grodent, M. H. Versteeg, J. A. Kammer, G. Clark, R. W. Ebert, R. S. Giles, M. W. Davis, K. Haewsantati, S. J. Bolton, S. M. Levin, J. E. P. Connerney in Journal of Geophysical Research: Space PhysicsThe SwRI-led Ultraviolet Spectrograph (UVS) orbiting Jupiter aboard NASA’s Juno spacecraft has detected new faint aurora features, characterized by ring-like emissions, which expand rapidly over time. SwRI scientists determined that charged particles coming from the edge of Jupiter’s massive magnetosphere triggered these auroral emissions.“We think these newly discovered faint ultraviolet features originate millions of miles away from Jupiter, near the Jovian magnetosphere’s boundary with the solar wind,” said Dr. Vincent Hue, lead author of a paper accepted by the Journal of Geophysical Research: Space Physics. “The solar wind is a supersonic stream of charged particles emitted by the Sun. When they reach Jupiter, they interact with its magnetosphere in a way that is still not well understood.”Both Jupiter and Earth have magnetic fields that provide protection from the solar wind. The stronger the magnetic field, the larger the magnetosphere. Jupiter’s magnetic field is 20,000 times stronger than Earth’s and creates a magnetosphere so large it begins to deflect the solar wind 2–4 million miles before it reaches Jupiter.“Despite decades of observations from Earth combined with numerous in-situ spacecraft measurements, scientists still do not fully understand the role the solar wind plays in moderating Jupiter’s auroral emissions,” said SwRI’s Dr. Thomas Greathouse, a co-author on this study. “Jupiter’s magnetospheric dynamics, the motion of charged particles within its magnetosphere, is largely controlled by Jupiter’s 10-hour rotation, the fastest in the solar system. The solar wind’s role is still debated.”One of the goals of the Juno mission, recently approved by NASA for an extension until 2025, is to explore Jupiter’s magnetosphere by measuring its auroras with the UVS instrument. Previous observations with the Hubble Space Telescope and Juno have allowed scientists to determine that most of Jupiter’s powerful auroras are generated by internal processes, that is the motion of charged particles within the magnetosphere. However, on numerous occasions, UVS has detected a faint type of aurora, characterized by rings of emissions expanding rapidly with time.“The high-latitude location of the rings indicates that the particles causing the emissions are coming from the distant Jovian magnetosphere, near its boundary with the solar wind,” said Bertrand Bonfond, a co-author on this study from Belgium’s Liège University. In this region, plasma from the solar wind often interacts with the Jovian plasma in a way that is thought to form “Kelvin-Helmholtz” instabilities. These phenomena occur when there are shear velocities, such as at the interface between two fluids moving at different speeds. Another potential candidate to produce the rings are dayside magnetic reconnection events, where oppositely directed Jovian and interplanetary magnetic fields converge, rearrange and reconnect.Both of these processes are thought to generate particle beams that could travel along the Jovian magnetic field lines, to eventually precipitate and trigger the ring auroras on Jupiter.“Although this study does not conclude what processes produce these features, the Juno extended mission will allow us to capture and study more of these faint transient events,” Hue said.A pole-to-equator ocean overturning circulation on Enceladusby Lobo, A.H., Thompson, A.F., Vance, S.D. et al. in Nat. GeosciBuried beneath 20 kilometers of ice, the subsurface ocean of Enceladus — one of Saturn’s moons — appears to be churning with currents akin to those on Earth.The theory, derived from the shape of Enceladus’s ice shell, challenges the current thinking that the moon’s global ocean is homogenous, apart from some vertical mixing driven by the warmth of the moon’s core.Enceladus, a tiny frozen ball about 500 kilometers in diameter (about 1/7th the diameter of Earth’s moon), is the sixth largest moon of Saturn. Despite its small size, Enceladus attracted the attention of scientists in 2014 when a flyby of the Cassini spacecraft discovered evidence of its large subsurface ocean and sampled water from geyser-like eruptions that occur through fissures in the ice at the south pole. It is one of the few locations in the solar system with liquid water (another is Jupiter’s moon Europa), making it a target of interest for astrobiologists searching for signs of life.The ocean on Enceladus is almost entirely unlike Earth’s. Earth’s ocean is relatively shallow (an average of 3.6 km deep), covers three-quarters of the planet’s surface, is warmer at the top from the sun’s rays and colder in the depths near the seafloor, and has currents that are affected by wind; Enceladus, meanwhile, appears to have a globe-spanning and completely subsurface ocean that is at least 30 km deep and is cooled at the top near the ice shell and warmed at the bottom by heat from the moon’s core.Despite their differences, Caltech graduate student Ana Lobo (MS ’17) suggests that oceans on Enceladus have currents akin to those on Earth. The work builds on measurements by Cassini as well as the research of Andrew Thompson, professor of environmental science and engineering, who has been studying the way that ice and water interact to drive ocean mixing around Antarctica.The oceans of Enceladus and Earth share one important characteristic: they are salty. And as shown by findings published in Nature Geoscience on March 25, variations in salinity could serve as drivers of the ocean circulation on Enceladus, much as they do in Earth’s Southern Ocean, which surrounds Antarctica.Lobo and Thompson collaborated on the work with Steven Vance and Saikiran Tharimena of JPL, which Caltech manages for NASA.Gravitational measurements and heat calculations from Cassini had already revealed that the ice shell is thinner at the poles than at the equator. Regions of thin ice at the poles are likely associated with melting and regions of thick ice at the equator with freezing, Thompson says. This affects the ocean currents because when salty water freezes, it releases the salts and makes the surrounding water heavier, causing it to sink. The opposite happens in regions of melt.“Knowing the distribution of ice allows us to place constraints on circulation patterns,” Lobo explains. An idealized computer model, based on Thompson’s studies of Antarctica, suggests that the regions of freezing and melting, identified by the ice structure, would be connected by the ocean currents. This would create a pole-to-equator circulation that influences the distribution of heat and nutrients.“Understanding which regions of the subsurface ocean might be the most hospitable to life as we know it could one day inform efforts to search for signs of life,” Thompson says.A pole-to-equator ocean overturning circulation on EnceladusNetwork community structure of substorms using SuperMAG magnetometersby L. Orr, S. C. Chapman, J. W. Gjerloev, W. Guo in Nature CommunicationsSpace weather often manifests as substorms, where a beautiful auroral display such as the Northern Lights is accompanied by an electrical current in space which has effects at earth that can interfere with and damage power distribution and electrical systems. Now, the lifecycle of these auroral substorms has been revealed using social media-inspired mathematical tools to analyse space weather observations across the Earth’s surface.Analysis by researchers led by the University of Warwick has revealed that these substorms manifest as global-scale electrical current systems associated with the spectacular aurora, reaching across over a third of the globe at high latitudes.New research which involves the University of Warwick, John Hopkins University — Applied Physics Laboratory, University of Bergen and Cranfield University, processes data on disturbances in the Earth’s magnetic field from over a hundred magnetometers in the Northern hemisphere using a new technique that enables them to find ‘like-minded friends’.Magnetometers register changes in the Earth’s magnetic field. When charged particles from our Sun bombard the Earth’s magnetic field, it stores up energy like a battery. Eventually, this energy is released leading to large-scale electrical currents in the ionosphere which generate disturbances of magnetic fields on the ground. At extremes, this can disrupt power lines, electronic and communications systems and technologies such as GPS.Using historical data from the SuperMAG collaboration of magnetometers, the researchers applied algorithms from network science to find correlations between magnetometer signals during 41 known substorms that occurred between 1997–2001. These use the same principles that allow a social networking site to recommend new friends, or to push relevant advertisements to you as you browse the internet.Magnetometers detecting coherent signals were linked into communities, regardless of where they were located on the globe. As time progressed, they saw each substorm develop from many smaller communities into a single large correlated system or community at its peak. This led the authors to conclude that substorms are one coherent current system which extends over most of the nightside high latitude globe, rather than a number of individual small and disjointed current systems.Dr Lauren Orr, who led the research as part of her PhD at the University of Warwick Department of Physics and is now based at Lancaster University, said: “We used a well-established method within network science called community detection and applied it to a space weather problem. The idea is that if you have lots of little subgroups within a big group, it can pick out the subgroups. We applied this to space weather to pick out groups within magnetometer stations on the Earth. From that, we were trying to find out whether there was one large current system or lots of separate individual current systems. This is a good way of letting the data tell us what’s going on, instead of trying to fit observations to what we think is occurring.”Some recent work has suggested that auroral substorms are composed of a number of smaller electrical current systems and remain so throughout their lifecycle. This new research demonstrates that while the substorm begins as lots of smaller disturbances, it quite rapidly becomes a large system over the course of around ten minutes. The lack of correlation in its early stages may also suggest that there is no single mechanism at play in how these substorms evolve.The results have implications for models designed to predict space weather. Space weather was included in the UK National Risk Register in 2012 and updated in 2017 with a recommendation for more investment in forecasting.Co-author Professor Sandra Chapman adds: “Our research introduces a whole new methodology for looking at this data. We’ve gone from a data poor to a data rich era in space plasma physics and space weather, so we need new tools. It’s a first to show that you can take one of these tools to our field and get a really important result out of it. We’ve had to learn a lot to be able to do that, but in doing so it opens up a new window into the data.”The abscissa of all panels is normalized time (t′=0 is onset (dashed green line) and t′=30 (dashed purple line) is the time of maximum auroral bulge expansion). Vertical gray dashed lines show ten normalized minute intervals within the expansion phase. a, b Plots individual communities as circles where the size of the circle reflects the number of connections within the community. The ordinate plots the mean magnetic local time/latitude (MLT/MLAT in h/degrees) of the community, ϕx¯(t′), and the color indicates the proportion of connections with each time lag, ∣τc∣. The dashed lines overplotted are the edges of the auroral bulge (MLT) and the onset location (MLAT), found from auroral images. c, d Show the spatial extent of each community, where the dots are the magnetometer locations and the shading is the extent. Color represents the mean MLT of the stations contained within each community, θx¯(t′). e Plots the modularity, Q, (blue line) and the random phase surrogate (black line). f Plots the normalized number of connections, α(t′), both within the nightside (solid blue) and within the SCW (dashed blue), as well as their surrogates (solid and dashed black, respectively, both near-zero throughout). The right ordinate plots (negative) SML (red).The proliferation of space objects is a rapidly increasing source of artificial night sky brightnessby M Kocifaj, F Kundracik, J C Barentine, in Monthly Notices of the Royal Astronomical SocietyScientists reported new research results suggesting that artificial objects in orbit around the Earth are brightening night skies on our planet significantly more than previously understood.The research finds that the number of objects orbiting Earth could elevate the overall brightness of the night sky by more than 10 percent above natural light levels across a large part of the planet. This would exceed a threshold that astronomers set over 40 years ago for considering a location “light polluted.”“Our primary motivation was to estimate the potential contribution to night sky brightness from external sources, such as space objects in Earth’s orbit,” said Miroslav Kocifaj of the Slovak Academy of Sciences and Comenius University in Slovakia, who led the study. “We expected the sky brightness increase would be marginal, if any, but our first theoretical estimates have proved extremely surprising and thus encouraged us to report our results promptly.”The work is the first to consider the overall impact of space objects on the night sky rather than the effect of individual satellites and space debris affecting astronomers’ images of the night sky. The team of researchers, based at institutions in Slovakia, Spain and the US, modelled the space objects’ contribution to the overall brightness of the night sky, using the known distributions of the sizes and brightnesses of the objects as inputs to the model.The study includes both functioning satellites as well as assorted debris such as spent rocket stages. While telescopes and sensitive cameras often resolve space objects as discrete points of light, low-resolution detectors of light such as the human eye see only the combined effect of many such objects. The effect is an overall increase in the diffuse brightness of the night sky, potentially obscuring sights such as the glowing clouds of stars in the Milky Way, as seen away from the light pollution of cities.“Unlike ground-based light pollution, this kind of artificial light in the night sky can be seen across a large part of the Earth’s surface,” explained John Barentine, Director of Public Policy for the International Dark-Sky Association and a study co-author. “Astronomers build observatories far from city lights to seek dark skies, but this form of light pollution has a much larger geographical reach.”Astronomers have expressed unease in recent years about the growing number of objects orbiting the planet, particularly large fleets of communications satellites known informally as ‘mega-constellations’.In addition to crowding the night sky with more moving sources of artificial light, the arrival of this technology increases the probability of collisions among satellites or between satellites and other objects, generating further debris. Recent reports sponsored by the US National Science Foundation and the United Nations Office for Outer Space Affairs identified mega-constellations as a threat to the continued utility of astronomy facilities on the ground and in low-Earth orbit. In the UK the Royal Astronomical Society has established several working groups to understand the impact of mega-constellations on optical and radio astronomical facilities used by scientists.The results published today imply a further brightening of the night sky proportional to the number of new satellites launched and their optical characteristics in orbit. Satellite operators like SpaceX have recently worked to lower the brightness of their spacecraft through design changes. Despite these mitigating efforts though, the collective effect of a sharp increase in the number of orbiting objects stands to change the experience of the night sky for many across the globe.The researchers hope that their work will change the nature of the ongoing dialog between satellite operators and astronomers concerning how best to manage the orbital space around the Earth.“Our results imply that many more people than just astronomers stand to lose access to pristine night skies,” Barentine said. “This paper may really change the nature of that conversation.”Upcoming EventsApr 6–8 Improving Space Operations Workshop 2021 (ISOW 2021)Apr 13 APSCC 2021 Webinar SeriesApr 14 GeoIgnite 2021 — Canada’s National Geospatial & Location Technology ConferenceApr 20 APSCC 2021 Webinar SeriesApr 26 Small Satellites 2021 (Virtual Conference)Apr 27 APSCC 2021 Webinar SeriesApr 28 Military Space Situational Awareness 2021 (Virtual Conference)MISC — @NASA — @Commercial_Crew — @NatureAstronomySubscribe to Paradigm!Medium. Twitter. Telegram. Telegram Chat. Reddit. LinkedIn.Main sourcesResearch articlesNature AstronomyThe Astrophysical JournalScience DailySpace NewsST/ Hubble spots double quasars in merging galaxies was originally published in Paradigm on Medium, where people are continuing the conversation by highlighting and responding to this story.

Read full