Space: The Final Frontier

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New space wars are starting. At least Soviet era has some cool mysterious stories, this is just another US-China cockfight 

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Which alien stars can see Earth?

A new catalogue identifies thousands of nearby stars that could spot Earth’s transit across our Sun.

US astronomers have identified over a thousand nearby star systems that would have been in the right position to view Earth – only visible to them as it passes in front of our Sun – over the past 5,000 years. All of the stars are within 100 parsecs (or 326 light-years) of us. Human-made radio waves have already reached 75 of these star systems.

A total of 3,343 exoplanets have been discovered by observing the dimming of a star’s light when a planet passes in front of it. Astronomers have previously identified other stars that would be in the right position to spot Earth in this way, but a paper published in Nature expands and focuses this list by taking the past movements of stars into account.

“We wanted to know which stars have had the right vantage point to see Earth as it blocks the Sun’s light,” explains Lisa Kaltenegger, a professor of astronomy at Cornell University and author on the paper.

“And because stars move in our dynamic cosmos, this vantage point is gained and lost.”

In the past 5,000 years, the researchers found that 1,715 star systems could have spotted Earth. Another 319 stars will be able to view Earth during the next 5,000 years.

The researchers used data from the European Space Agency’s Gaia telescope to determine how stars had moved over time.

“Gaia has provided us with a precise map of the Milky Way galaxy,” says Jackie Faherty, senior scientist at the American Museum of Natural History and co-author on the paper. “This allowed us to look backwards and forward in time, and to see where stars had been located and where they are going.”

https://cosmosmagazine.com/space/astronomy/which-alien-stars-can-see-earth/

 

 

 

Edited June 27, 2021 by CaaC (John)

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NASA’s Search for Life: Astrobiology in the Solar System and Beyond

Are we alone in the universe? So far, the only life we know of is right here on Earth. But here at NASA, we’re looking.    

NASA is exploring the solar system and beyond to help us answer fundamental questions about life beyond our home planet. From studying the habitability of Mars, probing promising “oceans worlds,” such as Titan and Europa, to identifying Earth-size planets around distant stars, our science missions are working together with a goal to find unmistakable signs of life beyond Earth (a field of science called astrobiology).  

Through the study of astrobiology, NASA invests in understanding the origins, evolution, and limits of life on Earth. This work has been important in shaping ideas about where to focus the search for life efforts. As NASA explores the solar system, our understanding of life on Earth and the potential for life on other worlds has changed alongside the many discoveries. The study of organisms in extreme environments on Earth, from the polar plateau of Antarctica to the depths of the ocean, have highlighted that life as we know it is highly adaptable, but not always easy to find. The search for life requires great care and is based in the knowledge we gain by studying life on Earth through the lens of astrobiology. If there's something out there, we may not yet know how to recognize it. 

Dive into the past, present, and future of NASA’s search for life in the universe.  

Past Missions   

Viking 1 and 2  

Over 45 years ago, the Viking Project found a place in history when it became the first U.S. mission to land a spacecraft safely on the surface of Mars.   

Viking 1 and 2, each consisting of an orbiter and a lander, were NASA’s first attempt to search for life on another planet and thus the first mission dedicated to astrobiology. The mission’s biology experiments revealed unexpected chemical activity in the Martian soil but provided no clear evidence for the presence of living microorganisms near the landing sites.   

Galileo  

NASA’s Galileo mission orbited Jupiter for almost eight years and made close passes by all its major moons. Galileo returned data that continues to shape astrobiology science –– particularly the discovery that Jupiter’s icy moon Europa has evidence of a subsurface ocean with more water than the total amount of liquid water found on Earth. These findings also expanded the search for habitable environments outside of the traditional “habitable zone” of a system, the distance from a star at which liquid water can persist on the surface of a planet. 

Cassini  

For more than a decade, the Cassini spacecraft shared the wonders of Saturn and its family of icy moons –– taking us to astonishing worlds and expanding our understanding of the kinds of worlds where life might exist. 

For the first time, astrobiologists were able to see through the thick atmosphere of Titan and study the moon’s surface, where they found lakes and seas filled with liquid hydrocarbons. Astrobiologists are studying what these liquid hydrocarbons could mean for life’s potential on Titan. Cassini also witnessed icy plumes erupting from Saturn’s small moon Enceladus. When flying through the plumes, the spacecraft found evidence of saltwater and organic chemicals. This raised questions about whether habitable environments could exist beneath the surface of Enceladus.   

Spirit and Opportunity Mars Exploration Rovers  

NASA’s twin Mars Exploration Rovers, Spirit and Opportunity, launched towards Mars in 2003 in search of answers about the history of water on Mars. Originally a three-month prime mission, both robotic explorers far outlasted their original missions and spent years collecting data at the surface of Mars.     

Spirit and Opportunity were the first mission to prove liquid water, a key ingredient for life, had once flowed across the surface of Mars. Their findings shaped our understanding of Mars’ geology and past environments and importantly suggested Mars’ ancient environments may once have been suitable for life.  

Kepler and K2  

NASA’s first planet-hunting mission, the Kepler Space Telescope, paved the way for our search for life in the solar system and beyond. An important part of Kepler’s work was the identification of Earth-size planets around distant stars.  

After nine years in deep space, collecting data that indicate our sky to be filled with billions of hidden planets – more planets even than stars – the space telescope retired in 2018. Kepler left a legacy of more than 2,600 exoplanet discoveries, many of which could be promising places for life.  

Spitzer  

Over its sixteen years in space, the Spitzer Space Telescope evolved into a premier tool for studying exoplanets, using its infrared view of the universe. Spitzer marked a new age in planetary science as one of the first telescopes to directly detect light from the atmospheres of planets outside the solar system, or exoplanets. This enabled scientists to study the composition of those atmospheres and even learn about the weather on these distant worlds.  

Spitzer’s infrared instruments allowed scientists to peer into cosmic regions that are hidden from optical telescopes, including dusty stellar nurseries, the centers of galaxies, and newly forming planetary systems. Spitzer’s infrared eyes also enabled astronomers to see cooler objects in space, like failed stars (brown dwarfs), extrasolar planets, giant molecular clouds, and organic molecules that may hold the secret to life on other planets.  

Current Missions  

Hubble  

Since it launched in 1990, the Hubble Space Telescope has made immense contributions to astrobiology. Astronomers used Hubble to make the first measurements of the atmospheric composition of extrasolar planets, and Hubble is now vigorously characterizing exoplanet atmospheres with constituents such as sodium, hydrogen, and water vapor. Hubble observations are also providing clues about how planets form, through studies of dust and debris disks around young stars.  

Not all of Hubble’s contributions involve distant targets. Hubble has also been used to study bodies within the solar system, including asteroids, comets, planets, and moons, such as the intriguing ocean-bearing icy moons Europa and Ganymede. Hubble has provided invaluable insight into life’s potential in the solar system and beyond.  

MAVEN  

NASA’s atmosphere-sniffing Mars Atmosphere and Volatile Evolution (MAVEN) mission launched in November 2013 and began orbiting Mars roughly a year later. Since that time, the mission has made fundamental contributions to understanding the history of the Martian atmosphere and climate.     

Astrobiologists are working with this atmospheric data to better understand how and when Mars lost its water and identifying periods in Mars’ history when habitable environments were most likely to exist at the planet’s surface.  

Mars Odyssey  

For two decades, NASA’s Mars Odyssey – the longest-lived spacecraft at the Red Planet – has helped locate ice, assess landing sites, and study the planet’s mysterious moons.    

Odyssey has provided global maps of chemical elements and minerals that make up the surface of Mars. These detailed maps are used by astrobiologists to determine the evolution of the Martian environment and its potential for life.  

Mars Reconnaissance Orbiter  

NASA's Mars Reconnaissance Orbiter (MRO) is on a search for evidence that water persisted on the surface of Mars for a long period of time. While other Mars missions have shown that water flowed across the surface in Mars' history, it remains a mystery whether water was ever around long enough to provide a habitat for life.  

Data from MRO is essential to astrobiologists studying the potential for habitable environments on past and present Mars. Additionally, these studies are important in building climate models for Mars, and for use in comparative planetology studies for the potential habitability of exoplanets that orbit distant stars.     

Curiosity Mars Rover  

The Curiosity Mars rover is studying whether Mars ever had environments capable of supporting microbial life. In other words, its mission is to determine whether the planet had all of the ingredients life needs – such as water, carbon, and a source of energy – by studying its climate and geology.   

It’s been nearly nine years since Curiosity touched down on Mars in 2012, and the robot geologist keeps making new discoveries. Curiosity provided evidence that freshwater lakes filled Gale Grater billions of years ago. Lakes and groundwater persisted for millions of years and contained all the key elements necessary for life, demonstrating Mars was once habitable. 

TESS Mission  

The Transiting Exoplanet Survey Satellite (TESS) is the next step in the search for planets outside of our solar system, including those that could support life. Launched in 2018, TESS is on a mission to survey the entire sky and is expected to discover and catalogue thousands of exoplanets around nearby bright stars.  

To date, TESS has discovered more than 120 confirmed exoplanets and more than 2,600 planet candidates. The planet-hunter will continue to find exoplanets targets that NASA’s upcoming James Webb Space Telescope will study in further detail.  

Perseverance Mars Rover  

NASA’s newest robot astrobiologist, the Perseverance Mars rover, touched down safely on Mars on February 18, 2021, and is kicking off a new era of exploration on the Red Planet. Perseverance will search for signs of ancient microbial life, which will advance the agency’s quest to explore the past habitability of Mars.    

What really sets this mission apart is that the rover has a drill to collect core samples of Martian rock and soil, and will store them in sealed tubes for pickup by a future Mars Sample Return mission that would ferry them back to Earth for detailed analysis.   

Upcoming Missions  

James Webb Space Telescope  

The James Webb Space Telescope (Webb), slated to launch in 2021, will be the premier space-based observatory of the next decade. Webb is a large infrared telescope with a 6.5-meter primary mirror.   

Webb observations will be used to study every phase in the history of the universe, including planets and moons in our solar system, and the formation of distant solar systems potentially capable of supporting life on Earth-like exoplanets. The Webb telescope will also be capable of making detailed observations of the atmospheres of planets orbiting other stars, to search for the building blocks of life on Earth-like planets beyond our solar system.  

Europa Clipper Mission  

Jupiter’s moon Europa may have the potential to harbor life. The Europa Clipper mission will conduct detailed reconnaissance of Europa and investigate whether the icy moon could harbor conditions suitable for life. Targeting a 2024 launch, the mission will place a spacecraft in orbit around Jupiter in order to perform a detailed investigation of Europa –– a world that shows strong evidence for an ocean of liquid water beneath its icy crust.    

Europa Clipper is not a life-detection mission, though it will investigate whether the icy moon, with its subsurface ocean, has the capability to support life. Understanding Europa’s habitability will help scientists better understand how life developed on Earth and the potential for finding life beyond our planet.  

Dragonfly Mission to Titan  

The Dragonfly mission will deliver a rotorcraft to visit Saturn’s largest and richly organic moon, Titan. Slated for launch in 2027 and arrival in 2034, Dragonfly will sample and examine dozens of promising sites around Saturn’s icy moon and advance our search for the building blocks of life.     

This revolutionary mission will explore diverse locations to look for prebiotic chemical processes common on both Titan and Earth. Titan is an analog to the very early Earth and can provide clues to how prebiotic chemistry under these conditions may have progressed.  

Nancy Grace Roman Telescope  

Slated to launch in the mid-2020s, the Roman Space Telescope will have a field of view that is 200 times greater than the Hubble infrared instrument, capturing more of the sky with less observing time. In addition to ground-breaking astrophysics and cosmology, the primary instrument on Roman, the Wide Field Instrument, has a rich menu of exoplanet science. It will perform a microlensing survey of the inner Milky Way that will reveal thousands of worlds orbiting within the habitable zone of their star and farther out while providing an additional bounty of more than 100,000 transiting exoplanets. 

The mission will also be fitted with “starglasses,” a coronagraph instrument that can block out the glare from a star and allow astronomers to directly image giant planets in orbit around it. The coronagraph will provide the first in-space demonstration of technologies needed for future missions to image and characterize smaller, rocky planets in the habitable zones of nearby stars. Roman coronagraph will make observations that could contribute to the discovery of new worlds beyond our solar system and advance the study of extrasolar planets that could be suitable for life.    

https://www.nasa.gov/feature/nasa-s-search-for-life-astrobiology-in-the-solar-system-and-beyond

 

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Wonders of the Universe: 23 mind-blowing photos from the Astronomy Photographer of the Year 2021 shortlist
See the year's most jaw-dropping images of space.

 

 

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Meet the burrowing space robot that could explore the moons of Jupiter

Researchers were inspired by both the roots of plants and a burrowing sand octopus to develop a robot that NASA want to send into space.

Robots have helped us explore the world, from the ocean’s depths to mountain peaks, and even into outer space. But while researchers have made robots that can swim, run and fly better than their biological counterparts, engineers have struggled to build a bot that can burrow as well as an animal.

To design a device that could navigate the subterranean world, researchers at the University of California and the Georgia Institute of Technology decided to take inspiration from nature.

Instead of using a mechanical drill to overcome the resistant forces in the ground, the team have built a flexible soft robot that works with physics, instead of against it.

 

The soft robot moves through a sandy terrain in several ways. To travel straight down, the robot acts like a plant’s root system, with a tip that extends to push surrounding material out of its way. The team can control the movements of the bot using ‘tendons’ on either side and steering with these enable the robot to make sharp turns along tortuous paths.

To move horizontally through the ground, the robot imitates the burrowing sand octopus: blowing air from its tip in asymmetrical directions to overcome the resistance of the sand and get from A to B. This is referred to as air fluidisation, as it keeps the solid particles of sand moving, much like the particles within a fluid.

“Unlike in a gas or liquid, a symmetric object moving horizontally through a granular media experiences lift. It is simply easier to push the sand up and out of the way than it is to compact it down,” said Dr Nicholas Naclerio, lead author of the research.

“As a result, with only forward airflow, our robot resurfaces. This lift force is countered by adding a downward airflow to the robot. The asymmetric combination of both forward and downward airflow enables controllable horizontal burrowing.”

Though the robot developed by the team for this new research is just 6cm in diameter, with a tip able to extend to 1m, researchers say they have designed bots as small as 2mm and as large as 70m.

The combination of tip extension and air fluidisation technology was tested in a sandy environment, but the team are now working with NASA to develop a robot that can burrow on the surface of the Moon, or be sent to explore far away bodies such as Enceladus, a moon of Jupiter.

“Soft robots are unproven in space, but we believe they could be powered by a small tank of compressed gas, a chemical gas generator, or by collecting gas from the local environment,” explained Naclerio.

“Air fluidisation only works in dry granular media, like sand. However, fluidising with waterworks in damp, or cohesive media, like dirt and clay.

“Tip extension could also be used with other mechanisms, such as drills, to explore other environments.”

https://www.sciencefocus.com/news/meet-the-burrowing-space-robot-that-could-explore-the-moons-of-jupiter/

 

Edited July 1, 2021 by CaaC (John)

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Astronauts install a new solar power array on the ISS during an epic six-hour spacewalk

The new array is half the size of the original one but will generate roughly the same amount of power.

Two astronauts from NASA and the European Space Agency have successfully installed the first of six new solar arrays on the International Space Station (ISS).

The mission is the first step in a programme to increase the power generation capacity of the ISS to meet future demands including Artemis – NASA’s planned crewed mission to the Moon, currently scheduled for 2023.

Some of the original arrays have been in place for 20 years and are showing signs of age. The six new arrays will be installed directly on top of the existing ones and generate roughly the same amount of power despite only being half the size.

FULL REPORT & PHOTOS

Edited July 6, 2021 by CaaC (John)

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Cosmic cloud in galactic ‘no-man’s land’

Astronomers find a mysterious cloud bigger than the Milky Way.

In a first-of-its-kind discovery, US researchers have spotted a cosmic cloud bigger than our own Milky Way, floating alone in a cluster of galaxies tenuously bound together by gravity.

This ‘orphan’ cloud has a mass 10 billion times greater than our own Sun and is made up of searing-hot gas with temperatures up to 10 million degrees Kelvin. It is believed to have been formed within one of the galaxies in the cluster and then stripped out, though researchers are puzzling over how it has survived on its own for so long instead of dissipating.

“This is an exciting and also a surprising discovery,” says Ming Sun, a physicist at the University of Alabama in Huntsville, US.

Sun is the lead author of the new study, published in the Monthly Notices of the Royal Astronomical Society, which describes how the cloud was accidentally found using the European Space Agency’s (ESA) X-ray Multi-Mirror Mission (XMM-Newton), a space observatory currently in orbit around the Earth.

Follow-up observations were made on the ground by the MUSE instrument on the European Southern Observatory’s Very Large Telescope, as well as by Japan’s optical telescope, Subaru.

The optical data confirmed the cloud was located within a cluster – Abell 1367, also known as the Leo Cluster, which is 330 million light-years from Earth and contains more than 70 major galaxies.

“However, the cloud is not associated with any galaxy and is in a ‘galaxy's land’,” explains Sun.

The current temperature of the cloud is between 10,000 to 10 million degrees, Kelvin, while the hot gas of the galaxy cluster reaches temperatures of 100 million Kelvin. This is consistent with the cloud being formed within one of the galaxies, first existing between stars as a gaseous interstellar medium.

Sun and colleagues suggest the cloud was then ripped out, as its host galaxy sped through the hot gas of the cluster at speeds of up to 2000 kilometres per second.

“It is like when your hairs and clothes are flying backwards when you are running forward against a strong headwind,” says Sun. “Once removed from the host galaxy, the cloud is initially cold and is evaporating in the hot intracluster medium, like ice melting in the summer.”

Puzzlingly, this cloud has likely been separated from its host galaxy for hundreds of millions of years, but it hasn’t yet dissipated. The researchers suggest this longevity may be related to its magnetic field, potentially holding the cloud together.

Now that astronomers have spotted this lonely cloud, ripped from its parent, they’ll be searching for more.

“As the first isolated cloud glowing in both the H-alpha spectral line and X-rays in a cluster of galaxies, it shows that the gas removed from galaxies can create clumps in the intracluster medium, and these clumps can be discovered with wide-field optical survey data in the future,” concludes Sun.

https://cosmosmagazine.com/space/astrophysics/cosmic-cloud-in-galactic-no-mans-land/

 

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Australian-led researchers believe they have found evidence for a new type of stellar explosion – a magneto-rotational hypernova – that may solve the mystery of why some of the earliest stars in the universe contain more heavy metals than others.

More than 13 billion years ago, the first generations of stars were made almost entirely of hydrogen and helium, and as they exhausted their fuel and exploded, they cooked up heavier elements that seeded the next stellar generation.

But new research, led by the ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (ASTRO 3D), has identified one such ‘chemically primitive’ star that doesn’t quite match the others. The wonderfully named SMSS J200322.54-114203.3, which orbits in the halo of the Milky Way, contains a much higher ratio of heavy metals, including zinc, uranium, europium and possibly gold, than thought possible for its age.

“The star we’re looking at has an iron-to-hydrogen ratio about 3000 times lower than the Sun, which means it is very rare – what we call an extremely metal-poor star,” says David Yong, an astrophysicist at the Australian National University (ANU) and lead author of the study.

“However, the fact that it contains much larger than expected amounts of some heavier elements means that it is even rarer – a real needle in a haystack.”

Astronomers previously knew that heavy elements could be forged by the collisions between neutron stars during this early epoch of star formation, yet these smash-ups are not enough to explain the ratios seen in SMSS J200322.54-114203.3.

“The extra amounts of these elements had to come from somewhere,” says co-author Chiaki Kobayashi from the University of Hertfordshire in the UK.

In the paper in Nature, the team calculated that these elements could be produced by a new type of explosion, triggered by the violent collapse of a rapidly spinning star. Called a magneto-rotational hypornova, this event is 10 times more energetic than a typical supernova.

“We calculate that 13 billion years ago, J200322.54-114203.3 formed out of a chemical soup that contained the remains of this type of hypernova,” says Yong. “No one’s ever found this phenomenon before.”

Astronomers have known about hypernovae for decades, but a magneto-rotational hypernova combines rapid rotation and strong magnetism.

Kobayashi explains: “We now find the observational evidence for the first time directly indicating that there was a different kind of hypernova producing all stable elements in the periodic table at once – a core-collapse explosion of a fast-spinning, strongly magnetised massive star. It is the only thing that explains the results.”

The star was first identified by ANU’s SkyMapper survey, with follow-up observations at the ANU 2.3m Telescope at Siding Spring Observatory in NSW and the European Southern Observatory’s Very Large Telescope in Chile.

https://cosmosmagazine.com/space/astrophysics/colossal-cataclysm-may-explain-mystery-star/

 

 

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An algorithm that labels galaxies

A new neural network can speed up galactic classification.

Classifying galaxies currently needs to be done manually, requiring a lot of time from astronomers and citizen scientists. But a team of Australian astrophysicists has now developed a machine-learning algorithm that should speed the process up considerably.

“Galaxies come in different shapes and sizes,” says Mitchell Cavanagh, a PhD candidate at the  University of Western Australia branch of the International Centre for Radio Astronomy Research (ICRAR), and lead author on a paper describing the research, published in Monthly Notices of the Royal Astronomical Society.

“Classifying the shapes of galaxies is an important step in understanding their formation and evolution, and can even shed light on the nature of the Universe itself.”

As telescopes improve, the volume of data on new galaxies is becoming too overwhelming for astronomers to deal with.

“We’re talking several million galaxies over the next few years. Sometimes citizen scientists are recruited to help classify galaxy shapes in projects like Galaxy Zoo, but this still takes time,” says Cavanagh.

Cavanagh and colleagues have addressed this by developing a program based on a convolutional neural network, or CNN. These neural networks are particularly useful for processing visual data, because of the way they layer information.

“Each convolutional layer applies a variety of filters to the image to create feature maps,” says Cavanagh. “Think of Adobe Photoshop, where you might want to sharpen edges or apply a smooth blur.”

“What makes CNN's so versatile is that the filters used to extract these features are not hard-coded at all; in fact, they start off completely random!”

CNN's have previously been used by astronomers to classify galaxies, but only in binary cases – whether a galaxy is a spiral galaxy or not, for instance. This neural network will use multiclass classification, making it more accurate than existing networks.

“The massive advantage of neural networks is speed,” says Cavanagh. “Using a standard graphics card, we can classify 14,000 galaxies in less than three seconds.”

The network has been trained on galaxy data generated by people. This means it will not necessarily be more accurate than humans (its overall accuracy is 80%), but it will be much faster.

“This inherent uncertainty is the limiting factor in any AI model trained on labelled data.”

Cavanagh adds that another limiting factor in the network’s accuracy is that galaxies that don’t fit neatly into these categories. “There are many different types (and subtypes!) of galaxies, as the Hubble tuning fork will attest to. Even if we were to group them into overarching categories such as ‘Elliptical’, ‘Lenticular’ or ‘Spiral’, there will almost always be some overlap and some disagreement.

“The biggest barrier with the CNN is accurately classifying irregular galaxies. As the name suggests, this category is necessarily broad, covering everything from odd-shaped clumps to galaxies undergoing massive tidal disruption. It’s no surprise then that the CNN misclassifies many irregulars.”

He points out that the data they’ve trained the galaxies on under-represents these irregular galaxies, which may also affect the network’s accuracy.

While the neural network can speed things up, it relies on data from citizen science astronomy projects.

“Citizen science initiatives are extremely useful for astronomers, as the success of Galaxy Zoo and its sequel Galaxy Zoo 2 have shown. The ICRAR-led AstroQuest citizen science project also aims to help inspect many tens of thousands of galaxies,” says Cavanagh.

“Another often-overlooked benefit of citizen science is the availability of large-population statistics. It’s then easy to see which galaxies contributors found easy to classify (nearly unanimous selections) and which were harder to classify (broad spread of selections). The harder-to-classify galaxies can then be selected for more targeted analysis. It’s highly likely that such initiatives will continue as more large-scale surveys go online.”

CNN's could be used in other fields if given big enough datasets to train with.

“CNN's need not just apply to optical images of galaxies, they can just as easily work with radio images too, which will be useful with the imminent arrival of the Square Kilometre Array (SKA),” says Cavanagh.

“CNN's will play an increasingly important role in the future of data processing, especially as fields like astronomy grapple with the challenges of big data.”

https://cosmosmagazine.com/technology/ai/an-algorithm-that-labels-galaxies/

 

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See the First Images NASA’s Juno Took As It Sailed by Ganymede

This image of Ganymede was obtained by the JunoCam imager during Juno’s June 7, 2021, flyby of the icy moon.

Credits: NASA/JPL-Caltech/SwRI/MSSS

Full image and caption

The spacecraft flew closer to Jupiter’s largest moon than any other in more than two decades, offering dramatic glimpses of the icy orb.

The first two images from NASA Juno’s June 7, 2021, flyby of Jupiter’s giant moon Ganymede have been received on Earth. The photos – one from the Jupiter orbiter’s JunoCam imager and the other from its Stellar Reference Unit star camera – show the surface in remarkable detail, including craters, clearly distinct dark and bright terrain, and long structural features possibly linked to tectonic faults.

“This is the closest any spacecraft has come to this mammoth moon in a generation,” said Juno Principal Investigator Scott Bolton of the Southwest Research Institute in San Antonio. “We are going to take our time before we draw any scientific conclusions, but until then we can simply marvel at this celestial wonder.”

FULL REPORT

 

Edited July 12, 2021 by CaaC (John)

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40-Year Mystery Solved: Source of Jupiter’s X-Ray Flares Uncovered

A puzzler about the gas giant’s intense northern and southern lights has been deciphered.

Planetary astronomers combined measurements taken by NASA’s Juno spacecraft orbiting Jupiter, with data from ESA’s (the European Space Agency’s) Earth-orbiting XMM-Newton mission, to solve a 40-year-old mystery about the origins of Jupiter’s unusual X-ray auroras. For the first time, they have seen the entire mechanism at work: The electrically charged atoms or ions, responsible for the X-rays are “surfing” electromagnetic waves in Jupiter’s magnetic field down into the gas giant’s atmosphere.

A paper on the study was published on July 9 in the journal Science Advances.

Auroras have been detected on seven planets in our solar system. Some of these light shows are visible to the human eye; others generate wavelengths of light we can only see with specialized telescopes. Shorter wavelengths require more energy to produce. Jupiter has the most powerful auroras in the solar system and is the only one of the four giant planets with an aurora that has been found to emit X-rays.

Planetary astronomers have been fascinated with Jupiter’s X-ray auroral emission since its discovery four decades ago because it was not immediately clear how the energy required to produce it is generated. They knew these surprising Jovian northern and southern lights are triggered by ions crashing into Jupiter’s atmosphere. But until now scientists had no idea how the ions responsible for the X-ray light show are able to get to the atmosphere in the first place.

At Earth, auroras are usually visible only in a belt surrounding the magnetic poles, between 65 and 80 degrees latitude. Beyond 80 degrees, auroral emission disappears because the magnetic field lines leave Earth and connect to the magnetic field in the solar wind, which is the constant flux of electrically charged particles ejected by the Sun. These are called open field lines, and in the traditional picture, Jupiter’s and Saturn’s high-latitude polar regions are not expected to emit substantial auroras, either.

However, Jupiter’s X-ray auroras are different. They exist poleward of the main auroral belt and pulsate, and those at the north pole often differ from those at the south pole. These are typical features of a closed magnetic field, where the magnetic field line exits the planet at one pole and reconnects with the planet at the other. All planets with magnetic fields have both open and closed field components.

Scientists studying the phenomena turned to computer simulations and found that the pulsating X-ray auroras could be linked to closed magnetic fields that are generated inside Jupiter and then stretch out millions of miles into space before turning back. But how to prove the model was viable?

The study authors turned to data acquired by both Juno and XMM-Newton from July 16 to 17, 2017. During the two-day span, XMM-Newton observed Jupiter continuously for 26 hours and saw X-ray aurora pulsating every 27 minutes.

At the same time, Juno had been travelling between 62 and 68 Jupiter radii (about 2.8 to 3 million miles, or 4.4 to 4.8 million kilometres) above the planet’s pre-dawn area. This was exactly the region that the team’s simulations suggested was important for triggering the pulsations, so they searched the Juno data for any magnetic processes that were occurring at the same rate.

They found that fluctuations of Jupiter’s magnetic field caused the pulsating X-ray auroras. The outer boundary of the magnetic field is struck directly by the particles of the solar wind and compressed. These compressions heat ions that are trapped in Jupiter’s extensive magnetic field, which are millions of miles away from the planet’s atmosphere.

This triggers a phenomenon called electromagnetic ion cyclotron (EMIC) waves, in which the particles are directed along the field lines. Guided by the field, the ions ride the EMIC wave across millions of miles of space, eventually slamming into the planet’s atmosphere and triggering the X-ray auroras.

“What we see in the Juno data is this beautiful chain of events. We see the compression happen, we see the EMIC wave triggered, we see the ions, and then we see a pulse of ions travelling along the field line,” said William Dunn of the Mullard Space Science Laboratory, University College London, and a co-author of the paper. “Then, a few minutes later, XMM sees a burst of X-rays.”

Now that the missing piece of the process has been identified for the first time, it opens up a wealth of possibilities for where it could be studied next. For example, at Jupiter, the magnetic field is filled with sulfur and oxygen ions being emitted by the volcanoes on the moon Io. At Saturn, the moon Enceladus jets water into space, filling Saturn’s magnetic field with water group ions.

More About the Mission

JPL, a division of Caltech in Pasadena, California, manages the Juno mission for the principal investigator, Scott J. Bolton, of the Southwest Research Institute in San Antonio. Juno is part of NASA’s New Frontiers Program, which is managed at NASA’s Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington. Lockheed Martin Space in Denver built and operates the spacecraft.

https://www.nasa.gov/feature/jpl/40-year-mystery-solved-source-of-jupiter-s-x-ray-flares-uncovered

 

[CaaC (John)+]

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Nasa set for an attempt to fix Hubble's trouble

Nasa will attempt to fix a problem that has stopped the Hubble telescope from being used for astronomy.

Nasa will attempt to fix a problem that has stopped the Hubble telescope from being used for astronomy.

It's the worst glitch in years to hit the venerated observatory.

An onboard computer halted on 13 June, leading to the science instruments being put in "safe mode" - where all non-essential systems are shut down.

Now, the possible origin of the malfunction has been traced to a control unit that supplies electricity to the failed computer.

Ground controllers will begin switching over to backup hardware on Thursday, in an effort to get one of the most important scientific tools in history up and running again.

Although astronomy observations have been suspended since June, Nasa says the telescope itself and the science instruments are healthy.

Officials said the possible cause of the fault lies with a Power Control Unit (PCU). This ensures a steady voltage supply to the payload computer's hardware.

It's the payload computer that stopped functioning back in June.

The possible diagnosis concerning the PCU came from information gleaned when engineers attempted to restart and reconfigure the payload computer and the backup computer.

Experts have already tried to send ground commands to reset the PCU, but this effort has failed.

Nasa management has now given approval for the Hubble recovery team to switch over to a backup PCU.

This is the operation set to begin on Thursday; if successful, it will take several days to completely return the observatory to normal science operations.

Launched aboard the space shuttle Discovery in 1990, Hubble has taken over 1.5 million observations. These have been used to publish some 18,000 scientific papers.

It has contributed to some of the most significant discoveries in astronomy. One of these was the observation that the expansion of the Universe was accelerating. This in turn led to a conclusion that most of the cosmos was made up of mystery "stuff" called dark energy.

A successor to Hubble, the James Webb Space Telescope (JWST), is scheduled to launch later this year. But many astronomers hope that the two will be able to operate alongside each other - at least for some period of time.

https://www.bbc.co.uk/news/science-environment-57844454

 

[CaaC (John)+]

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Galactic fireworks go off

New images reveal violent births in stellar nurseries.

An international team of astronomers has snapped stunning images of “galactic fireworks”, capturing stellar nurseries as they give birth to new stars.

These images focus on galaxies close to the Milky Way and show their different components in distinct colours, including the locations of clouds of gas and dust where infant stars are igniting. They were taken as part of the PHANGS (Physics at High Angular Resolution in Nearby GalaxieS) survey, which is using both ground and space-based telescopes to peer into these violent nurseries.

“By combining observations from some of the world’s most powerful telescopes, we can examine the galactic regions where star formation is happening, compared to where it is expected to happen,” says team member Rebecca McElroy from the University of Sydney.

“This will give us a chance to better understand what triggers, boosts or holds back the birth of new stars.”

These particular images were snaps by the European Southern Observatory’s Very Large Telescope (VLT), using a powerful instrument called the Multi-Unit Spectroscopic Explorer (MUSE). MUSE is an integral field spectrograph: it collects light across the visible spectrum, resulting in a “3D” image where each pixel contains multiple wavelengths of light.

As part of PHANGS, MUSE has collected 15 million spectra of various galactic regions, spanning 30,000 clouds of warm gas where stars could form.

Further images from PHANGS have been taken by the Atacama Large Millimetre/submillimetre Array (ALMA), which looks at a different region of the electromagnetic spectrum and enables researchers to survey clouds of colder gas; so far, it has observed 100,000 gas regions across 90 galaxies.

“By combining these observations with those from ALMA, we’re able to see newborn stars while they’re still surrounded by the blanket of gas they’ve formed from,” says Brent Groves, from the University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR).

“The resulting images are absolutely stunning – they allow us a spectacularly colourful insight into the stellar nurseries of our neighbouring galaxies.”

Further observations planned with NASA’s James Webb Space Telescope will allow astronomers to scrutinise star-forming processes into infra-red light.

https://cosmosmagazine.com/space/astrophysics/galactic-fireworks-go-off/

 

Edited July 18, 2021 by CaaC (John)

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Jet black: ‘little’ black holes emulate their supergiant siblings

Jet activity in radio galaxy mirrors that of the far larger Messier 87 galaxy.

Just like younger siblings, ‘little’ black holes do their best to act the same as big ones, according to a study published in Nature Astronomy.

An international team, including researchers from CSIRO, used the Event Horizon Telescope – the telescope that captured the first Messier 87 black hole image – to image the heart of the Centaurus A radio galaxy – one of closest radio galaxies to Earth  – which has a central, supermassive black hole.

The ‘little’ black hole has a mass of about 55 million suns, which puts it between the mass of Messier 87 (6.5 billion suns) and the centre of the Milky Way (four million suns). It behaves like Messer 87, albeit on a smaller scale.

The team was able to make this observation because the Event Horizon Telescope caught the galaxy in unprecedented detail – with all its jets and glory.

Supermassive black holes feed off gas and dust that gets pulled in by their immense gravitational pull. Most of the matter is ‘consumed’ but some of it escapes just before capture and is blown out into space – these are called jets. They are very energetic, but little is known about how they are launched.

“This allows us for the first time to see and study an extragalactic radio jet on scales smaller than the distance light travels in one day,” says astronomer Michael Janssen from the Max Planck Institute for Radio Astronomy, Germany, and Radboud University, Netherlands. “We see up close and personally how a monstrously gigantic jet launched by a supermassive black hole is being born.”

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Read More: Astronomers find ‘Goldilocks’ black hole

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Despite its small size, the Centaurus A black hole produced jets – outflows of matter – that were similar to Messier 87, except they were on a smaller scale. Only the outer edges of the jet seemed to emit radiation, which challenges some theoretical models.

“Now we are able to rule out theoretical jet models that are unable to reproduce this edge-brightening,” says Matthias Kadler, professor for astrophysics at the University of Würzburg in Germany. “It’s a striking feature that will help us better understand jets produced by black holes.”.

Using these observations of the jets’ launch locations helped the astronomers estimate the position of the black hole. This will help them get better future images, now they know where to look.

“These data are from the same observing campaign that delivered the famous image of the black hole in Messier 87,” says Heino Falcke, professor for astrophysics at Radboud University, Netherlands. “The new results show that the Event Horizon Telescope provides a treasure trove of data on the rich variety of black holes and there is still more to come.”.

https://cosmosmagazine.com/space/astronomy/jet-black-little-black-holes-emulate-their-supergiant-siblings/

 

[CaaC (John)+]

Moon-forming disc detected around another world.

A distant ring of gas and dust offers new clues about solar system formation...

https://cosmosmagazine.com/space/astrophysics/moon-forming-disc-detected-around-another-world/

[CaaC (John)+]

Hubble returns to full-service observations and releases new images.

NASA Hubble Space Telescope is back in business, exploring the universe near and far. The service instruments have returned to fully operational, following recently from a computer anomaly that suspended the telescope observations for more than a month.

https://www.nasa.gov/feature/goddard/2021/hubble-returns-to-full-science-observations-and-releases-new-images

 

Edited July 24, 2021 by CaaC (John)

[CaaC (John)+]

Water in Ganymeta's atmosphere

Hubble Space Telescope finds evidence for water around Jupiter's largest moon.

https://cosmosmagazine.com/space/astronomy/water-in-ganymedes-atmosphere/

[CaaC (John)+]

[nudge+]

Apollo 11 and also Mission Control: The Unsung Heroes of Apollo are both on Netflix now, with a lot of archival footage and new interviews. Well worth a watch.

[CaaC (John)+]

First light detected from behind a black hole.

X-rays bouncing off a black hole's disc confirm Einstein's predictions.

 

 https://cosmosmagazine.com/space/astrophysics/first-light-detected-from-behind-a-black-hole/

 

[CaaC (John)+]

 

[nudge+]

Both Roscosmos and NASA streams are live now. About 45 minutes until docking.

[nudge+]

Docking successful!

 

[CaaC (John)+]

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Australia joins star wars

Federal government looks to counter space jams and attacks.

In the face of emerging space threats, the Australian government is looking for a new ground-based Space Electronic Warfare capability.

It will stop jamming or spoofing attacks on Australia’s space-based assets and, being electronic, will not create dangerous space debris. ‘Hard kill’ options such as physically knocking out a satellite are increasingly dangerous to all space users because of the space junk they leave behind, so ‘soft kill’ methods are the main focus for most countries.

Defence Minister Peter Dutton said on Thursday that Defence Project 9358, as part of the Australian Defence Force’s approach to space control, “seeks to detect and deter attempts to interfere with, or attack, our use of the space domain” in the face of “emerging space threats to Australia’s free use of the space domain.

“Defence will explore options for a Space Electronic Warfare capability and provide recommendations for a decision by the government.”

The announcement came on the same day that space analyst Malcolm Davis told the Australian Government Solicitor’s Office and the Australian Society for Technology and the Law that it was clear that China and Russia were ramping up their military space capabilities, particularly their anti-satellite technology. He also said that North Korea could potentially go rogue and wipe out the world’s space-based communications abilities.

“Space gives them potential to create all sorts of mischief,” he said, describing a scenario where North Korea launched a warhead into geostationary orbit (GEO) and exploded it.

“It creates a whole amount of shrapnel,” he said. “You’re taking out GEO access for decades, if not longer.”

Another attack could come by detonating a nuclear warhead in the radioactive Van Allen belts, dragging the radiation into a lower altitude so it would start irradiating satellites in low Earth orbit.

Dr Davis, a senior analyst in defence strategy and capability at the Australian Strategic Policy Institute, has previously outlined the possibility of space wars. Anti-satellite technology already in operation can spoof, jam, dazzle or hack satellites, and Dr Davis said if Australia’s access to space is denied through such an attack we will be left “deaf, dumb and blind”.

“We cannot talk to our forces, coordinate amongst them or with allies, understand the battlespace, or fight in a manner that maximises chances of success and minimises risks of failure,” he said.

While Australia, which has recently invested billions in space capabilities and created a space division within the military, has not yet decided what the Electronic Warfare capability would look like, the United States has started using a new ground-based communications jammer.

The Counter Communications System Block 10.2 (CCS) is a transportable satellite dish. While the Australian version could be more defensive in nature – interrupting enemy attacks – the CCS is also an offensive weapon that can block enemies from accessing their own military communications satellites.

https://cosmosmagazine.com/space/exploration/australia-joins-star-wars/

 

Edited July 29, 2021 by CaaC (John)

[nudge+]

Damn... So there were issues with Nauka after docking, as its thrusters started firing unexpectedly. Knocked ISS a few degrees off position, that had to be countered through Mission Control. Emergency protocols were activated, SpaceX Crew Dragon was powered up in case the astronauts needed to evacuate. All under control now.