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Darja
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« Reply #2400 on: Sep 03, 2020, 03:02 AM »

Scientists detect mysterious ‘intermediate mass’ black hole

on September 3, 2020
By Agence France-Presse

Scientists announced Wednesday the discovery of a black hole — the oldest ever detected — that shouldn’t even exist according to the current understanding of cosmic monsters so dense not even light can escape their gravitational pull.

Born of a merger between two other black holes, GW190521 weighs in at 142 times the mass of our Sun and is the first “intermediate mass” black hole ever observed, two consortiums of some 1,500 scientists reported in a pair of studies.

“This event is a door opening into the cosmic process for the formation of black holes,” co-author Stavros Katsanevas, an astrophysicist at the European Gravitational Observatory, said in an online press conference.

“It is a whole new world.”

A so-called stellar-class black hole forms when a dying star collapses, and is typically three to ten solar masses in size.

Supermassive black holes found at the centre of most galaxies, including the Milky Way, range from millions to billions of solar masses.

Up to now, black holes with mass 100 to 1,000 times that of our Sun had never been found.

“This is the first evidence of a black hole in this mass range,” said co-author Michaela, an astrophysicist at the University of Padova and a member of the Europe-based Virgo Collaboration.

“It may lead to a paradigm shift in the astrophysics of black holes.”

The findings, she added, support the idea that supermassive black holes could be formed through the repeated merger of these mid-sized bodies.

What scientists actually observed were gravitational waves produced more than seven billion years ago when GW190521 was formed by the collision of two smaller black holes of 85 and 65 solar masses.

When they smashed together, eight solar masses worth of energy was released, creating one of the most powerful events in the Universe since the Big Bang.

Gravitational waves were first measured in September 2015, earning the lead researchers a physics Nobel two years later.

Albert Einstein anticipated gravitational waves in his general theory of relativity, which theorized that they spread through the Universe at the speed of light.

– Challenge to current models –

GW190521 was detected on May 21, 2019 by three interferometers, which can measure a change thousands of times smaller than an atomic nucleus as gravitational waves pass Earth.

According to current knowledge, the gravitational collapse of a star cannot form black holes in the range of 60 to 120 solar masses because — at that size — the stars are completely blown apart by the supernova explosion that accompanies collapse.

And yet, the two black holes that gave rise to GW190521 were both in the range.

“This event is a challenge for the current models of black hole formation,” said Mapelli.

It is also a hint of how much is still not known.

“This detection confirms that there is a vast universe that has remained invisible to us,” said Karan Jani, an astrophysicist with the Nobel-winning LIGO gravitational wave experiment.

“We have very limited theoretical and observational understanding of this elusive class of intermediate black hole.”

But the very fact it could be detected is itself remarkable.

“Our ability to find a black hole a few hundred kilometers-wide from half-way across the Universe is one of the most striking realizations of this discovery,” Jani added.

The two studies were published in Physical Review Letters, and Astrophysical Journal Letters.

The LIGO (Laser Interferometer Gravitational-Wave Observatory) consortium is led by scientists at MIT and Caltech, while the Virgo collaboration includes more than 500 scientists across Europe.

© 2020 AFP


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« Reply #2401 on: Sep 04, 2020, 03:22 AM »

NASA’s Mars rover spots a Martian dust devil

By Mike Wehner
BGR
9/4/2020

    NASA’s Curiosity rover managed to capture images showing a dust devil cruising along the dry landscape.
    Dust devils occur when temperature irregularities create vortexes, much like on Earth.
    Mars and Earth are shockingly similar in many ways, in this is a handy reminder of that fact.

We know a lot about Mars thanks to NASA’s Red Planet rovers. The machines have provided us with some of the most stunning glimpses of our planetary neighbor ever, while also revealing many of the planet’s secrets. Thanks to those machines, we know that Mars is a dusty, mostly dry place, and we also know that martian wind can kick up in a hurry.

We’ve seen the evidence of the planet’s incredible wind many times, including the massive dust storm that doomed the Opportunity rover after it blocked out the Sun. Now, in a new update to the Curiosity mission blog, we’re treated to a truly incredible set of images that show a Martian dust devil in action.

Situated in the Gale Crater, Curiosity has been exploring the Mars landscape for many years now. It regularly captures images of its surroundings and beams them back to Earth. These images help the Curiosity team at NASA plan for future travel, but occasionally the images reveal something else. In this case, it’s a swirling torrent of wind sweeping across the dusty terrain.

You have to almost squint to see it, and the fact that the images are in black and white doesn’t necessarily help matters at all, but you can definitely see the mini tornado-like tail of the dust devil cruising along in the distance.

If you’re having trouble seeing it, check out the larger version and open your browser window to full screen. You can see the dust devil, which looks like a white line trailing along in the distance. It’s not exactly a powerful torrent, but it’s enough to carry surface dust high into the air.


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« Reply #2402 on: Sep 05, 2020, 04:09 AM »


The moon is getting rusty due to oxygen stripped from Earth’s atmosphere

An oxidised form of iron was surprisingly common the moon, which may reveal insights about Earth's atmospheric history.

Tibi Puiu
ZME
9/5/2020

With a virtually non-existent atmosphere and no liquid water, you’d think the moon would be the last place you’d find hematite — basically rusted iron that requires the presence of both iron and water. But that’s exactly what researchers have recently discovered at high latitudes on the moon.
Enhaned map of hematite on the moon’s nearside. Credit: Shuai Li.

The reddish dust we all know as rust is essentially a chemical product of the reaction between iron and oxygen. It’s very common on Earth (you can find iron oxides almost everywhere) but since there is no oxygen on the moon, you wouldn’t really expect any hematite. In fact, sample return missions during the Apollo era and subsequent satellite observations have only been able to find pristine metallic iron devoid of any sign of rust.

However, when planetary scientist Shuai Li of the University of Hawaii at Manoa was examining spectral data from NASA’s Moon Mineralogy Mapper (M3), as well as from the Chandrayaan-1 orbiter operated by the Indian Space Research Organization, he noticed signatures typical of hematite.

    “When I examined the M3 data at the polar regions, I found some spectral features and patterns are different from those we see at the lower latitudes or the Apollo samples,” said Li in a statement. “I was curious whether it is possible that there are water-rock reactions on the Moon. After months of investigation, I figured out I was seeing the signature of hematite.”

Researchers had quite a mystery on their hands. Hematite requires both water and oxygen to form. For water, researchers had a hunch. Hematite was most abundant at the lunar poles, where there’s also ice water. But what about the oxygen — where could that come from?

Here too, geography might hold the answer. According to the data analyzed by Li and colleagues, most of the hematite on the lunar surface seems to be distributed on the lunar nearside, which always faces Earth. So the likely culprit was Earthly oxygen.

    “This reminded me of a discovery by the Japanese Kaguya mission that oxygen from Earth’s upper atmosphere can be blown to the lunar surface by solar wind when the Moon is in Earth’s magnetotail. So, Earth’s atmospheric oxygen could be the major oxidant to produce haematite,” Li said.

Map of hematite on the moon. Red corresponds to more hematite. Credit: Shuai Li.

That’s not to say that hematite is absolutely absent from the far-side of the moon — it’s just that much fewer oxidative events were seen there, the researchers added.

    “The tiny amount of water observed at lunar high latitudes may have been substantially involved in the haematite formation process on the lunar far-side, which has important implications for interpreting the observed haematite on some water poor S-type asteroids,” Li said.

Scientists may be able to learn more about how exactly oxidation occurs on the moon when NASA’s ARTEMIS mission return hematite samples from the polar regions. Beyond confirming the source of oxidation for lunar minerals, the sampled hematite could still retain oxygen isotopes from Earth’s ancient atmosphere. This way, scientists can learn more about our planet’s history.

    “This discovery will reshape our knowledge about the Moon’s polar regions,” said Li. “Earth may have played an important role on the evolution of the Moon’s surface.”

The findings appeared in the journal Science Advances.


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« Reply #2403 on: Sep 07, 2020, 03:14 AM »

NASA just spotted a galaxy that looks like a TIE Fighter

By Mike Wehner
ZME
9/7/2020

    Scientists using NASA’s Fermi space telescope have spotted a distant galaxy that looks strangely familiar.
    The galaxy has the appearance of a TIE Fighter, a famous and fictional ship from Star Wars.
    At a distance of 500 million light-years, there’s little chance we’d ever visit, but it still looks cool from a distance.

Most of what I know about space I learned from Star Wars. Okay, that’s not true, but most of what I wish existed in space is definitely based on the Star Wars universe. So, you can imagine my excitement when NASA posted an image of a distant galaxy called TXS 0128+554. It’s not the contents of the galaxy itself that excites me — though perhaps there are abundant alien worlds and a struggle between an empire and some rebels going on there — but rather its appearance.

I mean, just look at it. That’s most definitely a TIE Fighter. NASA agrees, and in a new blog post, the space agency offers an explanation for why the galaxy appears as it does in these radio images.

The galaxy, which was discovered using the Fermi Gamma-ray Space Telescope, emits radio waves in a very distinct pattern. The would-be “wings” of the TIE Fighter are believed to be the result of energy spewing from the center of the galaxy, which is likely a black hole.

“After the Fermi announcement, we zoomed in a million times closer on the galaxy using the VLBA’s radio antennas and charted its shape over time,” Matthew Lister, lead author of a study of the galaxy published in The Astrophysical Journal. “The first time I saw the results, I immediately thought it looked like Darth Vader’s TIE fighter spacecraft from ‘Star Wars: Episode IV – A New Hope.’ That was a fun surprise, but its appearance at different radio frequencies also helped us learn more about how active galaxies can change dramatically on decade time scales.”

While the images from Fermi do a good job of showing the shape of the radio emissions, NASA’s own computer renderings offer us a new look, and it explains why one “wing” of the galaxy appears larger to us than the other.

“The real-world universe is three-dimensional, but when we look out into space, we usually only see two dimensions,” Daniel Homan, co-author of the study, explains. “In this case, we’re lucky because the galaxy is angled in such a way, from our perspective, that the light from the farther lobe travels dozens of more light-years to reach us than the light from the nearer one. This means we’re seeing the farther lobe at an earlier point in its evolution.”

Unfortunately (for me), this awesome galaxy isn’t exactly nearby. It sits roughly 500 million light-years from Earth, which means visiting it will be out of the question for the foreseeable future. Bummer.


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« Reply #2404 on: Sep 08, 2020, 02:57 AM »

Scientists say time travel via wormholes might actually be possible

By Mike Wehner
BGR
9/8/2020

    Scientists have found a way to send humans through wormholes and keep them alive for the journey.
    The theory assumes a lot about various physics models that remain unproven.
    If you were to travel through one, time would pass by thousands of years for everyone else except for you.

If you’re trying to come up with the holy grail of scientific achievement it’s pretty much a tossup between discovering the secret to immortality and developing time travel. We’re certainly not nearing an age where humans can live as long as they choose, but with regards to time travel, a rather tantalizing discovery has just been made.

As a new paper by researchers at Princeton explains, time travel may indeed be possible under certain conditions, and if specific physics models are accurate. The only catch? It requires a wormhole in space that would allow a human to survive the journey, and we could only go forward in time, not backward. Still, that’s enough to get me out of the year 2020, and that’s all I really care about at this point.

As you might expect, the research paper gets into some pretty intense math and theoretical setups that might not actually be possible. It relies heavily on the Randall-Sundrum model of physics, primarily because the Standard Model only allows for microscopic wormholes to exist, and if we want to travel through time, we’re going to need a wormhole large enough that a person could pass through it and come out the other end in one piece.

The Randall-Sundrum model allows a bit more flexibility when it comes to these specific physics calculations, but the modified Randall-Sundrum II model is even more flexible. The fact that a person would be subjected to intense gravity when passing through a wormhole is the biggest hurdle, and the larger the wormhole is, the more forgiving the gravitational tidal forces would be.

“Better wormholes are possible by using a Randall Sundrum II model with a U(1) gauge field,” the researchers explain. “This model allows for large enough wormholes that could be traversed humanely, i.e. surviving the tidal forces. Using them, one could travel in less than a second between distant points in our galaxy. A second for the observer that goes through the wormhole. It would be tens of thousands of years for somebody looking from the outside.”

A wormhole is like a doorway connecting two points in space. You pass through it, and suddenly you’ve traveled a much greater distance than would have been possible using conventional means. The catch is that while your experience passing through the wormhole feels almost instant, huge stretches of time will pass for the rest of the cosmos.

Again, this is all theoretical,  but based on the conditions of the wormhole, you could pass through it, and, from an outsider’s point of view, by the time you appeared on the other side you might possibly be the last human alive in the entire universe.

It’s some very intense stuff, and right now it only works on paper. Still, if there were a wormhole in front of me right now that let me skip 2020, I might be willing to go the extra hundred thousand years, too.


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« Reply #2405 on: Sep 09, 2020, 01:23 AM »

Hubble captures gorgeous, delicate supernova blast wave

By Mike Wehner
BGR
9/9/2020

    NASA’s Hubble telescope spotted a wispy orange ribbon in space, but it’s actually the destructive blast wave of a supernova.
    The supernova is located in the Cygnus constellation and is roughly 2,400 light-years from Earth.
    Hubble has now spent over three decades imaging the cosmos and shows no signs of slowing down.

NASA’s Hubble Space Telescope has captured many images that look so incredible you almost can’t believe they’re real. The image above definitely falls into that category, especially because at first glance it’s almost impossible to tell what it is. A delicate orange ribbon drifting through space? That doesn’t really exist… does it? Apparently it does, only it’s not a ribbon, it’s the incredibly powerful blast wave from a dying star.

As NASA explains in a new blog post, what we’re seeing here is really just a fraction of the overall picture. This tiny sliver of the blast wave sits some 2,400 light-years from Earth. That’s a safe enough distance that we’re not in danger, but close enough that Hubble can show us the beautiful, destructive force from afar.

Supernovas occur when stars of certain sizes die. They exhaust their fuel and collapse in on themselves, leading to a massive explosion. The star that created the supernova that produced this particular blast wave was a real monster. NASA estimates that it was around 20 times as massive as our own Sun. The explosion itself occurred somewhere between 10,000 and 20,000 years ago, according to NASA scientists.

“Since then, the remnant has expanded 60 light-years from its center,” NASA explains. “The shockwave marks the outer edge of the supernova remnant and continues to expand at around 220 miles per second. The interaction of the ejected material and the low-density interstellar material swept up by the shockwave forms the distinctive veil-like structure seen in this image.”

The star that went boom is part of the Cygnus constellation. The massive collection of stars takes up 36 times as much room in the night sky as the Moon. That’s big, but it’s not nearly as large as the largest constellations like Hydra and Ursa Major. Nevertheless, you’d have to squint pretty hard to see this blast wave from your back yard. Just kidding, please don’t try to see this. You definitely won’t be able to.

It’s pretty wild to think that the Hubble Space Telescope has been orbiting Earth for over 30 years already, yet continues to return stunning images like the one you see above. Imaging technology has come a long way since the spacecraft was first launched — a few upgrades and some maintenance along the way have kept it tip-top shape — but you have to wonder what incredible things we’ll be able to see once NASA’s James Webb Space Telescope finally takes to the skies… whenever that may be.


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« Reply #2406 on: Sep 10, 2020, 03:06 AM »


Rogue Planets Could Outnumber Stars in the Milky Way

We might have to revise the commonly accepted image of planets orbiting a parent star.

Rob Lea
ZME
9/10/2020

Our galaxy is teeming with rogue planets either torn from their parent stars by chaotic conditions or born separate from a star. These orphan planets could be discovered en masse by an outcoming NASA project — Nancy Grace Roman Space Telescope.

The Milky Way is home to a multitude of lonely drifting objects, galactic orphans — with a mass similar to that of a planet — separated from a parent star. These nomad planets freely drift through galaxies alone, thus challenging the commonly accepted image of planets orbiting a parent star. ‘Rogue planets’ could, in fact, outnumber stars in our galaxy, a new study published in the Astronomical Journal indicates.

    “Think about how crazy it is that there could be an Earth, a Mars, or a Jupiter floating all alone through the galaxy. You would have a perfect view of the night sky but stuck in an eternal night,” lead author of the study, Samson Johnson, an astronomy graduate student at The Ohio State University, tells ZME Science. “Although these planets could not host life, it is quite a place to travel to with your imagination. The possibility of rogue planets in our galaxy had not occurred to me until coming to Ohio State.”

This artist’s conception illustrates a Jupiter-like planet alone in the dark of space, floating freely without a parent star. (NASA)

Up to now, very few very of these orphan planets have actually been spotted by astronomers, but the authors’ simulations suggest that with the upcoming launch of NASA’s Nancy Grace Roman Space Telescope in the mid-2020s, this situation could change. Maybe, drastically so.

    “We performed simulations of the upcoming Nancy Grace Roman Space Telescope (Roman) Galactic Exoplanet Survey to determine how sensitive it is to microlensing events caused by rogue planets,” Johnson says. “Roman will be good at detecting microlensing events from any type of ‘lens’ — whether it be a star or something else — because it has a large field of view and a high observational cadence.”

The team’s simulations showed that Roman could spot hundreds of these mysterious rogue planets, in the process, helping researchers identify how they came to wander the galaxy alone and indicating how great this population could be in the wider Universe.

Rogue by Name, Rogue by Nature: Mysterious and Missing

Thus far, much mystery surrounds the process that sees these planets freed from orbit around a star. The main two competing theories suggest that these stars either are thrown free of their parent star, or form in isolation. Each process would likely lead to rogue planets with radically different qualities.

    “The first idea suggests that rogue planets form like planets in the Solar System, condensing from the protoplanetary disk that accompanies stars when they are born,” Johnson explains. “But as the evolution of planetary systems can be chaotic and messy, members can be ejected from the system leading to most likely rogue planets with masses similar to Mars or Earth.”

 Johnson goes on to offer an alternative method of rogue planet formation that would see them form in isolation, similar to stars that form from giant collapsing gas clouds. “This formation process would likely produce objects with masses similar to Jupiter, roughly a few hundred times that of the Earth.”

    “This likely can’t produce very low-mass planets — similar to the mass of the Earth. These almost certainly formed via the former process,” adds co-author Scott Gaudi, a professor of astronomy and distinguished university scholar at Ohio State. “The universe could be teeming with rogue planets and we wouldn’t even know it.”

The question is if these objects are so common, why have we spotted so few of them? “The difficulty with detecting rogue planets is that they emit essentially no light,” Gaudi explains. “Since detecting light from an object is the main tool astronomers use to find objects, rogue planets have been elusive.”

Astronomers can use a method called gravitational microlensing to spot rogue planets, but this method isn’t without its challenges, as Gaudi elucidates:

    “Microlensing events are both unpredictable and exceedingly rare, and so one must monitor hundreds of millions of stars nearly continuously to detect these events,” the researcher tells ZME Science. “This requires looking at very dense stellar fields, such as those near the centre of our galaxy. It also requires a relatively large field of view.”

Additionally, as the centre of the Milky Way is highly obscured by requiring us to look at it in the near-infrared region of the electromagnetic spectrum — a task that is extremely difficult as the Earth’s atmosphere makes the sky extremely bright in near-infrared light.

    “All of these points argue for a space-based, high angular resolution, wide-field, near-infrared telescope,” says Gaudi. “That’s where Roman — formally the Wide Field InfraRed Survey Telescope (WFIRST) — comes in.”

Nancy Grace Roman Space Telescope (and Einstein) to the Rescue!

The Roman telescope — named after Nancy Grace Roman, NASA’s first chief astronomer, who paved the way for space telescopes focused on the broader universe–will launch in the mid-2020s. It is set to become the first telescope that will attempt a census of rogue planets — focusing on planets in the Milky Way, between our sun and the centre of our galaxy, thus, covering some 24,000 light-years.

The team’s study consisted of simulations created to discover just how sensitive the Roman telescope could be to the microlensing events that indicate the presence of rogue planets, finding in the process, that the next generation space telescope was 10 times as sensitive as current Earth-based telescopes. This difference in sensitivity came as a surprise to the researchers themselves. “Determining just how sensitive Roman is was a real shock,” Johnson says. “It might even be able to tell us about moons that are ejected from planetary systems! We also, found a new ‘microlensing degeneracy’ in the process of the study — the subject another paper that will be coming out shortly.”

Johnson’s co-author Gaudi echoes this surprise. “I was surprised that Roman was sensitive to rogue planets with mass as low as that of Mars and that the signals were so strong,” the researcher adds. “I did not expect that before we started the simulations.”

The phenomenon that Roman will exploit to make its observations stems from a prediction made in Einstein’s theory of general relativity, that suggests that objects with mass ‘warp’ the fabric of space around them. The most common analogy used to explain this phenomenon is ‘dents’ created in a stretched rubber sheet by placing objects of varying mass upon it. The heavier the object — thus the greater the mass — the larger the dent.

Watch: https://youtu.be/6vVetE5cEMA

This warping of space isn’t just responsible for the orbits of planets, it also curves the paths of light rays, the straight paths curving as they pass the ‘dents’ in space. This means that light from a background source is bent by the effect of the mass of a foreground object. The effect has recently been used to spot a distant Milky Way ‘look alike’. But in that case, and in the case of many gravitational lensing events, the intervening object was a galaxy, not a rogue planet, and thus was a much less subtle, more long-lasting, and thus less hard to detect effect than ‘microlensing’ caused by a rogue planet.
This animation shows how gravitational microlensing can reveal island worlds. When an unseen rogue planet passes in front of a more distant star from our vantage point, light from the star bends as it passes through the warped space-time around the planet. The planet acts as a cosmic magnifying glass, amplifying the brightness of the background star. (NASA’s Goddard Space Flight Center/CI Lab)

    “Essentially, a microlensing event happens when a foreground object — in this case, a rogue planet — comes into very close alignment with a background star. The gravity of the foreground object focuses light from the background star, causing it to be magnified,” Gaudi says. “The magnification increases as the foreground object comes into alignment with the background star, and then decreases as the foreground object moves away from the background star.”

As Johnson points out, microlensing is an important and exciting way to study exoplanets — planets outside the solar system — but when coupled with Roman, it becomes key to spotting planetary orphans.

“Roman really is our best bet to find these objects. The next best thing would be Roman 2.0 — with a larger field of view and higher cadence,” the researcher tells ZME, stating that rogue planets are just part of the bigger picture that this forthcoming space-based telescope could allow us to see. “I’m hoping to do as much work with Roman as possible. The next big project is determining what Roman will be able to teach us about the frequency of Earth-analogs — Earth-mass planets in the habitable zones of Sun-like stars.”

Original Research

Johnson. S. A., Penny. M, Gaudi. B. S, et al, ‘Predictions of the Nancy Grace Roman Space Telescope Galactic Exoplanet Survey. II. Free-floating Planet Detection Rates*,’ The Astronomical Journal, [2020].


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« Reply #2407 on: Sep 11, 2020, 02:58 AM »


Why is Neptune blue?

Clouds of methane absorb red wavelengths, but reflect mostly bluish light.

Tibi Puiu
ZME
9/11/2020

Out of all the planets in the solar system, Neptune is the one that looks most peaceful. When seen through a telescope, the eighth and most distant planet from the sun appears sky-blue or as a uniform, peaceful ocean world that would have made the Roman god of the sea proud.

In reality, Neptune is anything but peaceful and its atmosphere is actually mainly made of three gases: hydrogen (80%), helium (19%), and methane (1%).

It’s actually clouds of methane gas that are responsible for the distant planet’s blue marble appearance. Despite the fact it makes up a relatively tiny proportion of Neptune’s atmosphere, methane absorbs red wavelengths of light and reflects blue light outward.

A distant blue gem

Neptune is the only planet in the solar system that isn’t visible to the naked eye. As such, it was among the last to be discovered in 1846 by Johann Galle, based on mathematical predictions made by Urbain Le Verrier.

But during these initial observations, astronomers had no idea what Neptune looked like.

The planet, which is about four times larger than Earth, was first visited by a spacecraft in 1989 when NASA’s Voyager 2 made a flyby. Voyager beamed back images showing Neptune’s ocean-like hue for the first time. It was really a stroke of luck that Neptune was so aptly named when astronomers could not have known that the planet is all blue.

Similarly to Uranus, Neptune is one-fifth hydrogen and helium by mass. The bulk of the planet’s mass, however, is owed to heavier molecules such as ammonia, methane, carbon, oxygen, and water.

Despite their similarities in size and composition, Neptune and Uranus are distinctly colored. This is explained by different chemical components in each of the planets’ upper atmospheres, particularly in the global cloud deck.

Neptune’s clouds are known to vary with altitude, just like on Earth. Methane clouds condense in the highest layers of the planet’s atmosphere due to frigidly cold temperatures. Further down, there may be clouds of hydrogen sulfide, ammonium sulfide, ammonia, and water. The blue-toned methane isn’t evenly distributed; ten to a hundred times more methane, ethane, and ethyne can be found at Neptune’s equator than at its poles.

Being present in the outermost layer of the atmosphere, the most important compound that influences the color of both planets’ atmospheres is methane. The greenhouse gas absorbs red light at wavelengths of 600 billionths of a meter, reflecting back bluer light. Uranus, however, is more azure, blue-green in appearance due to an additional chromophore that Neptune seems to lack. This particular chromophore hasn’t been identified yet so the true nature of Neptune’s color is still a mystery.


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« Reply #2408 on: Sep 12, 2020, 03:39 AM »

Jupiter’s moons are warmer than they should be, but why?

By Mike Wehner
BGR
9/12/2020

    New research shows that Jupiter’s moons may be keeping each other warm thanks to the effects of gravity.
    The tidal forces each moon applies to the others are keeping them warmer than they would otherwise be.
    Jupiter’s moon Europa has a subsurface ocean that may hold life.

Jupiter is well known for being the might, gassy, “king” of the planets. It’s huge, and it has a whole bunch of moons orbiting it as well. In fact, the gas giant has almost 80 worlds orbiting it, ranging from small to massive. The weird thing about them is that they appear to be quite a bit warmer than they really should be, but why?

New research published in Geophysical Research Letters suggests that the moons themselves are responsible for their own warming, or at least they’re responsible for warming each other. It might sound odd, but when you consider the effects of gravity, it actually makes perfect sense.

The focus of the new study is on a phenomenon known as tidal heating. Simply put, tidal heating refers to the gravitational forces of the moons pulling on each other as they pass by in orbit around their host planet. Just like Earth’s Moon tugs on our own planet to produce tides, the gravitational pull of Jupiter’s moons are acting on one another and imparts energy which results in heat.

Jupiter’s moon Europa is believed to have a subsurface ocean deep beneath its frozen crust. Without tidal heating, such a thing may not be possible based on how far away Jupiter is from the Sun. It certainly affects water worlds like Europa, but it may have the same effect on rock planets.

“Maintaining subsurface oceans against freezing over geological times requires a fine balance between internal heating and heat loss, and yet we have several pieces of evidence that Europa, Ganymede, Callisto and other moons should be ocean worlds,” Antony Trinh, co-author of the research, said in a statement. “Io, the moon closest to Jupiter, shows widespread volcanic activity, another consequence of tidal heating, but at a higher intensity likely experienced by other terrestrial planets, like Earth, in their early history. Ultimately, we want to understand the source of all this heat, both for its influence on the evolution and habitability of the many worlds across the solar system and beyond.”

The researchers ran models to verify this theory. They found that Jupiter alone couldn’t be responsible for the tidal forces, and that factoring the moons themselves into the model was the only thing that produced enough tidal force to result in the warming.

At present, Jupiter’s Europa is one of the main candidates in our search for extraterrestrial life within our own solar system. It’s possible, scientists believe, that life is thriving in the subsurface ocean on the moon, and future missions may be able to prove that true.


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« Reply #2409 on: Sep 14, 2020, 03:04 AM »

Andromeda’s sphere of influence is much larger than anyone thought

By Mike Wehner
BGR
9/14/2020

    NASA scientists have detected a massive halo of plasma surrounding the nearby Andromeda galaxy.
    The halo, a massive orb of influence stretching deep into space, reaches halfway to our own Milky Way galaxy.
    Eventually, Andromeda and the Milky Way are expected to merge into one galaxy.

We hear a lot about the Milky Way and that makes sense since it’s the galaxy we happen to live in, but not far away is another galaxy that is just as interesting as our own. It’s the Andromeda galaxy, and despite being 2.5 million light-years away (“not far away” is relative when it comes to deep space), there’s a lot it could teach us about itself and perhaps even our own galaxy.

Now, in a new study published in The Astrophysical Journal, NASA scientists have spotted what they are calling a “halo” around Andromeda. The halo, which is more like a huge bloom of plasma, stretches 1.3 million light-years into space. That’s roughly halfway to our own galaxy, which is an impressive feat.

We often think of galaxies as self-contained collections of stars, planets, and gasses, but that’s simply not the case. The effects of a galaxy extend far beyond their outer edge. In fact, the line between the edge of a galaxy and empty space is so blurred that there’s hardly a real “edge” at all. In the case of Andromeda, the halo of plasma is so massive that it absolutely dwarfs the size of the galaxy itself.

“Understanding the huge halos of gas surrounding galaxies is immensely important,” Samantha Berek of Yale University, co-author of the research, said in a statement. “This reservoir of gas contains fuel for future star formation within the galaxy, as well as outflows from events such as supernovae. It’s full of clues regarding the past and future evolution of the galaxy, and we’re finally able to study it in great detail in our closest galactic neighbor.”

But how did NASA scientists detect this massive halo from such a distance? Well, they sort of cheated. Instead of trying to detect the plasma itself, the researchers observed the light of quasars situated much farther away than Andromeda itself. They measured the light of the quasars in relation to how close they appeared to Andromeda, from our perspective here on Earth. The thicker the plasma halo is, the more light from the quasar would be absorbed before it could reach the Earth, giving the researchers a bunch of new data points — 43 to be exact — with which to work.

“Previously, there was very little information—only six quasars—within 1 million light-years of the galaxy. This new program provides much more information on this inner region of Andromeda’s halo,” J. Christopher Howk, co-author of the work, explains. “Probing gas within this radius is important, as it represents something of a gravitational sphere of influence for Andromeda.”


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« Reply #2410 on: Sep 15, 2020, 02:39 AM »

Scientists find gas on Venus linked to life on Earth

on September 15, 2020
By Agence France-Presse

The atmosphere of Venus contains traces of phosphine gas — which on Earth can be attributed to living organisms — scientists said on Monday, in a fresh insight into conditions on our nearest planetary neighbor.

Conditions on Venus are often described as hellish with daytime temperatures hot enough to melt lead and an atmosphere comprised almost entirely of carbon dioxide.

A team of experts used telescopes in Hawaii and Chile’s Atacama Desert to observe Venus’ upper cloud deck, around 60 kilometers (45 miles) from the surface.

They detected traces of phosphine, a flammable gas that on Earth often occurs from the breakdown of organic matter.

Writing in Nature Astronomy, the team stressed the presence of phosphine did not prove the presence of life on Venus.

However, as the clouds swirling about its broiling surface are highly acidic and therefore destroy phosphine very quickly, the research did show that something was creating it anew.

The researchers conducted several modeling calculations in a bid to explain the new phosphine production.

They concluded that their research provided evidence “for anomalous and unexplained chemistry” on Venus.

Lead author Jane Greaves, from Cardiff University’s School of Physics and Astronomy told AFP that the presence of phosphine alone was not proof of life on Earth’s nextdoor neighbor.

“I don’t think we can say that — even if a planet was abundant in phosphorus, it might lack something else important to life — some other element, or conditions might be too hot, too dry,” she said.

Greaves added that it was the first time phosphine had been found on a rocky planet other than Earth.

– ‘Exciting’ –

Reacting to the study, Alan Duffy, an astronomer from Swinburne University and Lead Scientist of The Royal Institution of Australia, said it while it was tempting to believe that the phosphine was produced by lifeforms, “we have to rule out all possible other non-biological means of producing it”.

He called the finding “one of the most exciting signs of the possible presence of life beyond Earth I have ever seen”.

Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate, which has conducted several fly-bys of Venus, called Monday’s research “intriguing”.

Venus, which rotates in the opposite direction to Earth and where a day lasts 243 times longer, is a subject of intense interest among astronomers.

It is so close and of such similar size to our home planet that some experts believe it serves as a warning of the dangers of runaway climate change.

Previous studies have unearthed tantalizing clues suggesting Venus has active volcanoes, including signs of recent lava flows.

© 2020 AFP


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« Reply #2411 on: Sep 16, 2020, 03:07 AM »


Venus discovery ‘most significant development yet’ in search for extraterrestrial life: NASA chief

on September 16, 2020
By Agence France-Presse

The atmosphere of Venus contains a gas that on Earth can be attributed to living organisms, scientists said Monday, a discovery the head of NASA called “the most significant development yet” in the hunt for extraterrestrial life.

Conditions on our planetary neighbour are often described as hellish with daytime temperatures hot enough to melt lead and an atmosphere comprised almost entirely of carbon dioxide.

However, a team of experts detected traces of phosphine, a flammable gas that on Earth often occurs from the breakdown of organic matter.

They used telescopes in Hawaii and Chile’s Atacama Desert to observe Venus’ upper cloud deck, around 60 kilometres (45 miles) from the surface.

Writing in Nature Astronomy, the team stressed the presence of phosphine did not prove the presence of life on Venus.

But, as the clouds swirling about its broiling surface are highly acidic and therefore destroy phosphine very quickly, the research did show that something was creating it anew.

The researchers conducted several modelling calculations in a bid to explain the new phosphine production.

They concluded that their research provided evidence “for anomalous and unexplained chemistry” on Venus.

Lead author Jane Greaves, from Cardiff University’s School of Physics and Astronomy told AFP that the presence of phosphine alone was not proof of life on Earth’s next door neighbour.

“I don’t think we can say that — even if a planet was abundant in phosphorus, it might lack something else important to life — some other element, or conditions might be too hot, too dry,” she said.

Greaves added that it was the first time phosphine had been found on a rocky planet other than Earth.

The breakthrough was hailed by NASA administrator Jim Bridenstine, who tweeted, “it’s time to prioritize Venus.”

“Life on Venus? The discovery of phosphine, a byproduct of anaerobic biology, is the most significant development yet in building the case for life off Earth,” he wrote.

The bulk of current efforts to look for past extraterrestrial life focus on Mars, which is known to have once contained all the necessary ingredients to support carbon-based organisms.

The US and China recently sent rovers to the Red Planet, while the UAE sent an atmospheric probe.

‘Exciting’

Reacting to the study, Alan Duffy, an astronomer from Swinburne University and Lead Scientist of The Royal Institution of Australia, said it while it was tempting to believe that the phosphine was produced by lifeforms, “we have to rule out all possible other non-biological means of producing it”.

He called the finding “one of the most exciting signs of the possible presence of life beyond Earth I have ever seen”.

Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate, which has conducted several fly-bys of Venus, called Monday’s research “intriguing”.

“As with an increasing number of planetary bodies, Venus is proving to be an exciting place of discovery, though it had not been a significant part of the search for life,” he tweeted.

He added that the planet was the focus of two out of four of NASA’s next four candidate missions under its Discovery Program, as well as Europe’s proposed EnVision mission, in which NASA is a partner.

Venus, which rotates in the opposite direction to Earth and where a day lasts 243 times longer, is a subject of intense interest among astronomers.

It is so close and of such similar size to our home planet that some experts believe it serves as a warning of the dangers of runaway climate change.

Previous studies have unearthed tantalising clues suggesting Venus has active volcanoes, including signs of recent lava flows.


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« Reply #2412 on: Sep 17, 2020, 02:41 AM »

Venus is a ‘Russian Planet’ according to Russia’s space chief

By Mike Wehner
BGR
9/17/2020

    Venus was recently revealed to hold a biosignature in its atmosphere that may indicate the presence of life in some form.
    Russia, which previously landed probes on Venus, has declared Venus to be “a Russian Planet.”
    Both NASA and Russia’s Roscosmos are dedicated to exploring Venus in the near future.

When the United States landed humans on the moon in the late 1960s they planted an American flag there. The country was in the middle of the space race with the USSR, and it made sense that the US would put a big exclamation point on its achievement by slapping a flag on the lunar surface. The US didn’t try to lay claim to the entire Moon, of course, but it was a highly symbolic move.

Now, Russia is doing something similar… only this time it’s with Venus. NASA hasn’t done a whole lot when it comes to exploring Venus, but Russia did land multiple probes on the planet as recently as 1984. In the wake of the news that biosignatures may indicate life in some form exists on the planet, Russia’s space boss has declared that Venus is a “Russian planet,” whatever that means.

Russia has been planning a mission to return to Venus for some time. The mission, which is still in the planning stages, is likely to be conducted with some help from NASA. However, speaking with reporters this week, Roscosmos boss Dmitry Rogozin said that another mission is also likely, and it will be conducted without help from other countries.

“Resuming Venus exploration is on our agenda,” Rogozin said. “Firstly, we have the ‘Venera-D’ project in cooperation with the Americans. We are also considering our own mission to Venus. We think that Venus is a Russian planet, so we shouldn’t lag behind. Projects of Venus missions are included in the united government program of Russia’s space exploration for 2021-2030.”

Russia’s state-owned TASS news agency reported the news, stating that in May, Lev Zeleny of the Russian Space Research Institute said that the country is already planning “at least three research vehicles” to be sent to Venus, though the type of research those vehicles would be conducted was not specified.

The surface of Venus is an incredibly hostile place, at least when it comes to life and machinery. The probes that Russia sent to the surface didn’t last long and were dead within a half-hour in some cases. None of the machines lasted longer than a couple of hours under the intense pressure and heat of the surface.

Obviously, technology has improved since those probes were launched, and it’s possible that a lander could survive for significantly longer while returning valuable data. Nevertheless, it’s going to be interesting to see if we have a new “space race” on our hands when it comes to exploring Venus.


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« Reply #2413 on: Sep 18, 2020, 02:46 AM »

Astronomers just found a first-of-its-kind planet

By Mike Wehner
BGR
9/18/2020

    Researchers have spotted a planet orbiting a white dwarf star just 80 light-years from Earth.
    White dwarf stars don’t typically have planets orbiting them due to the nature of how stars live and die.
    The planet in this case is many times the size of the star itself, making the pair an even odder couple.

There are many different kinds of stars in the cosmos. Some are much larger than others, and some burn brighter and hotter than their peers. Over time, stars enter different stages of their own life cycles, and for many stars, becoming a white dwarf is the end of the line. By this point in a star’s life, it has typically destroyed just about everything around it, but researchers just made a discovery that contradicts all of that.

A white dwarf called WD 1856 sits roughly 80 light-years from Earth. That’s just a stone’s throw in cosmic terms, and when researchers gazed at it they spotted something they didn’t expect. It appears as though WD 1856 is being orbited by a massive planet that simply shouldn’t be there. A study on the subject was published in the journal Nature.

As far as astronomers know, white dwarfs begin their lives as much larger stars. As they burn up all of their fuel, they balloon in size, turning into what scientists call a red giant star. At this stage, it envelops anything in its immediate vicinity, including planets, moons, and asteroids. Eventually, the red giant burns up its fuel and collapses. The result is a glowing husk of a star known as a white dwarf.

Now, if this is what happened to WD 1856, then there shouldn’t really be anything orbiting closely, much less a mega-huge planet that is actually larger than the star itself by a large margin. The planet is roughly the size of Jupiter, according to NASA, and it orbits its tiny host star once every 34 hours, which is incredibly fast.

“WD 1856 b somehow got very close to its white dwarf and managed to stay in one piece,” Andrew Vanderburg, lead author of the study, said in a statement. “The white dwarf creation process destroys nearby planets, and anything that later gets too close is usually torn apart by the star’s immense gravity. We still have many questions about how WD 1856 b arrived at its current location without meeting one of those fates.”

It’s an incredible discovery, and while the planet, in this case, may not be ideal when it comes to searching for life, it’s possible that other planets orbiting white dwarfs do indeed have the right conditions for life to take root and even thrive. Once dismissed by astronomers searching for life in space, white dwarfs now much be considered a viable candidate for hosting planets capable of supporting living organisms


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« Reply #2414 on: Sep 19, 2020, 03:40 AM »


11 mind-blowing facts about Jupiter

Jupiter is at least twice as massive as all other planets in the solar system combined. But that’s not all…

Tibi Puiu
BGR
9/19/2020

Jupiter is named after the Roman king of the gods for good reason. It’s the largest planet in the solar system and has more moons than any other planet. But that’s not all. Read on for more facts about one of the most amazing planets in the solar system.

1. Jupiter is the king of planets by mass

Everyone’s learned at school that Jupiter is the largest planet in the solar system. However, this is a bit of an understatement. Jupiter is by far the most massive cosmic body in the solar system, being 2.5 times more massive than all other planets combined. It is nearly 318 times more massive than Earth and it would take 11 Earths lined up next to each to match Jupiter’s diameter.

2. Its Great Red Spot is actually a planetary-sized storm that has been raging on for centuries
Image of Jupiter’s Great Red Spot processed using low resolution (wide angle) orange, green, and blue filtered images overlaying high resolution (narrow angle) orange images taken by Voyager 2 on July 8 1979. Credit: NASA/JPL-Caltech/Kevin M. Gill.

In 1665, famed Italian astronomer Giovanni Cassini observed a huge blemish south of Jupiter’s equator. This ‘Great Red Spot’, as it’s still called today, has been the subject of contention among astronomers for centuries. Some have proposed that the feature, which is large enough to contain 2-3 planets the size of Earth’s diameter, is a huge storm. This is indeed the case, NASA scientists found after the Voyager 1 mission completed a flyby of the planet in 1979.

Scientists confirmed that the Great Red Spot is an extremely persistent anticyclonic storm, fueled by Jupiter’s turbulent and fast-moving atmosphere.

The red spot spins anticlockwise and takes six Earth days to rotate completely. However, it remains a mystery why this stormy region is red. One possible explanation is the presence of red organic compounds.

The Great Red Spot might disappear in the next few centuries, though. During Cassini’s observations, the size of the spot is estimated to have been 40,000 km, whereas today it is about half as large. However, astronomers are fairly confident a new giant red spot will appear somewhere else on Jupiter’s surface, due to the planet’s atmospheric dynamics.

3. The first astronomers to track Jupiter were Babylonians

It’s no secret that the ancient Babylonians were skilled mathematicians. For instance, they understood the Pythagorean theorem nearly 4,000 years ago, or more than a millennium before Pythagoras himself was born.

Their mathematical prowess naturally extended to astronomy, regularly employing arithmetic to catalog the movements of celestial bodies and improve their astronomical predictions.

Mathieu Ossendrijver of Germany’s Humboldt University of Berlin spent no less than 13 years studying 2,400-year-old tablets that contained what he described as a “small bunch of four weird trapezoid computations.” He later found that the trapezoids encoded aspects of Jupiter’s motion, including its appearances on the horizon.

4. Jupiter has the shortest day of all planets, despite its hefty size

For all its monstrous size and mass, you’d think Jupiter would be slow to rotate around its axis. However, it’s the fastest spinning planet in the solar system, with a rotational velocity of 45,300 km/h.

As such, a day on Jupiter only lasts 9 hours and 55 minutes. A year, however, is much longer — Jupiter orbits the sun every 11.8 Earth years.

What’s more, due to this rapid rotation, the planet has an oblate shape with flattened poles and a bulging equator. Its powerful rotation is also responsible for the next point.

5. Jupiter has the strongest magnetic field of any planet in the solar system

Like Earth, Jupiter’s core is made of active, swirling molten material whose motion generates a magnetic field — and a very powerful one to boot. According to measurements performed by NASA, Jupiter’s magnetic field is at least 14 times stronger than Earth’s, making it the most powerful in the solar system.

6. Jupiter has a thin ring system
 
This wouldn’t be a list of facts about Jupiter without mentioning its rings. Unlike Saturn’s more iconic rings, Jupiter’s are very faint and made of dust rather than ice.

For centuries, these rings were too faint for astronomers to notice. Imagine everyone’s surprise when NASA’s Voyager 1 spacecraft beamed back images of Jupiter’s rings in 1979. The three-ring system begins some 92,000 kilometers above Jupiter’s cloud tops and stretches out to more than 225,000 km from the planet. They are between 2,000 to 12,500 kilometers thick.

7. Jupiter has 79 moons and counting

Until recently, Jupiter was widely regarded as the planet of the solar system with the most natural satellites. That’s until 2019, when astronomers affiliated with the Carnegie Institution for Science in Washington DC raised the total number of moons around Saturn to 82, beating Jupiter’s 79.

Almost all of Jupiter’s moons are tiny, with a diameter of less than 10 kilometers. This is also one of the reasons why astronomers are constantly finding new moons around both Jupiter and Saturn.

Jupiter does have some moons that stand out more. These four major moons are collectively known as Galilean Moons. They are Io, Europa, Ganymede, and Callisto. Ganymede, with a diameter of 5,262 km, is actually the largest moon in the solar system. And, who knows, perhaps Jupiter might regain its title as the most moon-populated planet as scientists believe it may have as many as 200 natural satellites orbiting it.

8. And some of these moons may actually be capable of harboring life

The Voyager and Galileo missions that sent spacecraft to Jupiter and its moons found that Europa, one of the biggest moons in the solar system, has a subsurface liquid ocean covered in thick ice. Now, scientists believe that Europa may actually be capable of harboring life since it meets three essential conditions: biochemically useful molecules, a source of energy, and a liquid solvent (water) in which dissolved substances can chemically react with each other.

But to ultimately find life on Europa, we have to get beneath the ice by one day putting a lander on the surface, potentially carrying a submarine.

9. Jupiter has the brightest auroras in the solar system
Artistic impression of an aurora on Jupiter.

From time to time, people are treated to nature’s dazzling fireworks show; the Aurora borealis, also known as the Northern Lights. This eye candy phenomenon is caused by the collision of energetic charged particles with atoms in the high altitude atmosphere — and it’s not reserved to Earth. Auroras have also been spotted on Mars, Uranus, and, yes, Jupiter.

Jupiter actually experiences the most intense auroras in the solar system, being hundreds of times brighter than on Earth. Just like on Earth, auroras on Jupiter are caused by solar storms. However, Jupiter has an additional source for its auroras: charged particles thrown into space by its orbiting moon Io, which is famous for its many large volcanoes.

10. Jupiter is a ‘failed star’

The gas giant is virtually made of 90% hydrogen and 10% helium, that’s mighty close to the sun’s composition. In fact, some consider Jupiter to be a ‘failed star’. Jupiter is already a big boy, but if it were roughly 80 times more massive than it is, it could have collapsed under its own gravity to form a star.

11. Jupiter is the solar system’s asteroid vacuum cleaner

Due to its sheer mass and proximity to the Kuiper belt — a huge region of space beyond Neptune packed with asteroids and dwarf planets — Jupiter attracts a lot of visitors. Astronomers believe Jupiter experiences at least 200 times more meteorite impacts than Earth. So, kudos to Jupiter for clearing the solar system of potentially hazardous asteroids that might have come dangerously close to Earth.


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