Astronomers To Peer Into A Black Hole For The First Time With New Event Horizon Telescope.


Ever since first mentioned by Jon Michell in a letter to the Royal Society in 1783, black holes have captured the imagination of scientists, writers, filmmakers and other artists. Perhaps part of the allure is that these enigmatic objects have never actually been “seen”. But this could now be about to change as an international team of astronomers is connecting a number of telescopes on Earth in the hope of making the first ever image of a black hole. The Conversation

Black holes are regions of space inside which the pull of gravity is so strong that nothing – not even light – can escape. Their existence was predicted mathematically by Karl Schwarzchild in 1915, as a solution to equations posed in Albert Einstein’s theory of general relativity.

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We don’t know what the black hole at the centre of the Milky Way will look like.

Astronomers have had circumstantial evidence for many decades that supermassive black holes – a million to a billion times more massive than our sun – lie at the hearts of massive galaxies. That’s because they can see the gravitational pull they have on stars orbiting around the galactic centre. When overfed with material from the surrounding galactic environment, they also eject detectable plumes or jets of plasma to speeds close to that of light. Last year, the LIGO experiment provided even more proof by famously detecting ripples in space-timecaused by two medium-mass black holes that merged millions of years ago.

But while we now know that black holes exist, questions regarding their origin, evolution and influence in the universe remain at the forefront of modern astronomy.

Catching a tiny spot on the sky

On April 5-14 2017, the team behind the Event Horizon Telescope hopes to test the fundamental theories of black-hole physics by attempting to take the first ever image of a black hole’s event horizon (the point at which theory predicts nothing can escape). By connecting a global array of radio telescopes together to form the equivalent of a giant Earth-sized telescope – using a technique known as Very Long Baseline Interferometry and Earth-aperture synthesis – scientists will peer into the heart of our Milky Way galaxy where a black hole that is 4m times more massive than our sun – Sagittarius A* – lurks.

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Sagittarius A*. This image was taken with NASA’s Chandra X-Ray Observatory. Ellipses indicate light echoes.
Astronomers know there is a disk of dust and gas orbiting around the black hole. The path the light from this material takes will be distorted in the gravitational field of the black hole. Its brightness and colour are also expected to be altered in predictable ways. The tell-tale signature astronomers hope to see with the Event Horizon Telescope is a bright crescent shape rather than a disk. And they may even see the shadow of the black hole’s event horizon against the backdrop of this brightly shining swirling material.

The array connects nine stations spanning the globe – some individual telescopes, others collections of telescopes – in Antarctica, Chile, Hawaii, Spain, Mexico and Arizona. The “virtual telescope” has been in development for many years and the technology has been tested. However, these tests initially revealed a limited sensitivity and an angular resolution that was insufficient to probe down to the scales needed to reach the black hole. But the addition of sensitive new arrays of telescopes – including the Atacama Large Millimeter Array in Chile and the South Pole Telescope – will give the network a much-needed boost in power. It’s rather like putting on spectacles and suddenly being able to see both headlights from an oncoming car rather than a single blur of light.

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The Atacama Large Millimeter submillimeter Array ALMA by night under the Magellanic Clouds.

The black hole is a compact source on the sky – its view at optical wavelengths (light that we can see) is completely blocked by large quantities of dust and gas. However, telescopes with sufficient resolution and operating at longer, radio millimetre wavelengths can peer through this cosmic fog.

The resolution of any kind of telescope – the finest detail that can be discerned and measured – is usually quoted as a small angle corresponding to the ratio of an object’s size to its distance. The angular size of the moon as seen from the Earth is about half a degree, or 1800 arc seconds. For any telescope, the bigger its aperture, the smaller the detail that can be resolved.

The resolution of a single radio telescope (typically with an aperture of 100 metres) is roughly about 60 arc seconds. This is comparable to the resolution of the unaided human eye and about a sixtieth of the apparent diameter of the full moon. But by connecting many telescopes, the Event Horizon Telescope will be about to achieve a resolution of 15-20 microarcsecond (0,000015 arcseconds), corresponding to being able to spy a grape at the distance of the moon.

What’s at stake?

Although the practice of connecting many telescopes in this way is well known, particular challenges lie ahead for the Event Horizon Telescope. The data recorded at each station in the network will be shipped to a central processing facility where a supercomputer will carefully combine all the data. Different weather, atmospheric and telescope conditions at each site will require meticulous calibration of the data so that scientists can be sure any features they find in the final images are not artefacts.

If it works, imaging the material inside the black hole region with angular resolutions comparable to that of its event horizon will open a new era of black hole studies and solve a number of big questions: do event horizons even exist? Does Einstein’s theory work in this region of extreme strong gravity or do we need a new theory to describe gravity this close to a black hole? Also, how are black holes fed and how is material ejected?

It may even even be possible to image the black holes at the centre of nearby galaxies, such as the giant elliptical galaxy that lies at the heart of our local cluster of galaxies.

Ultimately, the combination of mathematical theory and deep physical insight, global international scientific collaborations and remarkable, tenacious long-term advances in cutting edge experimental physics and engineering look set to make revealing the nature of spacetime a defining feature of early 21st century science.

Source:http://www.huffingtonpost.co.uk/

Gravitational Wave Kicks Monster Black Hole Out Of Galactic Core


Gravitational Wave Kicks Monster Black Hole Out Of Galactic Core

Gravitational Wave Kicks Monster Black Hole Out Of Galactic Core
Runaway black hole is the most massive ever detected far from its central home
Normally, hefty black holes anchor the centers of galaxies. So researchers were surprised to discover a supermassive black hole speeding through the galactic suburbs. Black holes cannot be observed directly, but they are the energy source at the heart of quasars — intense, compact gushers of radiation that can outshine an entire galaxy. NASA’s Hubble Space Telescope made the discovery by finding a bright quasar located far from the center of the host galaxy.Researchers estimate that it took the equivalent energy of 100 million supernovas exploding simultaneously to jettison the black hole. What could pry this giant monster from its central home? The most plausible explanation for this propulsive energy is that the monster object was given a kick by gravitational waves unleashed by the merger of two black holes as a result of a collision between two galaxies. First predicted by Albert Einstein, gravitational waves are ripples in the fabric of space that are created when two massive objects collide.

Astronomers have uncovered a supermassive black hole that has been propelled out of the center of a distant galaxy by what could be the awesome power of gravitational waves.

Though there have been several other suspected, similarly booted black holes elsewhere, none has been confirmed so far. Astronomers think this object, detected by NASA’s Hubble Space Telescope, is a very strong case. Weighing more than 1 billion suns, the rogue black hole is the most massive black hole ever detected to have been kicked out of its central home.

Researchers estimate that it took the equivalent energy of 100 million supernovas exploding simultaneously to jettison the black hole. The most plausible explanation for this propulsive energy is that the monster object was given a kick by gravitational waves unleashed by the merger of two hefty black holes at the center of the host galaxy.

First predicted by Albert Einstein, gravitational waves are ripples in space that are created when two massive objects collide. The ripples are similar to the concentric circles produced when a hefty rock is thrown into a pond. Last year, the Laser Interferometer Gravitational-Wave Observatory (LIGO) helped astronomers prove that gravitational waves exist by detecting them emanating from the union of two stellar-mass black holes, which are several times more massive than the sun.

Hubble’s observations of the wayward black hole surprised the research team. “When I first saw this, I thought we were seeing something very peculiar,” said team leader Marco Chiaberge of the Space Telescope Science Institute (STScI) and Johns Hopkins University, in Baltimore, Maryland. “When we combined observations from Hubble, the Chandra X-ray Observatory, and the Sloan Digital Sky Survey, it all pointed towards the same scenario. The amount of data we collected, from X-rays to ultraviolet to near-infrared light, is definitely larger than for any of the other candidate rogue black holes.”

Chiaberge’s paper will appear in the March 30 issue of Astronomy & Astrophysics.

Hubble images taken in visible and near-infrared light provided the first clue that the galaxy was unusual. The images revealed a bright quasar, the energetic signature of a black hole, residing far from the galactic core. Black holes cannot be observed directly, but they are the energy source at the heart of quasars – intense, compact gushers of radiation that can outshine an entire galaxy. The quasar, named 3C 186, and its host galaxy reside 8 billion light-years away in a galaxy cluster. The team discovered the galaxy’s peculiar features while conducting a Hubble survey of distant galaxies unleashing powerful blasts of radiation in the throes of galaxy mergers.

“I was anticipating seeing a lot of merging galaxies, and I was expecting to see messy host galaxies around the quasars, but I wasn’t really expecting to see a quasar that was clearly offset from the core of a regularly shaped galaxy,” Chiaberge recalled. “Black holes reside in the center of galaxies, so it’s unusual to see a quasar not in the center.”

The team calculated the black hole’s distance from the core by comparing the distribution of starlight in the host galaxy with that of a normal elliptical galaxy from a computer model. The black hole had traveled more than 35,000 light-years from the center, which is more than the distance between the sun and the center of the Milky Way.

Based on spectroscopic observations taken by Hubble and the Sloan survey, the researchers estimated the black hole’s mass and measured the speed of gas trapped near the behemoth object. Spectroscopy divides light into its component colors, which can be used to measure velocities in space. “To our surprise, we discovered that the gas around the black hole was flying away from the galaxy’s center at 4.7 million miles an hour,” said team member Justin Ely of STScI. This measurement is also a gauge of the black hole’s velocity, because the gas is gravitationally locked to the monster object.

The astronomers calculated that the black hole is moving so fast it would travel from Earth to the moon in three minutes. That’s fast enough for the black hole to escape the galaxy in 20 million years and roam through the universe forever.

The Hubble image revealed an interesting clue that helped explain the black hole’s wayward location. The host galaxy has faint arc-shaped features called tidal tails, produced by a gravitational tug between two colliding galaxies. This evidence suggests a possible union between the 3C 186 system and another galaxy, each with central, massive black holes that may have eventually merged.

Based on this visible evidence, along with theoretical work, the researchers developed a scenario to describe how the behemoth black hole could be expelled from its central home. According to their theory, two galaxies merge, and their black holes settle into the center of the newly formed elliptical galaxy. As the black holes whirl around each other, gravity waves are flung out like water from a lawn sprinkler. The hefty objects move closer to each other over time as they radiate away gravitational energy. If the two black holes do not have the same mass and rotation rate, they emit gravitational waves more strongly along one direction. When the two black holes collide, they stop producing gravitational waves. The newly merged black hole then recoils in the opposite direction of the strongest gravitational waves and shoots off like a rocket.

The researchers are lucky to have caught this unique event because not every black-hole merger produces imbalanced gravitational waves that propel a black hole in the opposite direction. “This asymmetry depends on properties such as the mass and the relative orientation of the back holes’ rotation axes before the merger,” said team member Colin Norman of STScI and Johns Hopkins University. “That’s why these objects are so rare.”

An alternative explanation for the offset quasar, although unlikely, proposes that the bright object does not reside within the galaxy. Instead, the quasar is located behind the galaxy, but the Hubble image gives the illusion that it is at the same distance as the galaxy. If this were the case, the researchers should have detected a galaxy in the background hosting the quasar.

If the researchers’ interpretation is correct, the observations may provide strong evidence that supermassive black holes can actually merge. Astronomers have evidence of black-hole collisions for stellar-mass black holes, but the process regulating supermassive black holes is more complex and not completely understood.

The team hopes to use Hubble again, in combination with the Atacama Large Millimeter/submillimeter Array (ALMA) and other facilities, to more accurately measure the speed of the black hole and its gas disk, which may yield more insight into the nature of this bizarre object.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

Source:http://hubblesite.org

The Coming Amnesia


In a talk delivered in Amsterdam a few years ago, science fiction writer Alastair Reynolds outlined an unnerving future scenario for the universe, something he had also recently used as the premise of a short story (collected here).

As the universe expands over hundreds of billions of years, Reynolds explained, there will be a point, in the very far future, at which all galaxies will be so far apart that they will no longer be visible from one another.

Upon reaching that moment, it will no longer be possible to understand the universe’s history—or perhaps even that it had one—as all evidence of a broader cosmos outside of one’s own galaxy will have forever disappeared. Cosmology itself will be impossible.

In such a radically expanded future universe, Reynolds continued, some of the most basic insights offered by today’s astronomy will be unavailable. After all, he points out, “you can’t measure the redshift of galaxies if you can’t see galaxies. And if you can’t see galaxies, how do you even know that the universe is expanding? How would you ever determine that the universe had had an origin?”

There would be no reason to theorize that other galaxies had ever existed in the first place. The universe, in effect, will have disappeared over its own horizon, into a state of irreversible amnesia.

It was an interesting talk that I had the pleasure to catch in person, and, for those interested, it includes Reynolds’s explanation of how he shaped this idea into a short story.

More to the point, however, Reynolds was originally inspired by an article published in Scientific American back in 2008 called “The End of Cosmology?” by Lawrence M. Krauss and Robert J. Scherrer.

That article’s sub-head suggests what’s at stake: “An accelerating universe,” we read, “wipes out traces of its own origins.”

As Krauss and Scherrer point out in their provocative essay, “We may be living in the only epoch in the history of the universe when scientists can achieve an accurate understanding of the true nature of the universe.”

“What will the scientists of the future see as they peer into the skies 100 billion years from now?” they ask. “Without telescopes, they will see pretty much what we see today: the stars of our galaxy… The big difference will occur when these future scientists build telescopes capable of detecting galaxies outside our own. They won’t see any! The nearby galaxies will have merged with the Milky Way to form one large galaxy, and essentially all the other galaxies will be long gone, having escaped beyond the event horizon.”

This won’t only mean fewer luminous objects to see in space; it will mean that, “as a result, Hubble’s crucial discovery of the expanding universe will become irreproducible.”

The authors go on to explain that even the chemical composition of this future universe will no longer allow for its history to be deduced, including the Big Bang.

“Astronomers and physicists who develop an understanding of nuclear physics,” they write, “will correctly conclude that stars burn nuclear fuel. If they then conclude (incorrectly) that all the helium they observe was produced in earlier generations of stars, they will be able to place an upper limit on the age of the universe. These scientists will thus correctly infer that their galactic universe is not eternal but has a finite age. Yet the origin of the matter they observe will remain shrouded in mystery.”

In other words, essentially no observational tool available to future astronomers will lead to an accurate understanding of the universe’s origins. The authors call this an “apocalypse of knowledge.”

[Image: “The Christianized constellation St. Sylvester (a.k.a. Bootes), from the 1627 edition of Schiller’s Coelum Stellatum Christianum.” 

There are many interesting things here, including the somewhat existentially horrifying possibility that any intelligent creatures alive in that distant era will have no way to know what is happening to them, where things came from, even where they currently are (an empty space? a dream?), or why.

Informed cosmology will, by necessity, be replaced with religious speculation—with myths, poetry, and folklore.

It is worth asking, however briefly and with multiple grains of salt, if something similar has perhaps already occurred in the universe we think we know today—if something has not already disappeared beyond the horizon of cosmic amnesia—making even our most well-structured, observation-based theories obsolete. For example, could even the widely accepted conclusion that there was a Big Bang be just an ironic side-effect of having lost some other form of cosmic evidence that long ago slipped eternally away from view?

Remember that these future astronomers will not know anything is missing. They will merrily forge ahead with their own complicated, internally convincing new theories and tests. It is not out of the question, then, to ask if we might be in a similarly ignorant situation.

In any case, what kinds of future devices and instruments might be invented to measure or explore a cosmic scenario such as this? What explanations and narratives would such devices be trying to prove?

[Image: “Woodcut illustration depicting the 7th day of Creation, from a page of the 1493 Latin edition of Schedel’s Nuremberg Chronicle. Note the Aristotelian cosmological system that was used in the Middle Ages, below, with God and His retinue of angels looking down on His creation from above.” Image (and caption) from Star Maps: History, Artistry, and Cartography

Science writer Sarah Scoles looked at this same dilemma last year for PBS, interviewing astronomer Avi Loeb.

Scoles was able to find a small glimmer of light in this infinite future darkness, however: Loeb believes that there might actually be a way out of this universal amnesia.

“The center of our galaxy keeps ejecting stars at high enough speeds that they can exit the galaxy,” Loeb says. The intense and dynamic gravity near the black hole ejects them into space, where they will glide away forever like radiating rocket ships. The same thing should happen a trillion years from now.

“These stars that leave the galaxy will be carried away by the same cosmic acceleration,” Loeb says. Future astronomers can monitor them as they depart. They will see stars leave, become alone in extragalactic space, and begin rushing faster and faster toward nothingness. It would look like magic. But if those future people dig into that strangeness, they will catch a glimpse of the true nature of the universe.

There might yet be hope for cosmological discovery, in the other words, encoded in the trajectories of these bizarre, fleeing stars.

[Images: (top) “An illustration of the Aristotelian/Ptolemaic cosmological system that was used in the Middle Ages, from the 1579 edition of Piccolomini’s De la Sfera del Mondo.” (bottom) “An illustration (influenced by Peurbach’s Theoricae Planetarum Novae) explaining the retrograde motion of an outer planet in the sky, from the 1647 Leiden edition of Sacrobosco’s De Sphaera.” Images and captions from Star Maps: History, Artistry, and Cartography 

There are at least two reasons why I have been thinking about this today. One was the publication of an article by Dennis Overbye earlier this week about the rate of the universe’s expansion.

“There is a crisis brewing in the cosmos,” Overbye writes, “or perhaps in the community of cosmologists. The universe seems to be expanding too fast, some astronomers say.”

Indeed, the universe might be more “virulent and controversial” than currently believed, he explains, caught-up in the long process of simply tearing itself apart.

One implication of this finding, Overbye adds, “is that the most popular version of dark energy—known as the cosmological constant, invented by Einstein 100 years ago and then rejected as a blunder—might have to be replaced in the cosmological model by a more virulent and controversial form known as phantom energy, which could cause the universe to eventually expand so fast that even atoms would be torn apart in a Big Rip billions of years from now.”

In the process, perhaps the far-future dark ages envisioned by Krauss and Scherrer will thus arrive a billion or two years earlier than expected.

The second thing that made me think of this, however, was a short essay called “Dante in Orbit,” originally published in 1963, that a friend sent to me last night. It is about stars, constellations, and the possibility of determining astronomical time in The Divine Comedy.

In that paper, Frederick A. Stebbins writes that Dante “seems far removed from the space age; yet we find him concerned with problems of astronomy that had no practical importance until man went into orbit. He had occasion to deal with local time, elapsed time, and the International Date Line. His solutions appear to be correct.”

Stebbins goes on to describe “numerous astronomical references in [Dante’s] chief work, The Divine Comedy”—albeit doing so in a way that remains unconvincing. He suggests, for example, that Dante’s descriptions of constellations, sunrises, full moons, and more will allow an astute reader to measure exactly how much time was meant to have passed in his mythic story, and even that Dante himself had somehow been aware of differential, or relativistic, time differences between far-flung locations. (Recall, on the other hand, that Dante’s work has been discussed elsewhere for its possible insights into physics.)

But what’s interesting about this is not whether or not Stebbins was correct in his conclusions. What’s interesting is the very idea that a medieval cosmology might have been soft-wired, so to speak, into Dante’s poetic universe and that the stars and constellations he referred to would have had clear narrative significance for contemporary readers. It was part of their era’s shared understanding of how the world was structured.

Now, though, imagine some new Dante of a hundred billion years from now—some new Divine Comedy published in a trillion years—and how it might come to grips with the universal isolation and darkness of Krauss and Scherrer. What cycles of time might be perceived in the lonely, shining bulk of the Milky Way, a dying glow with no neighbor; what shared folklore about the growing darkness might be communicated to readers who don’t know, who cannot know, how incorrect their model of the cosmos truly is?

Curiosity Just Sent Back Some Mysterious Inconsistencies


  • NASA’s Curiosity rover has been sending some mixed signals about the atmosphere surrounding the Red Planet.
  • The conflicting information is making scientists unsure if the planet was ever home to water. The information makes it difficult to model if Mars had water 3.5 billion years ago.

The study of Mars’ surface and atmosphere has unlocked some ancient secrets. Thanks to the efforts of the Curiosity rover and other missions, scientists are now aware of the fact that water once flowed on Mars and that the planet had a denser atmosphere. They have also been able to deduce what mechanics led to this atmosphere being depleted, which turned it into the cold, desiccated environment we see there today.

At the same time though, it has led to a rather intriguing paradox. Essentially, Mars is believed to have had warm, flowing water on its surface at a time when the Sun was one-third as warm as it is today. This would require that the Martian atmosphere had ample carbon dioxide in order to keep its surface warm enough. But based on the Curiosity rover’s latest findings, this doesn’t appear to be the case.

These findings were part of an analysis of data taken by the Curiosity’s Chemistry and Mineralogy X-ray Diffraction (CheMin) instrument, which has been used to study the mineral content of drill samples in the Gale Crater. The results of this analysis were recently published in Proceedings of the National Academy of Science, where the research team indicated that no traces of carbonates were found in any samples taken from the ancient lake bed.

Simulated view of Gale Crater Lake on Mars, depicting a lake of water partially filling Mars’ Gale Crater. Credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS
Simulated view of Gale Crater Lake on Mars, depicting a lake of water partially filling Mars’ Gale Crater. Credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS
To break it down, evidence collected by Curiosity (and a slew of other rovers, landers and orbiters) has led scientists to conclude that roughly 3.5 billion years ago, Mars surface had lakes and flowing rivers. They have also determined, thanks to the many samples taken by Curiosity since it landed in the Gale Crater in 2011, that this geological feature was once a lake bed that gradually became filled with sedimentary deposits.

However, for Mars to have been warm enough for liquid water to exist, its atmosphere would have had to contain a certain amount of carbon dioxide – providing a sufficient Greenhouse Effect to compensate for the Sun’s diminished warmth. Since rock samples in the Gale Crater act as a geological record for what conditions were like billions of years ago, they would surely contain plenty of carbonate minerals if this were the case.

Carbonates are minerals that result from carbon dioxide combining with positively charged ions (like magnesium and iron) in water. Since these ions have been found to be in good supply in samples of Martian rock, and subsequent analysis has shown that conditions never became acidic to the point that the carbonates would have dissolved, there is no apparent reason why they wouldn’t be showing up.

Along with his team, Thomas Bristow – the principal investigator for the CheMin instrument on Curiosity – calculated what the minimum amount of atmospheric carbon dioxide would need to be, and how this would have been indicated by the levels of carbonate found in Martian rocks today. They then sorted through the years worth of the CheMin instrument’s data to see if there were any indications of these minerals.

Comparison of X-ray diffraction patterns of two different samples analyzed by Curiosity’s Chemistry and Mineralogy (CheMin) instrument. Credit: NASA/JPL-Caltech/Ames
Comparison of X-ray diffraction patterns of two different samples analyzed by Curiosity’s Chemistry and Mineralogy (CheMin) instrument.
But as he explained in a recent NASA press release, the findings simply didn’t measure up:

We’ve been particularly struck with the absence of carbonate minerals in sedimentary rock the rover has examined. It would be really hard to get liquid water even if there were a hundred times more carbon dioxide in the atmosphere than what the mineral evidence in the rock tells us.

In the end, Bristow and his team could not find even trace amounts of carbonates in the rock samples they analyzed. Even if just a few tens of millibars of carbon dioxide had been present in the atmosphere when a lake existed in the Gale Crater, it would have produced enough carbonates for Curiosity’s CheMin to detect. This latest find adds to a paradox that has been plaguing Mars researchers for years.

Basically, researchers have noted that there is a serious discrepancy between what surface features indicate about Mars’ past, and what chemical and geological evidence has to say. Not only is there plenty of evidence that the planet had a denser atmosphere in the past, more than four decades of orbital imaging (and years worth of surface data) have yielded ample geomorphological evidence that Mars once had surface water and an active hydrological cycle.

The Gale Crater – the landing location and trek of the Rover Curiosity – as it is today, imaged by the MRO. Credits: NASA/JPL, illustration, T.Reyes
The Gale Crater – the landing location and trek of the Rover Curiosity – as it is today, imaged by the MRO. Credits: NASA/JPL, illustration, T.Reyes
However, scientists are still struggling to produce models that show how the Martian climate could have maintained the types of conditions necessary for this to have been the case. The only successful model so far has been one in which the atmosphere contained a significant amount of CO2 and hydrogen. Unfortunately, an explanation for how this atmosphere could be created and sustained remains illusive.

In addition, the geological and chemical evidence for such a atmosphere existing billions of years ago has also been in short supply. In the past, surveys by orbiters were unable to find evidence of carbonate minerals on the surface of Mars. It was hoped that surface missions, like Curiosity, would be able to resolve this by taking soil and drill samples where water had been known to exist.

But as Bristow explained, his team’s study has effectively closed the door on this:

It’s been a mystery why there hasn’t been much carbonate seen from orbit. You could get out of the quandary by saying the carbonates may still be there, but we just can’t see them from orbit because they’re covered by dust, or buried, or we’re not looking in the right place. The Curiosity results bring the paradox to a focus. This is the first time we’ve checked for carbonates on the ground in a rock we know formed from sediments deposited under water.

Annotated version of the bedrock site in the Gale Crater where the Curiosity rover has taken drill samples. Credit: NASA/JPL-Caltech/MSSS
Annotated version of the bedrock site in the Gale Crater where the Curiosity rover has taken drill samples. 
There are several possible explanations for this paradox. On the one hand, some scientists have argued that the Gale Crater Lake may not have been an open body of water and was perhaps covered in ice, which was just thin enough to still allow for sediments to get in. The problem with this explanation is that if this were true, there would be discernible indications left behind – which would include deep cracks in the soft sedimentary lakebed rock.

But since these indications have not been found, scientists are left with two lines of evidence that do not match up. As Ashwin Vasavada, Curiosity’s Project Scientist, put it:

Curiosity’s traverse through streambeds, deltas, and hundreds of vertical feet of mud deposited in ancient lakes calls out for a vigorous hydrological system supplying the water and sediment to create the rocks we’re finding. Carbon dioxide, mixed with other gases like hydrogen, has been the leading candidate for the warming influence needed for such a system. This surprising result would seem to take it out of the running.

Luckily, incongruities in science are what allow for new and better theories to be developed. And as the exploration of the Martian surface continues  – which will benefit from the arrival of the ExoMars and the Mars 2020 missions in the coming years – we can expect additional evidence to emerge. Hopefully, it will help point the way towards a resolution for this paradox, and not complicate our theories even more!

Source:futurism.com

We’ll Probably Have to Genetically Augment Our Bodies to Survive Mars


The real cost of a one-way ticket to the Red Planet.

 

When it comes to space travel, there’s no shortage of enthusiasm to get humans to Mars, with Space X’s Elon Musk saying his company could take passengers to the Red Planet by 2025, and NASA being asked by Congress to achieve the mission by 2033.

But while making the trip could be technologically feasible in the next decade or two, are humans really physically and psychologically ready to abandon Earth and begin colonising the Red Planet?

 Nope, not a chance, according to a recent paper by cognitive scientist Konrad Szocik from the University of Information Technology and Management in Poland.

Szocik argues that no amount of year-long Martian simulations on Earth or long-duration stays aboard the International Space Station (ISS) could prepare human astronauts for the challenges that Mars colonisation would provide.

“We cannot simulate the same physical and environmental conditions to reconstruct the Martian environment, I mean such traits like Martian microgravitation or radiation exposure,” Szocik told Elizabeth Howell at Seeker.

“Consequently, we cannot predict [the] physical and biological effects of humans living on Mars.”

In a recent article, Szocik and his co-authors discussed some of the political, cultural, and personal challenges Mars colonists would face, and in a nutshell, the team doesn’t think human beings could cut it on the Red Planet – not without making changes to our bodies to help us more easily adapt to the Martian environment.

“My idea is that [the] human body and mind is adapted to live in the terrestrial environment,” Szocik told Rae Paoletta at Gizmodo.

 “Consequently, some particular physiological and psychological challenges during [the] journey and then during living on Mars probably will be too difficult for human beings to survive.”

While NASA astronaut Scott Kelly and Russian cosmonaut Mikhail Kornienko famously spent a year on the ISS – the ordeal was not without significant physiological effects and pains resulting from so much time living in space.

But those hardships would be much less than what travellers to Mars would experience, who would be making much longer journeys – and not knowing when or if they could ever return to Earth.

“These first astronauts will be aware that after the almost one-year journey, they will have to live on Mars for at least several years or probably their entire lives due to the fact that their return will most likely be technologically impossible,” the authors explain.

“Perhaps these first colonisers will know that their mission is a ‘one way ticket’.”

The researchers acknowledge that inducing travellers into a coma-like state might make the voyage itself more bearable, but once they’ve arrived, colonists will be faced with an environment where artificial life support is a constant requirement – that is, until some far-off, future terraforming technology can make Mars’ arid and freezing environment hospitable.

Until that happens, the researchers think that humanity’s best prospects for living on Mars would involve some kind of body or genetic altering that might give us a fighting chance of survival on a planet we’ve never had to evolve on.

“We claim that human beings are not evolutionally adapted to colonise cosmic environments,” the authors explain.

“We suggest that the best solution could be the artificial acceleration of the biological evolution of the astronauts before they start their space deep mission.”

While the team doesn’t provide details of what that would entail in their paper, Szocik told Gizmodo that “permanent solutions like genetical and/or surgical modifications” could make colonists capable of surviving on Mars in ways that unaltered humans can’t.

According to NASA’s former chief scientist for human research, Mark J. Shelhamer, while these ideas may be interesting and help further the discussion about what it will take for humans to adapt to Mars’ environment, once talk turns to genetics, you run into a minefield of other potential issues.

“Already, people have suggested selecting astronauts for genetic predisposition for such things as radiation resistance,” says Shelhamer.

“Of course, this idea is fraught with problems. For one, it’s illegal to make employment decisions based on genetic information. For another, there are usually unintended consequences when making manipulations like this, and who knows what might get worse if we pick and choose what we think needs to be made better.”

Those sound like pretty fair points – especially considering Szocik goes as far as to suggest that “human cloning or other similar methods” might ultimately be necessary to sustain colony populations over generations without running the risk of in-breeding between too few colonists.

Clearly, there’s a lot to work out here, and while some of the researchers’ ideas are definitely a bit out there, we’re going to need to think outside the box if we want to inhabit a planet that at its closest is about 56 million km (33.9 million miles) away.

For his part, Shelhamer is confident that the right kind of training will equip human travellers for the ordeals of their Mars journey – and if current estimateson when we can expect to see this happen are correct, we won’t have too long to wait to see if he’s right.

“I think we can give astronauts the tools – physical, mental, operational – so that they are, individually and as a group, resilient in the face of the unknown,” he told Gizmodo.

“What kind of person thrives in an extreme environment? What types of mission structures are in place to help that person? This needs to be examined systematically.”

Source:sciencealert.com

This Gigantic Ring of Galaxies Could Bring Einstein’s Gravity Into Question


Moving way too fast for current physics to explain.

 

Scientists have discovered that a gigantic ring of galaxies stretching 10 million light-years wide is speeding away from our own galaxy so fast, our current physics models can’t explain it.

Describing the structure as expanding rapidly like a “mini Big Bang”, the team thinks it was formed by a near-miss between the Milky Way and our neighbouring galaxy, Andromeda, which created a ‘sling-shot’ of several smaller galaxies. The only problem is the result is at odds with the conditions predicted by Einstein’s theory of relativity.

 “If Einstein’s gravity were correct, our galaxy would never come close enough to Andromeda to scatter anything that fast,” says one of the team, Hongsheng Zhao from the University of St Andrews in Scotland.

Zhao and his team have been investigating the movements of a ring of small galaxies in the Local Group region of the Universe – a group of at least 54 galaxies, which has its two largest galaxies, the Milky Way and the Andromeda Galaxy, roughly at its centre.

The Milky Way is currently about 2.5 million light-years away from Andromeda, but our neighbouring galaxy is careening towards us at speeds of roughly 402,336 km/h (250,000 mph).

Based on Einstein’s theory of relativity, astronomers estimate that 3.75 billion years from now, the Milky Way and Andromeda will collide, and in the billions of years that follow, the two will be ripped apart to form a brand new galaxy.

But have these two galaxies already experienced a near-miss?

Back in 2013, Zhao and his colleagues suggested that 7 to 11 billion years ago, the Milky Way and the Andromeda Galaxy came scarily close to each other, resulting a “tsunami-like wake” in space that would have flung smaller galaxies out into their current positions.

 You can see a more recent example of this in the image at the top of the page, showing a near-miss of two spiral galaxies, NGC 5426 and NGC 5427.

Having investigated this hypothesis further, the team now says the current velocities of these galaxies agree with this scenario – they appear to be speeding away from us so fast, our current physics models can’t explain it.

“The high galactocentric radial velocities (GRVs) of some Local Group galaxies must have been caused by forces acting on them that our model does not account for,” they conclude in their paper.

Not only that, but these galaxies exist on the exact same plane of the Universe as the Milky Way and the Andromeda Galaxy, which is unlikely to be a coincidence, they argue.

“The ring-like distribution is very peculiar. These small galaxies are like a string of raindrops flung out from a spinning umbrella,” says one of the researchers, Indranil Banik.

“I found there is barely a 1 in 640 chance for randomly distributed galaxies to line up in the observed way. I traced their origin to a dynamical event when the Universe was only half its present age.”

The problem with this scenario is that not only does Einstein’s theory of relativity fail to explain the velocities of these galaxies, it also states that this near-miss should have resulted in the merge of the Milky Way and the Andromeda Galaxy billions of years ago – which obviously never happened.

The reason our current models of gravity require this to have happened is because of one of the most controversial parts of Einstein’s theory – dark matter.

Einstein’s theory of relativity is about as robust as theories get in terms of predicting the behaviour of our Universe, but several major gravitational effects cannot be explained unless we shoehorn this strange and frustratingly elusiveform of matter into the mix.

Thought to make up more than 80 percent of the mass of the entire Universe, dark matter has yet to be directly observed, and it’s not for a lack of effort – a recent US$10 million experiment to find traces of dark matter particles failed to find anything after an exhaustive 20-month search.

But the way that light bends as it travels through the cosmos, and the peculiar way galaxies rotate, cannot be explained without the influence of dark matter in the Universe.

According to Zhao and his team, we could be looking at two possibilities here – either Einstein’s theory of relativity is fine, and there’s some other explanation for why this galaxy ring is speeding so fast (and why we haven’t been able to detect dark matter), or our current model of gravity needs to be revised.

“Several aspects of the spatial distribution of these galaxies would be expected to occur if there was a past close MW-M31 flyby,” the team concludes in a second study released on their latest findings.

“Such an event only makes sense in the context of certain modified gravity theories, where galaxies lack massive dark matter halos and their associated dynamical friction in close encounters, which would otherwise cause a merger.”

The hypothesis recalls another recent paper that argued our current understanding of gravity is wrong.

Last year, physicist Erik Verlinde from the University of Amsterdam suggested that gravity isn’t a fundamental force of nature at all, but is instead an ’emergent phenomenon’ of something we’ve yet to define – just as temperature is an emergent phenomenon of the movement of particles.

As Fiona MacDonald reported for us at the time, Verlinde argues that if we only proposed dark matter to make up for an inconsistency with gravity, then maybe the issue isn’t dark matter at all – maybe the problem is that we don’t really understand how gravity works.

To be clear, both Zhao’s team and Verlinde’s conclusions are just hypotheses right now, and we have a long way to go before we start tearing apart the foundations of modern physics.

But no one can deny that there are some serious holes in our current understanding of the Universe, not least of which is the fact that gravity and other aspects of general relativity don’t gel with quantum mechanics, which has led researchers to seek out a new ‘theory of everything’ that bridges the gap between the two.

When they were investigating the hypothesised ‘near-miss’ of Andromeda and the Milky Way back in 2013, Zhao and his team found that a different model of gravitational behaviour – known as Milgrom’s Modified Newtonian Dynamics(MOND) – explained the movements of nearby galaxies better than the standard model of physics did.

We’ll have to wait and see where all this leads, but it’s pretty cool to think that we’re likely to see some big things happen in theoretical physics in the decades to come – whether Einstein was right or not.

Source:.sciencealert.com

Scientists Say This Rogue Planet Contradicts Existing Models of Planetary Formation


This world is not like the others.

 

A giant rogue world once described as the “planet that shouldn’t be there” looks like it actually formed out in deep space, far from its host star and the cosmic material that usually births planets, according to new research.

The anomaly, called HD 106906b, is a young planet located approximately 300 light-years from Earth in the Crux constellation. HD 106906 was discovered in 2013, and what makes so unique is how distantly it orbits its star – at 650 astronomical units (au), or 650 times the distance from Earth to the Sun.

 That epic stretch gives HD 106906b the record for the largest orbit around a single, Sun-like star, which takes the planet about 1,500 years to complete one loop.

The most puzzling thing about HD 106906b’s aloofness is that its distant orbit places it well beyond the disk of cosmic debris surrounding HD 106906 – the dust and gas from which planets usually form.

429384629834-hd-1HD 106906 and its debris disk bottom-left, with HD 106906b top right. Credit: ESO and A.M. Lagrange/Université Grenoble Alpes

In this case, the debris disk is about 10 times closer to the star than HD 106906b is, begging the question of just where did this bizarre rogue planet come from?

“Our current planet formation theories do not account for a planet beyond its debris disk,” says astrophysicist Smadar Naoz from the University of California, Los Angeles.

Naoz and her team have now developed a model that can track HD 106906b’s orbital path.

 Since HD 106906b was first discovered, scientists have been trying to explain how the planet could have ended up so far removed from HD 106906, since the vast majority of exoplanets are thought to be located inside debris disks.

And the same holds true closer to home in our own Solar System, with all of the planets orbiting the Sun falling inside the Kuiper belt – the circumstellar disk that extends beyond Neptune, encompassing dwarf planets and several other smaller remnants left over from the formation of our Solar System.

Previous research had suggested that HD 106906b might have formed inside the debris disk before gravitational interactions ejected the planet into its far-off exile – but Naoz’s team don’t think that’s the case.

One of the researchers – Erika Nesvold from the Carnegie Institution for Science – created a computer model called Superparticle-Method Algorithm for Collisions in Kuiper belts and debris disks (SMACK), which suggests that the planet formed outside the debris disk.

SMACK took the known data about the HD 106906 system and calculated how an outside planet like HD 106906b would affect the structure of the star’s debris disk.

It’s not known if the HD 106906 system contains any other planets, but the model suggests that the shape of the elliptical debris disk as it currently exists is compatible with the lone orbit of HD 106906b.

“We were able to create the known shape of HD 106906’s debris disk without adding another planet into the system, as some had suggested was necessary to achieve the observed architecture.” Nesvold says.

The model also indicates that HD 106906b most likely formed outside of the disk – if it initially formed inside and then later moved outward, gravitational effects would mean that the disk would hold a different shape to the one it has now.

While this means we still can’t exactly explain how HD 106906b took shape so far from the dust and gas that gives birth to most planets, at least we’ve narrowed down the planet’s origin story a little.

And if we can find more rogue outliers like HD 106906b, the SMACK model could help us learn more about how these planets could be possible.

“Other debris disks that are shaped by the influence of distant giant planets are probably likely,” Nesvold says.

“My modelling tool can help recreate and visualise how the various features of these disks came to be and improve our understanding of planetary system evolution overall.”

Source:http://www.sciencealert.com

Prominent Astrophysicist Calls the Big Bang A “Mirage”


Article Image
Artist conceptualization of the Big Bang.

Science classes the world over teach that the Big Bang is the beginning of our universe, as if it’s established fact. In reality, it’s a theory and one that’s been challenged periodically. In the last few years, two teams of scientists have revived the debate, and offer fascinating alternative models. A recent paper published in the journal Nature, even goes so far as to suggest that the Big Bang was a “mirage.”

This paper was written by astrophysicist Niayesh Afshordi and colleagues, at the University of Waterloo in Ontario, Canada. They built upon the work of physicist Gia Dvali at the Ludwig Maximillian’s University in Munich, Germany. Physicists have some evidence that the Big Bang took place.

For instance, microwave radiation lurking in the background suggests an apocryphal explosion some 13.7 billion years ago, when the Big Bang is said to have taken place. The fact that the universe is still expanding also suggests that all things came from a common point, strengthening the accepted theory. But what happened before it took place has always been a mystery.

Today, we’re told is that everything began with an unimaginably hot, infinitely dense point in space, which did not adhere to the standard laws of physics. This is known as the singularity. But almost nothing is known about it. Afshordi points out in an interview in Nature, “For all physicists know, dragons could have come flying out of the singularity.” Mathematically, the Big Bang itself holds up. But equations can only show us what happened after, not before.

Background radiation in the universe. 

Since the singularity doesn’t fit into normal, predictable physics models and can’t offer a glimpse into its own origins, some scientists are searching for other answers. Dr. Ahmed Farag Ali of Benha University, in Egypt, calls the singularity, “the most serious problem of general relativity.”

He collaborated with Professor Saurya Das of the University of Lethbridge, in Canada, to investigate. In 2015, they released a series of equations which describe the universe, not as an object with a beginning and an end, but as a constantly flowing river, devoid of all boundaries.

There was no Big Bang in this view and similarly no “Big Crunch,” or a time when the universe might stop expanding and begin condensing. They published their work in the journal Physics Letters B, and plan to introduce a follow-up study. The paper attempts a Herculean feat, to heal the rift between general relativity and quantum mechanics.

In this view, the universe began when it filled with gravitons as a bath fills with water. These don’t contain any mass themselves but pass gravity on to other particles. From there, this “quantum fluid” spread out and the speed of expansion accelerated.

So far, it remains a hypothesis which must undergo a battery of tests, before it can compete with or supersede the present model. This isn’t the only challenge to currently accepted theory.

Currently accepted model. NASA Jet Propulsion Laboratory. Caltech.

To get a better idea on how the universe began, Prof. Afshordi and his team created a 3D model it, floating inside a 4D model of “bulk space.” Remember, the fourth dimension is space-time. This 3D model resembled a membrane, so scientists named it the “brane.” Next, they examined stars within the model and realized that over time, some would die off in violent supernova, turning into 4D black holes.

Black holes have an edge called the event horizon. Reach it and nothing will save you from being pulled in. Nothing escapes its omnipotent pull, not light, not even stars. We think of an event horizon as a corona around a black hole, as it is usually represented in 2D images. Everything in space is 3D (4D actually). So it isn’t a ring, but an outer layer of the black hole’s surface.

Afshordi ran the model to see what would happen when a 4D black hole swallowed a 4D star. A 3D brane fired out, as a result. What’s more, the ejected material began expanding in space. So the universe may be the result of a violent interaction between a star and a black hole.

Ashfordi said, “Astronomers measured that expansion and extrapolated back that the Universe must have begun with a Big Bang — but that is just a mirage.”

To learn more about one alternate theory to the Big Bang, click here:

 

Enigmatic Deep Space Flashes Could Be Powering Alien Spaceships, Say Harvard Scientists


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Two Harvard astronomers published a paper with an imagination-grabbing explanation of Fast Radio Bursts (FRBs), mysterious space signals that were first observed in 2007. These bursts are likely to be coming from galaxies billions of lights years away and have enormous energy to be visible from such a distance.

The powerful bursts are millisecond-long and while only 18 of them have been recorded so far, scientists think there could be an estimated 10,000 FRBs speeding through the cosmos every day. Previous theories proposed their sources to be newborn neutron stars or even nebulas powered by pulsar winds. But no concrete originator of the radio waves has yet been identified. This led astronomers at the Harvard-Smithsonian Center for Astrophysics to theorize that the signals could potentially be coming a device that someone created. 

“Fast radio bursts are exceedingly bright given their short duration and origin at great distances, and we haven’t identified a possible natural source with any confidence,” said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics. “An artificial origin is worth contemplating and checking.”

And who would make an “artificial” device in distant space? Yes, it’s aliens.

“We examine the possibility that FRBs originate from the activity of extragalactic civilizations,” said the scientists.

Check out this video from Space.com for some visuals of the idea:

What are some of the clues that point to an unnatural creation for these signals? For one, they are way too hot and bright. According to George Dvorsky at Gizmodo, who interviewed the theorists, the beams have a brightness temperature of 1037 degrees. The number speaks to the amount of microwave radiation of a space object.

Other reasons to suspect aliens – the radio bursts repeat but in a rather unpredictable way and are concentrated around a specific frequency. Both of these factors are not consistent with the neutron star/pulsar explanation of FRBs.

What the Loeb and his co-author Manasvi Lingam suggest may be happening is quite ingenious. They think the bursts could actually be energy beams that are emanating from giant transmitters. Their purpose? To transport spaceships made by advanced alien civilizations at amazing speeds. Imagine solar space vehicles equipped by light sails that absorb the transmitted radio bursts and zip forward through the cosmos. 

The scientists went as far as figuring out the feasibility of creating such a device and while the technology necessary is not something humans can yet muster, more sophisticated spacefaring beings could make it happen. The transmitter would have to be a solar-powered and water-cooled contraption twice the size of Earth, concluded the astronomers. We are talking 15,000 miles in length. The power this would generate could propel payloads of a million tons, which their statement compares to “20 times the largest cruise ships on Earth.”

“That’s big enough to carry living passengers across interstellar or even intergalactic distances,” said Lingam.

To an observer on Earth, the transmission of the radio burst would appear as a brief flash due to relativity. The spacecraft would receive the burst of energy through mirrors that gather the sunlight. The resulting acceleration of the ship could approach the speed of light.

While Loeb readily offers that their work is speculative, he does think there is merit in such thinking.

“Science isn’t a matter of belief, it’s a matter of evidence. Deciding what’s likely ahead of time limits the possibilities. It’s worth putting ideas out there and letting the data be the judge,” explained Loeb.

The scientists also suggested that a way to study the idea further would be to focus on repeated FRBs whose origins cannot be attributed to “cataclysmic astrophysical events”.

You can read their proposal, published in Astrophysical Journal Letters, here.

As far as light sail technology, NASA is planning to test what it calls a Near Earth Asteroid Scout, a sunlight-powered spacecraft, in 2018.

Astronomers aren’t sure if TRAPPIST-1’s planets are habitable after all.


But there’s still some hope!

In what is becoming a bit of a rollercoaster of emotions, it seems that at least a couple – if not all – of the seven planets in the TRAPPIST-1 solar system could have already been stripped of their atmosphere by the star’s radiation, making it unlikely that liquid water could flow on their surfaces after all.

But hold onto your tears; researchers studying TRAPPIST-1’s spectral emissions have found evidence that the star might just be young enough to not have had time to blow away their atmospheres quite yet, meaning we can still dream of life on those far distant worlds a little longer.

 Astronomers from the University of Geneva Observatory in Switzerland have compared the two types of radiation being emitted from the ultra-cool dwarf star TRAPPIST-1, and concluded the star doesn’t seem to be “extremely old”,

That brings into question just how much atmosphere still clings to the surfaces of the star’s beloved family of rocky planets.

For those of you who missed the fuss, TRAPPIST-1 is a star about 39 light-years away that was discovered to have at least three planets last year. At the time, that didn’t seem so remarkable, but then last month, NASA made a much-hyped announcement that TRAPPIST-1 actually hosted a seven-planet system

Nicknamed our sister star system, it’s believed to consist of a large family of seven small, terrestrial bodies occupying tight orbits relatively close to their star.

Last month, astronomers announced that those planets actually consisted of a large family of seven small, terrestrial bodies occupying tight orbits relatively close to the star.

Early speculation suggested that at least a few of the planets could sit within a ‘Goldilocks zone‘, where liquid water might pool on their rocky surfaces, and life could therefore have hypothetically evolved in its tepid oceans.

 The exciting news inspired NASA to release fan art and travel posters displaying planets that appeared larger than our Moon in classic sci-fi styles, all to set our imaginations blazing.

Of course, we should have prepared for broken hearts. The signs were all there.

Orbiting so close to their parent, the planets are more than likely tidally locked, meaning one hemisphere constantly faces their sun while the other side is in perpetual darkness.

Only last month, we were somewhat dismayed to learn that the nearest known planet outside our own Solar System, orbiting Proxima Centauri, is probably just a hunk of bare rock polished of any atmosphere by bursts of radiation from its red dwarf star.

In these cases, radiation from the star ionises gases in the planet’s atmosphere, allowing the particles to be pushed up and away from the planet’s surface on streams of solar wind.

Last year, astronomers considered whether TRAPPIST-1 was another rather temperamental parent, calculating that the inner planets might have lost as much as 15 Earth-oceans of water to this solar scouring effect over the course of their lifetime.

Of course, it would depend on what “lifetime” meant.

In this most recent research, astronomers compared two types of radiation emitted from the dwarf star: X-rays shed by the star’s wispy corona, and ultra-violet light called Lyman-alpha radiation, which comes from the hydrogen atoms from the chromosphere layer just beneath the corona.

It seems TRAPPIST-1 emits less than half as much Lyman-alpha radiation as Proxima Centauri, which is to be expected, since it’s a cooler star.

But the two stars emit about the same amount of X-rays, which, all things considered, is kind of odd, since the X-ray and ultra-violet radiation output for this category of star both decrease over time, with the X-rays fading a lot faster.

“The fact that TRAPPIST-1 emits nearly three times less flux at Lyman-alpha than in the X-ray would thus suggest it is still relatively young,” the researchers write in their paper.

With a fair bit of hand-waving, it seems that “relatively young” could mean anything up from about half a billion years old.

The fact that it spins quite quickly also adds weight to the conclusion that it’s not an extremely old star.

Yet it also means the X-ray emissions were stronger in the past, since they have decreased over time.

Since it’s predicted that the blasts of radiation would blow away any Earth-like atmosphere from the inner two planets within 1 to 3 billion years, and could take between 5 and 22 billion years to strip the rest of the family, there could still yet be liquid water up on those rocks if TRAPPIST-1 is indeed little older than 500 million years old.

There’s further hope in the fact that the spacing of the planets indicates the possibility they migrated in close to their sun from further out in the solar system, subjecting them to intense blasts of radiation for even less time.

“If they migrated within a disk, typical time scales are about 100 million years, but that may not be valid for a system like TRAPPIST-1,” researcher Vincent Bourrier told Camille M. Carlisle at Sky and Telescope. “Uncharted territory here!”

TRAPPIST-1 is a bit of an odd duck, however; in spite of seeming young, its motion through space places it within an older crowd of stars, which is either coincidence or a sign that there is more to learn.

If you still feel any love for our distant dwarf star, NASA just released footage of changes in its brightness taken over an hour period on 22 February, providing a snapshot of one of its planets passing in front the star and dimming its light.

TRAPPIST-1 animation

While a block of blinking pixels might not seem all that exciting, keep in mind this animated image covers just 44 square arcseconds of the sky, which is about the same area as a grain of sand held at arm’s length.

So hold back from ripping down that fabulous TRAPPIST-1e poster … for now. The Brady Bunch of stars is weird enough that it might still have a few secrets up its sleeve.

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