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Scientists found mineral never seen before in nature – AKIpress

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Scientists found mineral never seen before in nature

AKIPRESS.COM – Top scientists were stunned after discovering a never-before-seen mineral in the heart of a meteorite.

The so-called Wedderburn meteorite, found near an old Australian gold-rush town with the same name in 1951 had left experts baffled for decades – until now.

Now, a study led by mineralogist Chi Ma found the meteorite contained the first occurrence of “edscottite” a rare iron-carbine mineral that has not been seen in nature before.

Scientists have been able to produce the mineral in the lab using a form of iron smelting.

The black-and-red space rock has been examined by several research teams to the extent that now only a third of the original is left intact.

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'NOVA Universe Revealed' on PBS brings the cosmos down to Earth tonight – Space.com

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PBS’s newest science series, NOVA Universe Revealed, premieres tonight, Oct. 27, at 9 p.m. EDT (0100 GMT Oct. 28).

Space.com got a sneak peek at the five-episode series, which takes viewers on an epic journey through the cosmos. The first hour-long episode focuses on our sun and stars like it. Titled “Age of Stars,” it explores the life and death cycle of a star, including stunning archival footage from the ESA, Hubble Space Telescope and NASA, among other space organizations. Imagery from NASA’s Solar Dynamics Observatory makes for a gorgeous look at our sun. Scientists interviewed in the episode explain how a star is born and how it explodes into a supernova, and speculate about an ultimate age of darkness. 

Future episodes will explore other parts of the universe, including our Milky Way galaxy, the search for extraterrestrial life on other planets, black holes and the Big Bang. All episodes feature photorealistic animations, stunning photos, archival footage from space missions, and commentary from a diverse set of scientists. 

Related: The Universe: From the Big Bang to now in 10 easy steps

When deciding on the five topics NOVA Universe Revealed would tackle, there was only one that NOVA executive producer Chris Schmidt worried about pulling off: the Big Bang. 

“Stars, black holes, alien worlds, and galaxies — those are all objects with edges,” he told Space.com. “How do you do the story of everything?”

In the end, the episode worked beautifully. It opens with images of many of the universe’s most spectacular sights, from pulsars to enormous black holes, and humanity’s mission to explore the universe’s biggest mysteries. From there, the episode looks at the universe in reverse from a human perspective: we backtrack from the beginning of human life on Earth to the beginning of our galaxy, all the way to the beginning of the universe and even speculate about the moments before the Big Bang. 

Related: The strangest black holes in the universe

Related stories:

This episode, as well as the others, works so well because it tells the story of the universe in a way that NOVA’s viewers can connect to. 

“There’s a moment at the end [of the Big Bang episode] where Jim Gates acknowledges the idea that all of the stuff we’re made of is just the matter that was created with the Big Bang,” Schmidt said. “And to that extent, we’re part of the universe.”

Schmidt hopes this poetic idea, that all humans are inherently part of the universe, will enthrall viewers. “It’s a great opportunity to take a moment and look up from your feet,” he said. While we’re all preoccupied with our daily lives, it can be interesting and inspiring to consider the vast universe that exists beyond our sky. 

NOVA Universe Revealed was created in collaboration with BBC Studios Science Unit. New episodes will air every Wednesday at 9 p.m. ET/8CT, with the last episode airing November 24. All five episodes are currently available for free streaming on pbs.org/nova and on the PBS video app.

Follow Kasandra Brabaw on Twitter @KassieBrabaw. Follow us on Twitter @Spacedotcom and on Facebook. 

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New Measurement Rules Out Sterile Neutrinos – Forbes

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The history of science is a tumultuous one, with fascinating discoveries that either validate a theory or consign it to the trash heap of history. A recent measurement of the properties of ghostlike subatomic particles called neutrinos appears to have signed the death warrant of a theory that was thought by many to be a solution to many cosmological mysteries. A hypothetical particle called a sterile neutrino now appears to have been ruled out. Sterile neutrinos are different from ordinary neutrinos, which have been observed. Sterile neutrinos have also been considered to be a candidate for dark matter, although this is only speculation. This measurement was performed at Fermi National Accelerator Laboratory (Fermilab), America’s flagship particle physics facility, located just outside Chicago.

Ordinary neutrinos are the lightest and least interactive of the known subatomic particles. They are created in great quantities in nuclear reactors, and they interact so little that they can pass through the entire Earth with little chance of interacting during their passage. There are three known categories of ordinary neutrinos – the electron type, the muon type, and the tau type.

Ordinary neutrinos are unique in the subatomic world in that they can change their identity as they travel in a process called “neutrino oscillation.” The first hints that this was true was observed when researchers in the 1960s tried to detect neutrinos coming from the biggest nuclear reactor around – the Sun. The Sun emits only electron type neutrinos and physicists can calculate how many of them are emitted and should be detected here on Earth. Measurements of the number of solar neutrinos hitting the detectors of the 1960s and 1970s only found a third as many neutrinos as expected. This was called the “solar neutrino problem.”

The solution to the mystery turned out to be simple. These early detectors could only see the passage of electron type neutrinos. In the journey from the Sun to Earth, some of the electron type neutrinos had morphed into the other two varieties. Since those varieties didn’t interact in the detectors, the predictions and measurements disagreed. Definitive studies proving that this oscillation phenomenon was the answer to the mystery were announced in 1998 and 2001.

While the study of nuclear reactions is one method for investigating the properties of ordinary neutrinos, it isn’t the only method available to researchers. Scientists can also use particle accelerators to make beams of neutrinos that they can then direct towards waiting detectors. When physicists make beams of ordinary neutrinos using this technique, the beams consist essentially entirely of muon type neutrinos.

In the 1990s, scientists at the Los Alamos National Laboratory in New Mexico were using beams of muon type neutrinos to try to understand the solar neutrino problem. While their beam was mostly muon type neutrinos, their detector also flagged the passage of electron type neutrinos. Although the phenomenon of neutrino oscillation had not yet been definitively demonstrated, several earlier measurements suggested how quickly muon type neutrinos should oscillate into the other two varieties. However, the Los Alamos measurements suggested that they were oscillating more quickly than was expected.

One possible solution that was proposed to explain the Los Alamos measurement was that there existed a fourth type of neutrino, which is called a sterile neutrino. If it existed, this type of neutrino was even more insubstantial than the ordinary types of neutrinos. Unlike the ordinary type, sterile neutrinos wouldn’t be emitted by nuclear reactors or particle beams and would only make their presence known by speeding up neutrino oscillations.

In 2002, an experiment at Fermilab was performed to reproduce the Los Alamos measurement. The Fermilab experiment was called MiniBooNE. MiniBooNE also saw more electron type neutrinos than expected and this was considered to be additional evidence that sterile neutrinos were real. However, MiniBooNE had a significant limitation. It couldn’t distinguish between an electron or photon produced when a neutrino interacted in the detector. This meant that the MiniBooNE measurement was not definitive.

To finally determine whether the idea of sterile neutrinos was right or not, a third experiment was proposed, called MicroBooNE. MicroBooNE does not suffer from the limitations of the previous experiments. In a seminar presented on October 27, the MicroBooNE collaboration announced that four different searches for an excess of electron type neutrinos found nothing. It appears that the sterile neutrino is not real.

Failure to find sterile neutrinos is a disappointment to those who championed the idea, and also to those who thought that sterile neutrinos might also be dark matter. However, the history of science is full of ideas that didn’t pan out. 

The MicroBooNE experiment is not yet complete. Today’s announcement was based on only half of their data. In addition, they continue to develop new techniques and methods to comb through the data, looking for anything they might have overlooked. It remains possible that their full analysis might turn up something unexpected. It wouldn’t be the first time that neutrinos surprised scientists.

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Have astronomers found the first planet outside of our galaxy? It's complicated – CNET

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The Whirlpool Galaxy, some 28 million light-years from Earth, looks to our telescopes like a cosmic hurricane littered with sparkling gemstones. Huge, lean arms spiral out from the center of Whirlpool, also known as M51. Cradled within them are young stars flaring to life and old stars expanding, expiring and exploding. 

In 2012, NASA’s Chandra Observatory, which sees the sky in X-rays, spotted a curious flicker coming from the galaxy. An X-ray source in one of Whirlpool’s arms switched off for about two hours before suddenly flaring back to life. This isn’t particularly unusual for X-ray sources in the cosmos. Some flare, others periodically dim. 

This particular source emanated from an “X-ray binary,” known as M51-ULS-1, which is actually two objects: Cosmic dance partners that have been two-stepping around each other for potentially billions of years. One of these objects is either a black hole or a neutron star, and the other may be a large, very bright type of star known as a “blue supergiant.”

As astronomers looked a little more closely at the X-ray signal from the pair, they began to suspect the cause for the dimming may have been something we’ve never seen before: A world outside of the Milky Way, had briefly prevented X-rays from reaching our telescopes. The team dubbed it an “extroplanet.”

A research team led by astronomer Rosanne Di Stefano, of the Harvard-Smithsonian Center for Astrophysics, published details of their hypothesis in the journal Nature Astronomy on Oct. 25. Their study lays out evidence that the X-ray wink detected by Chandra was potentially caused by a planet, about the size of Saturn, passing in front of M51-ULS-1.

The extroplanet candidate goes by the name “M51-1” and is believed to orbit its host binary at about the same distance Uranus orbits our sun.

While many news sources have championed the detection as the “first planet discovered outside of the Milky Way,” there’s no way of confirming the find. At least, not for another few decades, when the proposed planet is supposed to make another transit of the binary. Di Stefano says the team modeled other objects that could potentially produce the dip in X-rays but came up short. Still, she stresses this is not a confirmed detection.

“We cannot claim that this is definitely a planet,” says Di Stefano, “but we do claim that the only model that fits all of the data … is the planet candidate model.”

While other astronomers are excited by the use of X-rays as a way of discovering distant worlds, they aren’t as convinced Di Stefano’s team has been able to rule out other objects such as large, failed stars known as brown dwarfs or smaller, cooler M stars. 

“Either this is a completely unexpected exoplanet discovered almost immediately in a small amount of data, or it’s something quite common or garden variety,” says Benjamin Pope, an astrophysicist studying exoplanets at the University of Queensland in Australia.

Hunting for hidden worlds

Astronomers have been probing the skies for decades, searching for planets outside of our solar system. The first confirmed detection of an exoplanet came in 1992 when two or more bodies were detected around the rapidly spinning neutron star PSR1257+12

Prior to these first detections, humans had mostly imagined planets very similar to those we become familiar with in preschool. Rocky planets like the Earth and Mars, gas giants like Jupiter and smaller worlds, like Pluto, far from the sun. Since 1992, our ideas have proven to be extremely unimaginative. 

Exoplanets are truly alien worlds with extremely strange features. There’s the planet where it rains iron, the mega Jupiter that orbits its home star in an egg-shaped orbit, a “naked” planet in the Neptune desert and a ton of super-Earths that seem to resemble home, just a little engorged. Dozens of strange, new worlds continue to be found by powerful planet-hunting telescopes each year. 

But all of these worlds have, so far, been located within the Milky Way. 

The Whirlpool Galaxy, M51, in X-ray and optical light.


NASA/CXC/SAO/R. DiStefano, et al.

It’s very likely (in fact, it’s practically certain) that planets exist outside of our galaxy — we just haven’t been able to detect them yet. Our closest galactic neighbor, Andromeda, is approximately 2.5 million light-years away. The farthest exoplanet we’ve found resides at just 28,000 light-years from Earth, according to the NASA Exoplanet Catalog

Finding planets outside the solar system is not easy because less and less light makes its way across the universe to our telescopes. Astronomers rarely “see” an exoplanet directly. This is because the bright light from a star in nearby planetary systems usually obscures any planets that might orbit around it. 

To “see” them, astronomers have to block out a star’s rays. Less than 2% of the exoplanets in NASA’s 4,538-strong catalog have been found by this method, known as “direct imaging.” 

But one highly successful method, accounting for over 3,000 exoplanet detections, is known as the “transit” method. Astronomers point their telescopes at stars and then wait for periodic dips in their brightness. If these dips come with a regular cadence, they can represent a planet, moving around the star and, from our view on Earth, periodically eclipsing its fiery host. It’s the same idea as a solar eclipse, when the moon passes directly in front of our sun and darkness descends over the Earth.

It’s this method that was critical to the discovery of M51-1. However, instead of detecting dips in visible light (a form of electromagnetic radiation), the team saw a dip in the X-rays (a different form of electromagnetic radiation). Because those X-rays were emanating from a relatively small region, Di Stefano says, a passing planet seems like it could block most or all of them.

M51-1

If M51-1 is a planet, Di Stefano’s team believe it may have had a tumultuous life. 

It’s gravitationally bound to the X-ray binary M51-ULS-1, which Di Stefano’s team posits consists of a black hole or neutron star orbiting a supergiant star. In the eons-old dance between the pair, the black hole or neutron star has been siphoning off mass from the supergiant. This mass, made of hot dust and gas, is constantly in motion around the black hole/neutron star in what’s known as an accretion disk. This hot disk gives off the X-rays detected by Chandra.

Regions of space around X-ray binaries are violent places, and this disk doesn’t give off X-rays in a stable manner. Sometimes, the X-rays seem to switch off for hours, but pinning down the reason is hard. “Within the very wide range of kinds of behaviors of these dynamic systems, it’s possible that some variation in the accretion rate or something like that could give rise to events like this,” says Duncan Galloway, an astrophysicist at Monash University studying neutron star binaries.

m51-lightcurve

The dip in X-ray brightness is apparent on this graph, just prior to 45 hours — but was it caused by a planet?


NASA/CXC/SAO/R. DiStefano, et al.

One belief is that the dimming could result from some of the hot gas and dust in the system obscuring the signal. Di Stefano says this is not the case, because gas and dust would provide a different signal. “As they pass in front of the X-ray source, some of the light from the source begins to interact with the outer regions of the cloud and this gives a distinctive spectral signature,” she notes.

Another possibility is that the X-ray dimming was caused by different types of stars obscuring our view. One type, known as a brown dwarf, arises when a star fails to properly ignite. Another, an M dwarf, is a common type of star sometimes dubbed a “red dwarf.” But due to the age of the M51-ULS-1 system, Di Stefano’s team believe these objects would be much larger than the object they’ve detected.

Di Stefano’s team ran a load of models exploring various scenarios for why the X-ray source switched off. In the end, she says, it was a Saturn-sized planet that seemed to fit what they were seeing best.

“The planet candidate model was the last one standing, so to speak,” says Di Stefano.

Pope is less convinced. “Personally, I wouldn’t bet that this is a planet,” he says. “In my view this is probably a stellar companion or something exotic happening in the disk.” 

Trust the process

This isn’t the first time NASA’s Chandra observatory has been swept up in a potential “extroplanet” find. Studying how radiation from distant stars is “bent” by gravity, a technique known as microlensing, astronomers at the University of Oklahoma believed they detected thousands of extragalactic planets back in 2018. Earlier studies have claimed to find evidence of extragalactic planets in the Andromeda galaxy.

Other astronomers were skeptical about these detections, too. The same skepticism has played out in the case of M51-1. And, importantly, that’s perfectly normal. 

This is the scientific process in action. Di Stefano’s team have argued their case: M51-1 is an extragalactic planet. Now there’s more work to do. Confirmation that M51-1 is planetary won’t be possible until it makes another transit of the X-ray binary in many decades’ time, but there are other ways for astronomers to vet their results. 

Pope notes that if we found analogous systems in the Milky Way, we’d be able to follow up with optical telescopes and get a better understanding of what might be happening at these types of systems. 

We know there must be planets outside of the Milky Way, and so, eventually, humans will discover them. For Galloway, the study is exciting not because of what caused the X-ray binary to dip in brightness, but what happens next. 

“The really exciting thing is there might be additional events in other data, so now we have a motivation where we can go and look for them,” he says.

Di Stefano feels the same way, hoping the publication will bring others into this type of research. She says the team is working hard, studying the skies for other X-ray binaries that may exhibit similar dimming.

“Ultimately,” she notes, “the best verification will be the discovery of more planets.”

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