A pair of supermassive black holes that will soon become one has been discovered hiding in a nearby galaxy.
The two black holes dance around each other at the center of the galaxy NGC 7727, located some 89 million light-years away from Earth in the constellation Aquarius. Scientists say they have never seen such a pair so close to our planet, but also so close to each other.
The black hole couple, which will merge into one giant black hole 250 million years from now, escaped detection for so long because it somehow doesn't emit much X-ray radiation, the usual giveaway indicating the presence of black holes. It was discovered and analyzed by a power couple of telescopes, the Very Large Telescope at the European Southern Observatory (ESO) in Chile and the Hubble Space Telescope.
"It is the first time we find two supermassive black holes that are this close to each other, less than half the separation of the previous record holder," Karina Voggel, an astronomer at the Strasbourg Observatory in France and lead author of the new study, said in a statement.
The previous record holder for the closest known black hole couple lies 470 million light-years away from Earth, more than five times farther than the newly discovered duo. The close distance of the NGC 7727 pair enabled astronomers for the first time to determine the masses of the two black holes by measuring how their gravity affects stars in their vicinity.
The larger of the two black holes has a mass of almost 154 million suns. The smaller one, which orbits its larger companion at a distance of only 1,600 light-years, is 6.3 million times more massive than our star.
Supermassive black holes usually sit at the center of large galaxies, and when two galaxies collide and merge, so do the black holes.
The discovery, scientists said, provides a glimpse into the formation of very large supermassive black holes, but also suggests that many more black holes and merging pairs might be lurking in other nearby galaxies.
"Our finding implies that there might be many more of these relics of galaxy mergers out there and they may contain many hidden massive black holes that still wait to be found," said Voggel. "It could increase the total number of supermassive black holes known in the local universe by 30%."
This image shows close-up (left) and wide (right) views of the two bright galactic nuclei of NGC 7727 89 million light-years from Earth. Each nuclei is home to a supermassive black hole at its center.(Image credit: ESO/Voggel et al.; ESO/VST ATLAS team. Acknowledgement: Durham University/CASU/WFAU)
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Scientists expect to supercharge the search for supermassive black holes and black hole pairs in the upcoming years with the completion of ESO's Extremely Large Telescope (ELT) in northern Chile, which is currently expected in 2024.
"With the HARMONI [High Angular Resolution Monolithic Optical and Near-infrared Integral field spectrograph] instrument on the ELT we will be able to make detections like this considerably further than currently possible," ESO astronomer Steffen Mieske, a co-author of the discovery, said in the statement.
The discovery was described in a paper published on Nov. 30 in the journal Astronomy & Astrophysics.
Today's quantum computers are complicated to build, difficult to scale up, and require temperatures colder than interstellar space to operate. These challenges have led researchers to explore the possibility of building quantum computers that work using photons—particles of light. Photons can easily carry information from one place to another, and photonic quantum computers can operate at room temperature, so this approach is promising. However, although people have successfully created individual quantum "logic gates" for photons, it's challenging to construct large numbers of gates and connect them in a reliable fashion to perform complex calculations.
Now, Stanford University researchers have proposed a simpler design for photonic quantum computers using readily available components, according to a paper published Nov. 29 in Optica. Their proposed design uses a laser to manipulate a single atom that in turn, can modify the state of the photons via a phenomenon called "quantum teleportation." The atom can be reset and reused for many quantum gates, eliminating the need to build multiple distinct physical gates, vastly reducing the complexity of building a quantum computer.
"Normally, if you wanted to build this type of quantum computer, you'd have to take potentially thousands of quantum emitters, make them all perfectly indistinguishable, and then integrate them into a giant photonic circuit," said Ben Bartlett, a Ph.D. candidate in applied physics and lead author of the paper. "Whereas with this design, we only need a handful of relatively simple components, and the size of the machine doesn't increase with the size of the quantum program you want to run."
This remarkably simple design requires only a few pieces of equipment: A fiber optic cable, a beam splitter, a pair of optical switches and an optical cavity.
Fortunately, these components already exist and are even commercially available. They're also continually being refined since they're currently used in applications other than quantum computing. For example, telecommunications companies have been working to improve fiber optic cables and optical switches for years.
"What we are proposing here is building upon the effort and the investment that people have put in for improving these components," said Shanhui Fan, the Joseph and Hon Mai Goodman Professor of the School of Engineering and senior author on the paper. "They are not new components specifically for quantum computation."
A novel design
The scientists' design consists of two main sections: A storage ring and a scattering unit. The storage ring, which functions similarly to memory in a regular computer, is a fiber optic loop holding multiple photons that travel around the ring. Analogous to bits that store information in a classical computer, in this system, each photon represents a quantum bit, or "qubit." The photon's direction of travel around the storage ring determines the value of the qubit, which like a bit, can be 0 or 1. Additionally, because photons can simultaneously exist in two states at once, an individual photon can flow in both directions at once, which represents a value that is a combination of 0 and 1 at the same time.
The researchers can manipulate a photon by directing it from the storage ring into the scattering unit, where it travels to a cavity containing a single atom. The photon then interacts with the atom, causing the two to become "entangled," a quantum phenomenon whereby two particles can influence one another even across great distances. Then, the photon returns to the storage ring, and a laser alters the state of the atom. Because the atom and the photon are entangled, manipulating the atom also influences the state of its paired photon.
"By measuring the state of the atom, you can teleport operations onto the photons," Bartlett said. "So we only need the one controllable atomic qubit and we can use it as a proxy to indirectly manipulate all of the other photonic qubits."
Because any quantum logic gate can be compiled into a sequence of operations performed on the atom, you can, in principle, run any quantum program of any size using only one controllable atomic qubit. To run a program, the code is translated into a sequence of operations that direct the photons into the scattering unit and manipulate the atomic qubit. Because you can control the way the atom and photons interact, the same device can run many different quantum programs.
"For many photonic quantum computers, the gates are physical structures that photons pass through, so if you want to change the program that's running, it often involves physically reconfiguring the hardware," Bartlett said. "Whereas in this case, you don't need to change the hardware—you just need to give the machine a different set of instructions."
More information: Ben Bartlett et al, Deterministic photonic quantum computation in a synthetic time dimension, Optica (2021). DOI: 10.1364/OPTICA.424258
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Efforts are about to get under way to drill a core of ice in Antarctica that contains a record of Earth's climate stretching back 1.5 million years.
A European team will set up its equipment at one of the highest locations on the White Continent, for an operation likely to take four years.
The project aims to recover a near-3km-long cylinder of frozen material.
Scientists hope this ice can help them explain why Earth's ice ages flipped in frequency in the deep past.
"Beyond EPICA", as the project is known, is a follow-up to a similar venture at the turn of the millennium called simply EPICA (European Project for Ice Coring in Antarctica).
The new endeavour will base itself a short distance away from the original at Little Dome C, an area located roughly 40km from the Italian-French Concordia Station, on the east Antarctic plateau.
At an altitude of 3,233m above sea level and over 1,000km from the coast, Little Dome C will be an inhospitable place to work. Even in summer, temperatures won't get much above -35C.
The camp where the drill team will base itself was set up in the 2019/20. This coming season will largely be about putting in the necessary drilling infrastructure. But the technicians do aim to at least start on their core quest by getting down beyond the first 100m.
This should take the borehole past the lightly compacted snow layers, or firn, into the impervious ice layers that are the real interest for scientists.
The deep ice in Antarctica contains tiny bubbles of air. These little gas pockets are a direct snapshot of the historic atmosphere.
Scientists can read off the levels of carbon dioxide and other heat-trapping components, such as methane.
Analysing the atoms in the water-ice molecules encasing the gases also gives an indication of the temperature that persisted at the time of the snowfall that gave rise to the ice.
When researchers drilled the original EPICA core, they uncovered a narrative of past climate temperature and atmospheric carbon dioxide stretching back 800,000 years.
It's become one of the key climate data-sets of recent decades.
It showed that CO2 and temperature moved in lock-step. Whenever the Earth went into an ice age and temperature fell, the concentration of greenhouse gases in the atmosphere would also decline. And when the climate warmed back up again, the CO2 rose in parallel.
These cycles occurred roughly every 100,000 years - a phasing that is most likely linked to slight shifts in the eccentricity of Earth's orbit (a larger or smaller ellipse) around the Sun.
But it is recognised from an alternative record of past climate, which has been deciphered from ocean sediments, that deeper back in time the ice age cycle was much shorter - at about every 41,000 years.
That is a period probably dominated by the way the Earth tilts back and forth on its axis. But why the switch occurred, no-one is really sure. The new Beyond Epica core may contain some clues if its ices can extend the climate narrative back to 1.5 million years ago.
"We believe this ice core will give us information on the climate of the past and on the greenhouse gases that were in the atmosphere during the Mid-Pleistocene Transition (MPT), which happened between 900,000 and 1.2 million years ago," said team-leader Carlo Barbante, the director of the Institute of Polar Sciences of the National Research Council of Italy.
"During this transition, climate periodicity between ice ages changed from 41,000 to 100,000 years: the reason why this happened is the mystery we hope to solve."
Armand Patoir/PNRA
To achieve an 800,000-year record, the original EPICA project drilled to a depth of 2,774m. The bedrock at Little Dome C is just over 2,800m down. The extra 700,000 years being sought by the new project should be in the additional metres of layered ice.
"We already have the 800,000 years of ice, so much of the first few years of drilling will simply be a repeat of ice we already have," explained Robert Mulvaney from the British Antarctic Survey.
"In practice, with many new PhD students coming online, and new groups getting involved, and new analytical techniques always being developed, we will make good use of the ice younger than 800,000 years.
"We will also use the younger ice to ensure our techniques are working well by the time we get to the deep ice, where we only get one chance to get all the analyses right," he told BBC News.
Beyond EPICA is funded by the European Union. UK scientists are allowed to participate because the money comes from a period when Britain was still a part of the 27-member-state bloc.
Folded like a $9.7 billion piece of metal origami and nestled into the nose of an Ariane 5 rocket, the James Webb Space Telescope (JWST) will, in late December, be sent nearly one million miles from the surface of the Earth. Once it reaches its destination — a region of space with open views, where the sun and Earth's gravity counterbalance each other — the Hubble telescope's bigger, grander successor will spend the next decade answering questions that are as scientific as they are existential.
"How did we get here? What is the universe? And how did it come into being?" said David Hunter, a project manager at the Space Telescope Science Institute. "With something like the JWST, you actually have a tangible way of finding answers."
Over two decades of work — totaling100 million hoursof labor from more than 1,000 scientists, engineers, and technicians — went into the development of this next-generation space telescope. For their efforts, Webb will be able to peer into distant corners of the universe, using infrared detection to penetrate clouds of dust, survey the atmospheres of potentially habitable exoplanets, and look backward in time over 13 billion years, picking up faint light emitted by galaxies formed in the aftermath of the Big Bang.
Yet this sci-fi-seeming agenda wasn't possible when JWST was first imagined.
"At the beginning, [NASA] identified the technologies that would be needed," explained Hunter. "They went through a development program, looking at all of the parts of the observatory that needed to be built. They figured out which ones we couldn't do yet, and how to advance the engineering capability to do that."
The telescope's signature feature — 18 gold-plated hexagonal mirrors, reaching over 21 feet in diameter, resembling a giant honeycomb — also posed one of its greatest engineering challenges. The mirrors had to be lightweight, yet sturdy enough to hold firmly in place, and capable of folding down to fit into the nose of the carrier rocket. Beneath the mirrors sits the sunshield, another marvel, composed of 5 micro-thin layers of a resilient film called Kapton which will unfurl to the size of a tennis court, protecting the observatory from solar heat. In outer space, deploying the telescope will take a total of 29 days, an intensely nerve-racking window in which hundreds of discrete release mechanisms need to fire in perfect succession.
Transporting the telescope to the verdant European Spaceport in French New Guinea was an ordeal in itself. It arrived on October 12th, following a late-night police escortthrough the streets of Los Angeles and a16-day, 5,800-milesea voyage through the Panama Canal on a custom carrier ship. During transit, controversy over the telescope's name boiled over from the pages of academic journals into the public sphere. Articles inThe Washington PostandNPRdetailed a posthumous investigation into the career of James Webb, a former leader at NASA and the telescope's namesake, who stood accused of discriminating against LGBTQ government employees in the 1940s, '50s, and '60s. But a NASA investigation concluded that the name will stay.
"NASA's History Office conducted an exhaustive search through currently accessible archives on James Webb and his career," NASA spokeswoman Karen Fox told the Washington Post in a statement. "They also talked to experts who previously researched the topic extensively… NASA found no evidence at this point that warrants changing the name of the James Webb Space Telescope."
The JWST has already been a source of news, controversy, and anticipation, but the real headlines, said Hunter, will come once it settles into its stable orbit a million miles from Earth.
"The big stories are going to emerge once we get into regular operations," he said. "It's what we've all been building it for — for the discoveries it will make, which will tell us things we didn't know about the universe."
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Graphic of the sun, solar winds and itokawa. Credit: Curtin University
Curtin University researchers have helped unravel the enduring mystery of the origins of the Earth's water, finding the Sun to be a surprising likely source.
A University of Glasgow-led international team of researchers including those from Curtin's Space Science and Technology Center (SSTC) found the solar wind, comprised of charged particles from the Sun largely made of hydrogen ions, created water on the surface of dust grains carried on asteroids that smashed into the Earth during the early days of the Solar System.
SSTC Director, John Curtin Distinguished Professor Phil Bland said the Earth was very water-rich compared to other rocky planets in the Solar System, with oceans covering more than 70 percent of its surface, and scientists had long puzzled over the exact source of it all.
"An existing theory is that water was carried to Earth in the final stages of its formation on C-type asteroids, however previous testing of the isotopic 'fingerprint' of these asteroids found they, on average, didn't match with the water found on Earth meaning there was at least one other unaccounted for source," Professor Bland said.
"Our research suggests the solar wind created water on the surface of tiny dust grains and this isotopically lighter water likely provided the remainder of the Earth's water.
"This new solar wind theory is based on meticulous atom-by-atom analysis of miniscule fragments of an S-type near-Earth asteroid known as Itokawa, samples of which were collected by the Japanese space probe Hayabusa and returned to Earth in 2010.
"Our world-class atom probe tomography system here at Curtin University allowed us to take an incredibly detailed look inside the first 50 nanometres or so of the surface of Itokawa dust grains, which we found contained enough water that, if scaled up, would amount to about 20 liters for every cubic meter of rock."
Curtin graduate Dr. Luke Daly, now of the University of Glasgow, said the research not only gives scientists a remarkable insight into the past source of Earth's water, but could also help future space missions.
"How astronauts would get sufficient water, without carrying supplies, is one of the barriers of future space exploration," Dr. Daly said.
"Our research shows that the same space weathering process which created water on Itokawa likely occurred on other airless planets, meaning astronauts may be able to process fresh supplies of water straight from the dust on a planet's surface, such as the Moon."
The paper, "Solar wind Contributions to the Earth's Oceans," was published in Nature Astronomy.
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(CNN)The US scientists who created the first living robots say the life forms, known as xenobots, can now reproduce -- and in a way not seen in plants and animals.
Formed from the stem cells of the African clawed frog (Xenopus laevis) from which it takes its name, xenobots are less than a millimeter (0.04 inches) wide. The tiny blobs were first unveiled in 2020 after experiments showed that they could move, work together in groups and self-heal.
Now the scientists that developed them at the University of Vermont, Tufts University and Harvard University's Wyss Institute for Biologically Inspired Engineering said they have discovered an entirely new form of biological reproduction different from any animal or plant known to science.
"I was astounded by it," said Michael Levin, a professor of biology and director of the Allen Discovery Center at Tufts University who was co-lead author of the new research.
"Frogs have a way of reproducing that they normally use but when you ... liberate (the cells) from the rest of the embryo and you give them a chance to figure out how to be in a new environment, not only do they figure out a new way to move, but they also figure out apparently a new way to reproduce."
Robot or organism?
Stem cells are unspecialized cells that have the ability to develop into different cell types. To make the xenobots, the researchers scraped living stem cells from frog embryos and left them to incubate. There's no manipulation of genes involved.
"Most people think of robots as made of metals and ceramics but it's not so much what a robot is made from but what it does, which is act on its own on behalf of people," said Josh Bongard, a computer science professor and robotics expert at the University of Vermont and lead author of the study.
"In that way it's a robot but it's also clearly an organism made from genetically unmodified frog cell."
Bongard said they found that the xenobots, which were initially sphere-shaped and made from around 3,000 cells, could replicate. But it happened rarely and only in specific circumstances. The xenobots used "kinetic replication" -- a process that is known to occur at the molecular level but has never been observed before at the scale of whole cells or organisms, Bongard said.
With the help of artificial intelligence, the researchers then tested billions of body shapes to make the xenobots more effective at this type of replication. The supercomputer came up with a C-shape that resembled Pac-Man, the 1980s video game. They found it was able to find tiny stem cells in a petri dish, gather hundreds of them inside its mouth, and a few days later the bundle of cells became new xenobots.
"The AI didn't program these machines in the way we usually think about writing code. It shaped and sculpted and came up with this Pac-Man shape," Bongard said.
"The shape is, in essence, the program. The shape influences how the xenobots behave to amplify this incredibly surprising process."
The xenobots are very early technology -- think of a 1940s computer -- and don't yet have any practical applications. However, this combination of molecular biology and artificial intelligence could potentially be used in a host of tasks in the body and the environment, according to the researchers. This may include things like collecting microplastics in the oceans, inspecting root systems and regenerative medicine.
While the prospect of self-replicating biotechnology could spark concern, the researchers said that the living machines were entirely contained in a lab and easily extinguished, as they are biodegradable and regulated by ethics experts.
The research was partially funded by the Defense Advanced Research Projects Agency, a federal agency that oversees the development of technology for military use.
"There are many things that are possible if we take advantage of this kind of plasticity and ability of cells to solve problems," Bongard said.
The study was published in the peer-reviewed scientific journal PNAS on Monday.
Jessie Yeung in Hong Kong contributed to this report
On November 28, 1994, American astronomer Carolyn S. Shoemaker spotted the enormous space rock at the Palomar Observatory, which was slightly larger than an American football field.
The JPL Center for NEO Studies (CNEOS) classified it as an Earth Impact Risk until 2016 when it was removed from their Sentry List after several observations.
According to NASA astronomers, the impact of the 1994 WR12 on Earth would produce energy equivalent to 77 megatons of TNT, making it 112 times more powerful than the Tsar Bomba, the largest nuclear weapon ever detonated.
But don’t worry, for the time being, we’re safe. 1994 WR12 will pass Earth at a distance of 3.8 million miles on Monday.
However, a huge asteroid will collide with the Earth’s atmosphere sooner or later. Professor Alan Duffy, head of the Space Technology and Industry Institute, has some sound advice for when this happens: “Don’t look at it.”
“I mean, it‘s going to be hard not to – the brightness of the glare from these objects burning up in the atmosphere,” said the Professor. “That‘s actually what caused a lot of the injuries in Chelyabinsk (a meteor strike in Russia in 2013), people not unreasonably looked up at this enormous burning fireball in the sky, whose brightness was essentially that of the Sun by the time it finally erupted, that caused a lot of retina damage – so make sure you’re not looking right at it.”
Structural comparison: crystalline diamond (left) and paracrystalline diamond (right). On the right, units of carbon atoms arranged in a cube shape are marked in turquoise, units of carbon atoms arranged in a hexagonal shape are marked in yellow. Irregular structures are marked in red. Credit: Hu Tang.
A team of researchers from China, Germany and the U.S. has developed a way to create a less fragile diamond. In their paper published in the journal Nature, the group describes their approach to creating a paracrystalline diamond and possible uses for it.
Prior research has shown that diamond is the hardest known material but it is also fragile—despite their hardness, diamonds can be easily cut or even smashed. This is because of their ordered atomic structure. Scientists have tried for years to synthesize diamonds that retain their hardness but are less fragile. The team has now come close to achieving that goal.
Currently, the way to create diamonds is to place a carbon-based material in a vice-like device where it is heated to very high temperatures while it is squeezed very hard. In this new effort, the researchers have used the same approach to create a less ordered type of diamond but have added a new twist—the carbon-based material was a batch of fullerenes, also known as buckyballs (carbon atoms arranged in a hollow spherical shape). They heated the material to between 900 and 1,300 °C at pressures of 27 to 30 gigapascals. Notably, the pressure exerted was much lower than is used to make commercial diamonds. During processing, the spheres were forced to collapse, and they formed into transparent paracrystalline diamonds which could be extracted at room temperature.
Fig. 1: Synthesizing fully sp3-bonded carbon samples at 30 GPa and 1,200–1,600 K for 10 min. Credit: DOI: 10.1038/s41586-021-04122-w
After making their less-ordered diamonds, the researchers looked at them under an electron microscope to learn more about their structure. They also subjected samples to X-ray diffraction and to atomist modeling. In so doing, they found their diamonds were made of disordered sp3-hybridized carbon, just as they expected. The goal of creating a less fragile diamond had been achieved. Unlike the results of another recent effort to synthesize a less fragile diamond, their resulting diamond is not completely amorphous (which would make it a type of glass), theirs is a type of amorphous diamond paracrystal. This means that it has a medium-range order—its atoms are ordered over short distances but not over long ones. Thus, no plane of atoms exist which means that the diamonds cannot be cut like natural diamonds.
Citation: Creating a less fragile diamond using fullerenes (2021, November 28) retrieved 29 November 2021 from https://ift.tt/318ogtp
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On November 28, 1994, American astronomer Carolyn S. Shoemaker spotted the enormous space rock at the Palomar Observatory, which was slightly larger than an American football field.
The JPL Center for NEO Studies (CNEOS) classified it as an Earth Impact Risk until 2016 when it was removed from their Sentry List after several observations.
According to NASA astronomers, the impact of the 1994 WR12 on Earth would produce energy equivalent to 77 megatons of TNT, making it 112 times more powerful than the Tsar Bomba, the largest nuclear weapon ever detonated.
But don’t worry, for the time being, we’re safe. 1994 WR12 will pass Earth at a distance of 3.8 million miles on Monday.
However, a huge asteroid will collide with the Earth’s atmosphere sooner or later. Professor Alan Duffy, head of the Space Technology and Industry Institute, has some sound advice for when this happens: “Don’t look at it.”
“I mean, it‘s going to be hard not to – the brightness of the glare from these objects burning up in the atmosphere,” said the Professor. “That‘s actually what caused a lot of the injuries in Chelyabinsk (a meteor strike in Russia in 2013), people not unreasonably looked up at this enormous burning fireball in the sky, whose brightness was essentially that of the Sun by the time it finally erupted, that caused a lot of retina damage – so make sure you’re not looking right at it.”
This animation depicts a star experiencing spaghettification as it’s sucked in by a supermassive black hole during a ‘tidal disruption event’. Credit: ESO/M. Kornmesser
Watch as eight stars skirt a black hole 1 million times the mass of the Sun in these supercomputer simulations. As they approach, all are stretched and deformed by the black hole’s gravity. Some are completely pulled apart into a long stream of gas, a cataclysmic phenomenon called a tidal disruption event. Others are only partially disrupted, retaining some of their mass and returning to their normal shapes after their horrific encounters.
Watch eight model stars stretch and deform as they approach a virtual black hole 1 million times the mass of the Sun. The black hole rips some stars apart into a stream of gas, a phenomenon called a tidal disruption event. Others manage to withstand their close encounters. These simulations show that destruction and survival depend on the stars’ initial densities. Yellow represents the greatest densities, blue the least dense. Credit: NASA’s Goddard Space Flight Center/Taeho Ryu (MPA)
These simulations, led by Taeho Ryu, a fellow at the Max Planck Institute for Astrophysics in Garching, Germany, are the first to combine the physical effects of Einstein’s general theory of relativity with realistic stellar density models. The virtual stars range from about one-tenth to 10 times the Sun’s mass.
The division between stars that fully disrupt and those that endure isn’t simply related to mass. Instead, survival depends more on the star’s density.
From left to right, this illustration shows four snapshots of a virtual Sun-like star as it approaches a black hole with 1 million times the Sun’s mass. The star stretches, looses some mass, and then begins to regain its shape as it moves away from the black hole. Credit: NASA’s Goddard Space Flight Center/Taeho Ryu (MPA)
Ryu and his team also investigated how other characteristics, such as different black hole masses and stellar close approaches, affect tidal disruption events. The results will help astronomers estimate how often full tidal disruptions occur in the universe and will aid them in building more accurate pictures of these calamitous cosmic occurrences.
Reference: “Tidal Disruptions of Main-sequence Stars. I. Observable Quantities and Their Dependence on Stellar and Black Hole Mass” by Taeho Ryu, Julian Krolik, Tsvi Piran and Scott C. Noble, 25 November 2021, The Astrophysical Journal. DOI: 10.3847/1538-4357/abb3cf
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Just because a spacecraft is sent to study the moon doesn't mean it can't do a little extra skywatching now and then.
NASA's Lunar Reconnaissance Orbiter (LRO) has been circling the moon since 2009. But a new image NASA shared on Monday (Nov. 22) from the spacecraft shows a very different destination: Saturn, complete with the planet's stunning rings.
LRO snapped the image on Oct. 13 using its Lunar Reconnaissance Orbiter Camera (LROC). At the time, the spacecraft was about 56 miles (90 kilometers) above a lunar feature dubbed Lacus Veris, or the Lake of Spring, according to a NASA statement.
The image shows the northern side of Saturn's characteristic rings and more of the planet's northern hemisphere than the southern. The northern hemisphere's summer ended and its autumn began in March.
The ringed world's year lasts for about 29 Earth years, making each season more than seven Earth years long.
NASA's Lunar Reconnaissance Orbiter caught a picture of Saturn and its rings on Oct. 13, 2021. (Image credit: NASA/GSFC/Arizona State University)
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LROC's cameras were designed to study the moon, of course, so NASA had to manipulate the spacecraft carefully to catch such a stunning image of Saturn.
Although a similar image of Jupiter was able to spot some of the behemoth's largest moons, LRO couldn't pull off the same feat at Saturn. That's because Saturn is dimmer than Jupiter, according to NASA — and both are much dimmer than the moon that LROC is tailored to study.
Email Meghan Bartels at mbartels@space.com or follow her on Twitter @meghanbartels. Follow uson Twitter @Spacedotcomand onFacebook.
Never mind 3D-printing organs — eventually, the material could have a life of its own. Phys.orgreports scientists have developed a "living ink" you could use to print equally alive materials usable for creating 3D structures. The team genetically engineered cells for E. Coli and other microbes to create living nanofibers, bundled those fibers and added other materials to produce an ink you could use in a standard 3D printer.
Researchers have tried producing living material before, but it has been difficult to get those substances to fit intended 3D structures. That wasn't an issue here. The scientists created one material that released an anti-cancer drug when induced with chemicals, while another removed the toxin BPA from the environment. The designs can be tailored to other tasks, too.
Any practical uses could still be some ways off. It's not yet clear how you'd mass-produce the ink, for example. However, there's potential beyond the immediate medical and anti-pollution efforts. The creators envisioned buildings that repair themselves, or self-assembling materials for Moon and Mars buildings that could reduce the need for resources from Earth. The ink could even manufacture itself in the right circumstances — you might not need much more than a few basic resources to produce whatever you need.
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Clytia hemisphaerica from the side. Credit: B. Weissbourd
The human brain has 100 billion neurons, making 100 trillion connections. Understanding the precise circuits of brain cells that orchestrate all of our day-to-day behaviors—such as moving our limbs, responding to fear and other emotions, and so on—is an incredibly complex puzzle for neuroscientists. But now, fundamental questions about the neuroscience of behavior may be answered through a new and much simpler model organism: tiny jellyfish.
Caltech researchers have now developed a kind of genetic toolbox tailored for tinkering with Clytia hemisphaerica, a type of jellyfish about 1 centimeter in diameter when fully grown. Using this toolkit, the tiny creatures have been genetically modified so that their neurons individually glow with fluorescent light when activated. Because a jellyfish is transparent, researchers can then watch the glow of the animal's neural activity as it behaves naturally. In other words, the team can read a jellyfish's mind as it feeds, swims, evades predators, and more, in order to understand how the animal's relatively simple brain coordinates its behaviors.
A paper describing the new study appears in the journal Cell on November 24. The research was conducted primarily in the laboratory of David J. Anderson, Seymour Benzer Professor of Biology, Tianqiao and Chrissy Chen Institute for Neuroscience Leadership Chair, Howard Hughes Medical Institute Investigator, and director of the Tianqiao and Chrissy Chen Institute for Neuroscience.
When it comes to model organisms used in laboratories, jellyfish are an extreme outlier. Worms, flies, fish, and mice—some of the most commonly used laboratory model organisms—are all more closely related, genetically speaking, to one another than any are to a jellyfish. In fact, worms are evolutionarily closer to humans than they are to jellyfish.
With a new genetic toolbox, researchers can view jellyfish neurons as they light up in real time. Jellyfish do not have a centralized brain; rather, their brain cells (neurons) are distributed in a diffuse net throughout the body. As shown in this video, this study discovered that there is actually spatial organization to the way that neurons are activated when the animal is coordinating behavior. Credit: B. Weissbourd
"Jellyfish are an important point of comparison because they're so distantly related," says Brady Weissbourd, postdoctoral scholar and first author on the study. "They let us ask questions like, are there principles of neuroscience shared across all nervous systems? Or, what might the first nervous systems have looked like? By exploring nature more broadly, we may also discover useful biological innovations. Importantly, many jellyfish are small and transparent, which makes them exciting platforms for systems neuroscience. That is because there are amazing new tools for imaging and manipulating neural activity using light, and you can put an entire living jellyfish under a microscope and have access to the whole nervous system at once."
Rather than being centralized in one part of the body like our own brains, the jellyfish brain is diffused across the animal's entire body like a net. The various body parts of a jellyfish can operate seemingly autonomously, without centralized control; for example, a jellyfish mouth removed surgically can carry on "eating" even without the rest of the animal's body.
This decentralized body plan seems to be a highly successful evolutionary strategy, as jellyfish have persisted throughout the animal kingdom for hundreds of millions of years. But how does the decentralized jellyfish nervous system coordinate and orchestrate behaviors?
After developing the genetic tools to work with Clytia, the researchers first examined the neural circuits underlying the animal's feeding behaviors. When Clytia snags a brine shrimp in a tentacle, it folds its body in order to bring the tentacle to its mouth and bends its mouth toward the tentacle simultaneously. The team aimed to answer: How does the jellyfish brain, apparently unstructured and radially symmetric, coordinate this directional folding of the jellyfish body?
A jellyfish folds the right side of its body to bring a tiny brine shrimp to its mouth. Credit: B. Weissbourd
By examining the glowing chain reactions occurring in the animals' neurons as they ate, the team determined that a subnetwork of neurons that produces a particular neuropeptide (a molecule produced by neurons) is responsible for the spatially localized inward folding of the body. Additionally, though the network of jellyfish neurons originally seemed diffuse and unstructured, the researchers found a surprising degree of organization that only became visible with their fluorescent system.
"Our experiments revealed that the seemingly diffuse network of neurons that underlies the circular jellyfish umbrella is actually subdivided into patches of active neurons, organized in wedges like slices of a pizza," explains Anderson. "When a jellyfish snags a brine shrimp with a tentacle, the neurons in the 'pizza slice' nearest to that tentacle would first activate, which in turn caused that part of the umbrella to fold inward, bringing the shrimp to the mouth. Importantly, this level of neural organization is completely invisible if you look at the anatomy of a jellyfish, even with a microscope. You have to be able to visualize the active neurons in order to see it—which is what we can do with our new system."
Weissbourd emphasizes that this is only scratching the surface of understanding the full repertoire of jellyfish behaviors. "In future work, we'd like to use this jellyfish as a tractable platform to understand precisely how behavior is generated by whole neural systems," he says. "In the context of food passing, understanding how the tentacles, umbrella, and mouth all coordinate with each other lets us get at more general problems of the function of modularity within nervous systems and how such modules coordinate with each other. The ultimate goal is not only to understand the jellyfish nervous system but to use it as a springboard to understand more complex systems in the future."
The new model system is straightforward for researchers anywhere to use. Jellyfish lineages can be maintained in artificial sea water in a lab environment and shipped to collaborators who are interested in answering questions using the little animals.
The paper is titled "A genetically tractable jellyfish model for systems and evolutionary neuroscience."
In addition to Weissbourd and Anderson, additional co-authors are Tsuyoshi Momose of Sorbonne Université in France, graduate student Aditya Nair, former postdoctoral scholar Ann Kennedy (now an assistant professor at Northwestern University), and former research technician Bridgett Hunt. Funding was provided by the Caltech Center for Evolutionary Science, the Whitman Center of the Marine Biological Laboratory, the Life Sciences Research Foundation, and the Howard Hughes Medical Institute.
More information: Brandon Weissbourd et al, A genetically tractable jellyfish model for systems and evolutionary neuroscience, Cell (2021). DOI: 10.1016/j.cell.2021.10.021
Citation: How to read a jellyfish's mind (2021, November 26) retrieved 28 November 2021 from https://ift.tt/3DRZvzM
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Figure 1. (Top) 13CO integrated intensity map from the SEDIGISM survey in the velocity range −95 to −75 km s−1 showing a wave-like feature. (Bottom) 12CO integrated intensity map from the ThrUMMS survey in the same velocity range as the top panel, smoothed to an angular resolution of 5'. Images are stretched along the y-axis for a better visualization.
A team of researchers from Germany, France and the U.K. has discovered a long thin filament of dense gas connecting two of the Milky Way galaxy's spiral arms. In their paper published in The Astrophysical Journal Letters, the group describes their work studying carbon monoxide gas in the galaxy.
Prior research has shown that other galaxies have features called feathers—long gas filaments with barbs that look from Earth like feathers. But because it is very difficult to study the Milky Way galaxy from an Earth perspective, no such features have been seen, until now.
In their work, the researchers were studying concentrations of carbon monoxide gas in data from the APEX telescope in San Pedro de Atacama, Chile. They noticed concentrations that had not been seen before, and after taking a closer look, discovered that it was part of a large gas formation that extended from near the center of the galaxy outward, connecting two of the arms that give the galaxy its distinctive look.
The researchers named the formation the Gangotri wave—an homage to the massive glacier whose melting gives rise to the Ganges River. In India, the Milky Way galaxy is known as Akasha Ganga. The newly discovered feather spans approximately 5.6764e+16 to 1.22989e+17 kilometers in reaching between the two arms and is approximately 1.6083242e+17 kilometers from the rotational center of the galaxy. They have also estimated its mass to be approximately equal to nine suns. Prior to the new discovery, all of the gas tendrils found in the Milky Way have aligned with the spiral arms.
The researchers found that the Gangotri wave has another unique and interesting feature in that it is not as straight as expected. Instead, it zig-zags back and forth along its length in a pattern similar to a sine wave. The researchers were not able to explain the strange phenomenon but note that some force must be at play—a force that is likely to be the focus of many upcoming research efforts. The team plans to continue their study of gases in the Milky Way, this time actively looking for new feathers.
More information: V. S. Veena et al, A Kiloparsec-scale Molecular Wave in the Inner Galaxy: Feather of the Milky Way?, The Astrophysical Journal Letters (2021). DOI: 10.3847/2041-8213/ac341f
Citation: 'Gangotri wave' connecting two of Milky Way's spiral arms discovered (2021, November 27) retrieved 27 November 2021 from https://ift.tt/3D0y3OW
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
