Astronomers Pinpointed the Location of Multiple Weird Radio Bursts Beyond Our Galaxy


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Astronomers Pinpointed the Location of Multiple Weird Radio Bursts Beyond Our Galaxy

Wednesday 4:35pm

Artist’s impressing of the dishes of the Very Large Array localizing a fast radio burst in space for the first time. Image: Danielle Futselaar

Fast radio bursts, powerful pulses of radio energy of unknown cosmic origin, are a source of endless fascination to astronomers and alien conspiracy theory fodder to everybody else. But while most FRBs discovered to date are one-off events—a single chirp in the interstellar void, if you will—these phenomena got more interesting last year when astronomers discovered the very first FRB signal that repeats. Now, they’ve pinpointed its location.

FRB 121102, the only repeating fast radio burst know to science, is located over three billion light years away, in a dwarf galaxy a thousand times dimmer than the Milky Way, according to new research published today in Nature. Not only does the new analysis confirm that mysterious radio bursts emanate from a source far beyond our galaxy, zeroing in on their location means we can start unraveling what exactly that source is.

All we know at this point is that FRBs are coming from something powerful. “These radio flashes must have enormous amounts of energy to be visible from over 3 billion light-years away,” Cornell astronomer and lead study author Shami Chatterjee said in a statement.

“I think this is a really big deal, and I’m really excited about the result,” Peter Williams, an astronomer at Harvard’s Center for Astrophysics who was not involved with the study, told Gizmodo.

Over the past decade, astronomers have cataloged more than a dozen FRBs, seemingly random flashes of radio energy that appear in the sky at farflung locations and then disappear. FRB 121102 was first spotted in 2012 at the Arecibo Observatory in Puerto Rico, one of the world’s most powerful radio telescopes. But unlike earlier FRBs, 1211102 wasn’t just a flash in the pan: follow-up observations in 2015 revealed ten additional radio bursts emanating from the same region of space. “This unambiguously identifies FRB 121102 as repeating,” astronomers wrote of the discovery last year in Nature.

FRB 1211102’s repetitive signal removed any doubt that astronomers are looking at a genuine astrophysical phenomena, rather than, say, random bursts of energy from the nearest microwave oven. Equally important, FRB 121102 proved that whatever is producing fast radio bursts—or at least, some of them—isn’t being destroyed in the process.

Still, much more information was needed to figure out what’s causing FRBs, starting with where in the universe they are coming from. Now, that mystery seems to have been solved for FRB 121102.

Prior to the new study, the patch of sky associated with FRB 121102’s powerful outbursts was several arc minutes in diameter; wide enough to encompass hundreds of potential sources and many galaxies. To more precisely zero in on its location, Chatterjee and his co-authors turned to the National Radio Astronomy Observatory’s Very Large Array (VLA). In 83 hours of observing time last year, they watched FBR 121102 fire off nine additional times, all at a consistent sky position. Follow-up observations with the Gemini North telescope in Hawaii revealed a very faint dwarf galaxy at precisely the location of the source.

A composite image of FRB 121102, located in a dim and distant host galaxy. Image:Gemini Observatory/AURA/NRC

More follow-up observations, with other telescope networks around the world including the European Very Long Baseline Interferometry (VLBI) Network, showed that the various FRB signals were occurring within 100 light years of each other. Astronomers also identified a fainter, continuous radio source, that also seems to be co-located.

“We think that the bursts and the continuous source are likely to be either the same object or that they are somehow physically associated with each other,” Benito Marcote, a research at the of the Joint Institute for VLBI ERIC in the Netherlands, said in a statement.

So, now that we know where all the intergalactic chatter is coming from, can we say what’s causing it? Not yet—but the location of FRB 121102 within a dim dwarf galaxy does imply one rather badass possibility: a magnetar. That’s an insanely dense, rapidly rotating dead star with a magnetic field powerful enough to shred the entire cosmic neighborhood to atoms.

“I favor the idea that they’re related to magnetars,” Williams said. He noted that dim dwarf galaxies, such as the one which birthed FRB 121102, also happen to be associated with another weird cosmic phenomenon— super-luminous supernovae. Nobody’s really sure why the brightest stellar explosions are happing in the dimmest galaxies, but there’s reason to suspect such environments might also be conducive to the formation of magnetars. Alternatively, the signal could be associated with an “active galactic nucleus,” with radio jets coming from material surrounding the galaxy’s supermassive black hole.

My personal pet theory is that the galaxy is dim because an advanced alien civilization has built a Starkiller Base-esque contraption to systematically suck the life out of the stars, and that said alien death machine releases powerful energy bursts every time it knocks off another non-compliant planet. But according to scientists, I shouldn’t get too attached to this idea.

“We’ve joked about spaceship battles and death stars blowing up, but we think we can explain it with ordinary physics,” Chatterjee said.

[Nature]

Maddie is the science editor at Gizmodo

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NASA INASA Is Actually Going to Visit That Insane Metallic Worlds Actually Going to Visit That Insane Metallic World


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NASA Is Actually Going to Visit That Insane Metallic World

Wednesday 5:15pm

Top image: Artist’s concept of Psyche, NASA/JPL

There’s nothing quite like Psyche anywhere else in our solar system—a small asteroid belt object made entirely of iron-nickel metal. Which is why NASAhas decided to send a probe to check out the bizarre beast up close.

“Human kind has visited rocky worlds and icy worlds, but we’ve never seen a metal world,” Lindy Elkins-Tanton, principal investigator for the Psyche Mission, which NASA just green-lit as part of its ongoing Discovery program, told reporters in a press call this afternoon. “Psyche’s appearance remains a mystery. This will be true exploration and discovery.”

Measuring just 130 miles (210 kilometers) in diameter, the giant hunk of space ore known as 16 Psyche is located in our solar system’s main asteroid belt, three times further from the sun than Earth is. It’s believed to be the stripped core of a small planet destroyed in the very early days of our solar system. Visiting a world like Psyche could offer scientists a chance to learn more about the mysterious interiors of terrestrial planets, including Earth’s—which is one of the reasons NASA has decided to push forward with this somewhat offbeat mission.

“The pressure at Earth’s core is over 3 million times air pressure. We are never going to Earth’s core,” Elkins-Tanton said. “Psyche lets us visit inner space by visiting outer space.”

Another very compelling to visit Psyche: space mining.

“I think one of the most important things we’ll discover are what are the surface conditions on a metal asteroid are like,” Elkins-Tanton continued, noting that Psyche’s surface could tell us a lot about how easy or difficult it would be to mine such an asteroid in the future.

Psyche is one of two missions NASA has just selected, from five finalists announced last year, to receive Discovery-class funding. The other mission, called Lucy, will visit a main-belt asteroid, followed by six of the so-called Trojan asteroids located in the vicinity of Jupiter. The Trojans are a motley collection of space rocks influenced by Jupiter’s prodigious gravity, and their diverse composition is thought to hold clues to the formation of the solar system.

Potential formation mechanisms for Psyche. Image: Lindy Elkins-Tanton et. al / 46th Lunar and Planetary Science Conference (2015) via USRA

Lucy and Psyche will launch in 2021 and 2023, respectively. Lucy will make its first asteroid rendezvous in 2025, and spend the next few years Trojan-hopping around Jupiter, using newer versions of the instruments included on NASA’s New Horizons mission to Pluto.

Psyche is targeted to arrive at its metallic destination in 2030. The mission will orbit 16 Psyche for 20 months, taking images, measuring magnetic field strength and gravity, and determining the asteroid’s precise composition.

Lucy and Psyche are the thirteenth and fourteenth Discovery-class missions. They follow in the footsteps of some of NASA’s most exciting recent expeditions, including the Dawn mission to Ceres, and the OSIRIS-Rex mission to asteroid Bennu.

Maddie is the science editor at Gizmodo

The Most Detailed View of Black Holes in the Universe Will Blow Your Mind


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The Most Detailed View of Black Holes in the Universe Will Blow Your Mind

Yesterday 4:25pm

Image: NASA/CXC/Penn State/B.Luo et al.

Stare into the abyss, my friends. The image above features the highest concentration of black holes humans have ever seen. So dense are the merciless chasms of darkness at the center of this map, you could pack 5,000 of them into a patch of sky the size of the full moon.

So… why do they look like a bunch of Christmas baubles? Good question. This image represents a portion of the Deep Field South Survey—the deepest x-ray glimpse of our universe ever, collected through nearly 12 weeks of observing with the Chandra telescope, NASA’s flagship space-based x-ray hunter. While black holes themselves emit no light, interstellar gases heat up as they approach the singularity’s point of no return (called the event horizon), yielding bursts of high-energy x-rays.

Measuring those x-rays gives Chandra a way to fingerprint black holes, and to track their formation and evolution throughout the history of the universe. The light is then redshifted down into the visible part of the spectrum, so that our squishy human brains can process it in order to glean information and better ponder the fragility of existence. (Redder colors represent lower-energy x-rays, while bluer colors indicate higher-energy emissions.)

The entire Deep Field South Survey, which was published today in conjunction with a press conference at the 229th meeting of the American Astronomical Society, contains over a thousand black holes. The image shown here represents the central portion, where the black holes are most dense. The faint pinpricks of light at the very center include black holes up to 12.5 billion light years from Earth, which is to say, on other side of the known universe.

Ultra-deep field surveys like this are offering insights into how supermassive black holes grow—mostly in bursts, it seems, from “seeds” weighing anywhere between 10,000 and 100,000 solar masses. But many mysteries about black holes remain, including how the supermassive variety found at the centers of galaxies are able to consume enough matter to rapidly achieve masses billions of times that of our Sun.

Sure gives you something to chew on.

[Chandra]

Maddie is the science editor at Gizmodo

NASA Animation Offers a Freakishly Accurate Look at This Year’s Coast-to-Coast Eclipse


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NASA Animation Offers a Freakishly Accurate Look at This Year’s Coast-to-Coast Eclipse

On August 21st, a shadow produced by a total solar eclipse will travel from the USA’s Pacific coast right through to the Atlantic coast—something that hasn’t happened in nearly 100 years. A new NASA animation shows where you’ll need to be to catch this once-in-a-lifetime event.

NASA visualization artist Ernie Wright created this animation using an array of datasets, including information collected by the Lunar Reconnaissance Orbiterand the SRTM topography project.

Wright had to factor in a tremendous number of variables, including the positions of the Earth, Moon, and Sun, along with changing elevations along the path of totality (the band within which a total solar eclipse can be observed). It’s the most accurate simulation ever produced of a total solar eclipse, showing the irregular and ever-changing shape of the moon’s shadow.

Image: NASA

Indeed, the shape of the penumbra (the shaded outer region of the shadow) is not what’s typically expected from an object as seemingly geometric as the Moon. The penumbra is irregularly shaped because the edge of the moon, or limb, is also irregularly shaped. The shadows produced along the moon’s jagged peaks and valleys is exaggerated by the angle of reflection, and by Earth’s surface features such as mountains and valleys. Combined, the effect is a shadow that looks more like a polygon than an oval.

As mentioned, the eclipse is scheduled to occur on August 21st. Thankfully, that’s plenty of time for those of us outside of the path to organize a road trip.

Correction: A previous version of this article had the incorrect date for the eclipse.

George is a contributing editor at Gizmodo and io9.