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The Mystery of the "Space Roar"

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In 2009, scientists at NASA's Goddard Space Flight Center sent a machine called ARCADE into space on a giant balloon, in search of radiation from the universe's earliest stars. ARCADE (Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission) carried seven sensors that picked up electromagnetic radiation like radio waves. The plan was to lift it far enough up to prevent the Earth's atmosphere from interfering. Then, the finely-tuned instrument could detect faint radio signals from ancient stars.

Instead, ARCADE detected a huge amount of radio noise—six times louder than scientists had predicted—which has since come to be known as the "space roar." And while there are some theories, we still don't know what's causing it.

Space Sounds

Of course, space isn't roaring in any way that our ears could hear. But there are objects in the universe—including some galaxies—which emit radio waves via synchrotron radiation.

According to Dale Fixsen, a University of Maryland research scientist and a member of the ARCADE team, NASA had built devices that detected radio noise before. These worked by looking at one point in the sky, and then at another nearby one for contrast. These instruments were useful for detecting radio-emitting galaxies and supernovas, because they measured the difference between two points. But they couldn't detect the roar.

"If there's a uniform source [of synchrotron radiation], those instruments are blind to it," Fixsen tells mental_floss.

On the other hand, ARCADE used a "large beam" that searched 7 percent of the sky. Because of the large area it searched, and its high-precision sensors, it was the first instrument we've built that could discover the roar.

But it couldn't find out everything. Fixsen says that synchrotron radiation has a characteristic spectrum. And since every source of the radiation displays this same spectrum, ARCADE couldn't discover what was roaring.

Roar Theories

Fixsen says that synchrotron radiation usually comes hand in hand with infrared radiation. We've already measured the amount of infrared radiation that the Milky Way emits with the COBE satellite, and according to Fixsen, with our galaxy's level of infrared, it doesn't look like the Milky Way is the source of the synchrotron radiation for the "space roar."

"The relationship is tight for all galaxies we've measured," Fixsen says. "It should hold true for our galaxy as well."

On the other hand, theorists think that we've detected almost all the sources of this radiation outside our galaxy. And we know that none of these sources is causing the "roar."

According to Fixsen, there are a few possible explanations. First, the "roar" could be coming from the earliest stars. The first stars didn't have any dust—because the first dust in the universe was formed within those stars. This could have let those stars create a lot of synchrotron radiation, without a correspondingly high amount of infrared.

Second, the radiation might be coming from gases in large clusters of galaxies—Fixsen says that it would be difficult for the instruments we've used up until now to detect radiation from these.

Third, it could be coming from dim, but extremely plentiful, radio galaxies. Individually, they would be too quiet for us to detect, but en masse they might be loud enough to create the "roar."

Future plans

But while there are some plausible theories, we still don't have any data to tell us which one is right. Fixsen says that there's been talk about flying ARCADE again (it's currently living in the Goddard Space Flight Center). Or they might use an instrument on the ground next time; Fixsen says they could use the data from the ARCADE mission to calibrate it, and avoid interference from the atmosphere.

But for now, what NASA wrote in its 2009 press release is still true: "The source of this cosmic radio background remains a mystery."

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Pop Culture
Neil deGrasse Tyson Recruits George R.R. Martin to Work on His New Video Game
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Kevin Winter / Getty Images

George R.R. Martin has been keeping busy with the latest installment of his Song of Ice and Fire series, but that doesn’t mean he has no time for side projects. As The Daily Beast reports, the fantasy author is taking a departure from novel-writing to work on a video game helmed by Neil deGrasse Tyson.

DeGrasse Tyson’s game, titled Space Odyssey, is currently seeking funding on Kickstarter. He envisions an interactive, desktop experience that will allow players to create and explore their own planets while learning about physics at the same time. To do this correctly, he and his team are working with some of the brightest minds in science like Bill Nye, former NASA astronaut Mike Massimino, and astrophysicist Charles Liu. The list of collaborators also includes a few unexpected names—like Martin, the man who gave us Game of Thrones.

Though Martin has more experience writing about dragons in Westeros than robots in outer space, deGrasse Tyson believes his world-building skills will be essential to the project. “For me [with] Game of Thrones ... I like that they’re creating a world that needs to be self-consistent,” deGrasse Tyson told The Daily Beast. “Create any world you want, just make it self-consistent, and base it on something accessible. I’m a big fan of Mark Twain’s quote: ‘First get your facts straight. Then distort them at your leisure.’”

Other giants from the worlds of science fiction and fantasy, including Neil Gaiman and Len Wein (co-creator of Marvel's Wolverine character), have signed on to help with that same part of the process. The campaign for Space Odyssey has until Saturday, July 29 to reach its $314,159 funding goal—of which it has already raised more than $278,000. If the video game gets completed, you can expect it to be the nerdiest Neil deGrasse Tyson project since his audiobook with LeVar Burton.

[h/t The Daily Beast]

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Space
Flying Telescopes Will Watch the Total Solar Eclipse from the Air

If you've ever stood on the tips of your toes to reach something on a high shelf, you get it: Sometimes a little extra height makes all the difference. Although in this case, we're talking miles, not inches, as scientists are sending telescopes up on airplanes to monitor conditions on the Sun and Mercury during the upcoming total eclipse.

Weather permitting, the Great American Eclipse (as some are calling it) will be at least partially visible from anywhere in the continental U.S. on August 21. It will be the first time an eclipse has been so widely visible in the U.S. since 1918 and represents an incredible opportunity not only for amateur sky-watchers but also for scientists from coast to coast.

But why settle for gawking from the ground when there's an even better view up in the sky?

Scientists at the Southwest Research Institute (SwRI) have announced plans to mount monitoring equipment on NASA research planes. The telescopes, which contain super-sensitive, high-speed, and infrared cameras, will rise 50,000 feet (about 9.5 miles) above the Earth's surface to sneak a very special peek at the goings-on in our Sun and its nearest planetary buddy.

Gaining altitude will not only bring the instruments closer to their targets but should also help them avoid the meteorological chaos down below.

"Being above the weather guarantees perfect observing conditions, while being above more than 90 percent of Earth's atmosphere gives us much better image quality than on the ground," SwRI co-investigator Constantine Tsang said in a statement. "This mobile platform also allows us to chase the eclipse shadow, giving us over seven minutes of totality between the two planes, compared to just two minutes and 40 seconds for a stationary observer on the ground."

The darkness of that shadow will blot out much of the Sun's overpowering daily brightness, giving researchers a glimpse at rarely seen solar emissions.

"By looking for high-speed motion in the solar corona, we hope to understand what makes it so hot," senior investigator Amir Caspi said. "It's millions of degrees Celsius—hundreds of times hotter than the visible surface below. In addition, the corona is one of the major sources of electromagnetic storms here at Earth. These phenomena damage satellites, cause power grid blackouts, and disrupt communication and GPS signals, so it's important to better understand them."

The temporary blackout will also create fine conditions for peeping at Mercury's night side. Tsang says, "How the temperature changes across the surface gives us information about the thermophysical properties of Mercury's soil, down to depths of about a few centimeters—something that has never been measured before."

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