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On Its Way to Interstellar Space, Voyager 1 Explores the Magnetic Highway

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This image shows NASA's Voyager 1 spacecraft exploring a new region in our solar system called the "magnetic highway." Image credit: NASA/JPL-Caltech

When NASA launched its Voyager 1 and 2 spacecraft 33 years ago, the probes' primary mission was to explore Jupiter and Saturn. But the two satellites have performed above and beyond their original duty: As of March 2012, Voyager 2 was 14.7 billion kilometers away from Earth, in the heliosheath—the outermost layer of the heliosphere where the solar wind is slowed by the pressure of interstellar gas—and yesterday, at the American Geophysical Union meeting in San Francisco, scientists reported that Voyager 2 has entered a new region at the edge of our solar system, which they believe is the final area the spacecraft has to cross before hitting interstellar space: a magnetic highway for charged particles.

Scientists call this region a magnetic highway because of the connection between our sun's magnetic field lines and interstellar magnetic field lines, which allows lower-energy charged particles from our heliosphere to zoom out into interstellar space, and higher-energy particles from outside to come in. Before Voyager 1 entered this region for the first time on July 28, the charged particles bounced in all directions, "as if trapped on local roads inside the heliosphere," according to a NASA press release. The region ebbed and flowed toward Voyager 1 several times before the craft entered it again on August 25; the environment has since been stable. The magnetic highway is still inside our solar system, scientist believe, the because the direction of the magnetic field lines haven't changed. (The Voyager probes are sending data back to NASA's Jet Propulsion Laboratory through the Deep Space Network, or DSN.)

"Although Voyager 1 still is inside the sun's environment, we now can taste what it's like on the outside because the particles are zipping in and out on this magnetic highway," said Edward Stone, Voyager project scientist based at the California Institute of Technology, Pasadena. "We believe this is the last leg of our journey to interstellar space. Our best guess is it's likely just a few months to a couple years away. The new region isn't what we expected, but we've come to expect the unexpected from Voyager."

So what's it like on this magnetic highway? Voyager 1 reports back that solar winds have slowed to zero, and the magnetic field is about 10 times more intense than before the termination shock, which it crossed in December 2004.

Here's a fun animation, courtesy of NASA, of Voyager 1 on the magnetic highway:

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Brown University Library, Wikipedia/Public Domain
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This Just In
Lincoln’s Famous Letter of Condolence to a Grieving Mother Was Likely Penned by His Secretary
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Brown University Library, Wikipedia/Public Domain

Despite his lack of formal schooling, Abraham Lincoln was a famously eloquent writer. One of his most renowned compositions is the so-called “Bixby letter,” a short yet poignant missive the president sent a widow in Boston who was believed to have lost five sons during the Civil War. But as Newsweek reports, new research published in the journal Digital Scholarship in the Humanities [PDF] suggests that Lincoln’s private secretary and assistant, John Hay, actually composed the dispatch.

The letter to Lydia Bixby was written in November 1864 at the request of William Shouler, the adjutant general of Massachusetts, and state governor John Albion Andrew. “I feel how weak and fruitless must be any word of mine which should attempt to beguile you from the grief of a loss so overwhelming,” it read. “But I cannot refrain from tendering you the consolation that may be found in the thanks of the Republic they died to save.”

Unknown to Lincoln, Bixby had actually only lost two sons in battle; the others had deserted the army, were honorably discharged, or died a prisoner of war. Nevertheless, word of the compassionate presidential gesture spread when the Boston Evening Transcript reprinted a copy of the 139-word letter for all to read.

Nobody quite knows what happened to Bixby’s original letter—some say she was a Confederate sympathizer and immediately burnt it—but for years, scholars debated whether Hay was its true author.

During Hay’s lifetime, the former secretary-turned-statesman had reportedly told several people in confidence that he—not Lincoln—had written the renowned composition, TIME reports. The rumor spread after Hay's death, but some experts interpreted the admission to mean that Hay had transcribed the letter, or had copied it from a draft.

To answer the question once and for all, a team of forensic linguists in England used a text analysis technique called n-gram tracing, which identifies the frequency of linguistic sequences in a short piece of writing to determine its true author. They tested 500 texts by Hay and 500 by Lincoln before analyzing the Bixby letter, the researchers explained in a statement quoted by Newsweek.

“Nearly 90 percent of the time, the method identified Hay as the author of the letter, with the analysis being inconclusive in the rest of the cases,” the linguists concluded.

According to Atlas Obscura, the team plans to present its findings at the International Corpus Linguistics Conference, which will take place at England’s University of Birmingham from Monday, July 24 to Friday, July 28.

[h/t Newsweek]

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science
These Deep-Sea Worms Could Live More Than a Thousand Years

Plunge below the sparkling surface of the Gulf of Mexico, head down into the depths, and there you'll find the ancient ones, growing in clusters of drab tubes like piles of construction equipment. Scientists writing in the journal The Science of Nature report that some of these worms could be more than 1000 years old.

When it comes to marine organisms, the deeper you go, the slower and older life gets. Biologists have found an octopus that guarded her eggs for four and a half years. They've seen clams born during the Ming dynasty and sharks older than the United States. They've seen communities of coral that have been around for millennia.

Previous studies have shown that some species of tube worm can live to be 250 years old. To find out if the same was true for other species—in this case, the Gulf of Mexico's Escarpia laminata—researchers spent years watching them grow. They used a long-lasting dye called Acid Blue to mark six clusters of worms, then let them to go about their wormy business. A year later, they collected all 356 blue-stained tubes and brought them back to the lab to measure their growth.

By calculating the speed of the worms' growth and comparing it to the size of the largest individuals, the scientists could devise a pretty good estimate of the oldest worms' age.

And boy, are they old. The researchers' worm-growth simulation suggested that the most ancient individuals could be more than 9000 years old. This seems incredible, even for tough old tube worms, so the scientists calculated a more conservative maximum age: a mere 1000 years.

A millennium-long lifespan is an extreme and not the average, the paper authors note. "There may indeed be large E. laminata over 1000 years old in nature, but given our research, we are more confident reporting a life span of at least 250 to 300 years," lead author Alanna Durkin of Temple University told New Scientist.

Still, Durkin says, "E. laminata is pushing the bounds of what we thought was possible for longevity."

She's excited by the prospect of finding older creatures yet.

"It's possible that new record-breaking life spans will be discovered in the deep sea,” she says, “since we are finding new species and new habitats almost every time we send down a submersible.”

 

[h/t New Scientist]

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