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Brief fluctuations in Earth’s magnetic field have been detected before many earthquakes in the past 50 years

Friedemann Freund, a crystallographer at San Jose State University

in the weeks before a magnitude-5.4 quake struck about 15 kilometers northeast of San Jose in October 2007, an instrument near the epicenter sensed a number of unusual magnetic pulses

Those blips became more frequent as the day of the earthquake approached, Freund says

recently, prior to several medium- to moderate-sized quakes in Peru, two sensitive magnetometers recorded the same sort of pulses

how such pulses could be generated

suggest that these blips stem from microscopic changes in crystals in rocks under seismic stress deep within Earth

In many types of rocks, particularly volcanic rocks that have substantial amounts of water locked inside them, crystals are chock-full of oxygen-oxygen bonds called peroxy bonds

(These bonds formed long ago, after chemical changes split some of the water molecules, freeing the hydrogen atoms to bond together and then diffuse out of the rocks as gas.)

When those rocks are squeezed, say, by the sides of a fault zone scraping past one another, some of the peroxy bonds break

Those broken bonds release negatively charged electrons, which remain trapped in place, and create positively charged “holes” in the crystal

his team propose that the same process might be happening within Earth’s crust

As stress on large volumes of rock builds in advance of an impending quake, many, many of these electrical holes are created inside them

the mass migration of such holes that creates the large electrical currents responsible for generating the low-frequency magnetic pulses that make their way to detectors on Earth’s surface

they say

some critics of his model have proposed

lightning

as an alternative explanation

he notes, with data from the two sensors in Peru he and his colleagues were able to pinpoint the strongest of those pulses as originating within a few kilometers of the epicenters of subsequent quakes

For now, Freund admits, the team’s model is preliminary: The paper has been submitted to a journal and is now being reviewed by other scientists.

two instruments aren’t sufficient to pinpoint the location of an event; to truly “triangulate” an event you need at least three sensors

“I’m concerned that the pulses are not originating deep within the Earth.”

“This paper only makes sense if the observations [of magnetic pulses] are good,”

John Ebel, a seismologist at Boston College, who wasn’t involved in the research

the blips may have some inexplicable humanmade origin

Decades ago

his Boston-based magnetometers started picking up a series of odd pulses every morning.

Eventually

identified

It was the engineers cranking up Boston’s trolley cars at a rail yard a few kilometers away from the instruments

Even if the magnetic pulses originate within Earth along seismic zones under stress, Freund says, the blips don’t always foretell a quake

It’s more likely to be the pattern of pulses—and, in particular, changes in their size and frequency—that Freund and his colleagues say might offer scientists a crystal ball for impending temblors

The content of the message will be determined by whomever wants to participate in the planet-wide project

The message itself will be transmitted sometime after New Horizons does a flyby of Pluto in 2015 and sends back the scientific data that it collects

If all goes according to plan, New Horizons will become the fifth man-made object to travel beyond the solar system—after Pioneers 10 and 11 and Voyagers 1 and 2.

it's the only one of the five not to launch with a message for any alien travelers it might encounter along the way

The Pioneer spacecrafts bore plaques on their sides, and the Voyagers each carried golden records (and the means to play them).

When New Horizons' journey was being planned

other missions had been scrapped and the budget was extremely tight

didn't have the bandwidth for

the message

. "Now

It doesn't cost massive amounts because there's no hardware, just uplinking ones and zeroes

Lomberg, who worked closely with Carl Sagan on the Voyager golden record in 1977, had an epiphany last year about sending the message digitally

In September 2013, Lomberg launched a website with a petition to NASA. By February 2014, 10,000 people from over 140 countries had signed it.

Lomberg approached Stern, who advised him that NASA would need evidence of public support

This message will be very different from the one Lomberg designed with Sagan almost 40 years ago

The 21st-century version will be a global self-portrait, pieced together by many willing hands

Anyone on Earth will be able to upload potential content (images, sounds, software—the formats haven't been finalized)

Then everyone will be able to vote on what to include

"Our team is going to provide the overall architecture of the message," says Lomberg, "but we'll try to keep ourselves open to what we will send."

, a National Geographic emerging explorer

will have to figure out how to wrangle a planet's worth of opinions into the roughly 100 MB of memory New Horizons will have available on its computer.

the project will officially launch August 25, the final file may not be sent for several years

The New Horizons computer won't have any room in its memory until the data from Pluto are transmitted back to Earth, which could take more than a year

"The spacecraft is so far away," says Lomberg, "that download times are like dial-up Internet."

Pluto may not be the final mission target

hopes that the spacecraft will have a shot at a flyby of another object in the Kuiper Belt of the solar system

If that happens, the message upload will be delayed

As long as the spacecraft is healthy and the radio is working," he says, "there's no particular rush to send it

cosmic radiation may eventually corrupt the spacecraft's electronic memory

The New Horizons message won't last nearly as long as the metal missives attached to Pioneer and Voyager will

Ed Stone of the California Institute of Technology

But when our sun has a burst, it sends a shock wave outward that reaches Voyager about a year later. The wave causes the plasma surrounding the spacecraft to sing."

Data from this newest tsunami wave generated by our sun confirm that Voyager is in interstellar space

The mission has not left the solar system—it has yet to reach a final halo of comets surrounding our sun—but it broke through the wind-blown bubble, or heliosphere, encasing our sun

ur sun goes through periods of increased activity, where it explosively ejects material from its surface, flinging it outward

These events, called coronal mass ejections, generate shock, or pressure, waves. Three such waves have reached Voyager 1 since it entered interstellar space in 2012

The first was too small to be noticed when it occurred and was only discovered later, but the second was clearly registered by the spacecraft's cosmic ray instrument in March of 2013

another instrument on Voyager

The plasma wave instrument can detect oscillations of the plasma electrons

This ringing of the plasma bell is what led to the key evidence showing Voyager had entered interstellar space

"The tsunami wave rings the plasma like a bell," said Stone. "While the plasma wave instrument lets us measure the frequency of this ringing, the cosmic ray instrument reveals what struck the bell—the shock wave from the sun."

denser plasma oscillates faster, the team was able to figure out the density of the plasma

In 2013, thanks to the second tsunami wave, the team acquired evidence that Voyager had been flying for more than a year through plasma that was 40 times denser than measured before—a telltale indicator of interstellar space

Now, the team has new readings from a third wave from the sun, first registered in March of this year

These data show that the density of the plasma is similar to what was measured previously, confirming the spacecraft is in interstellar space