August 15, 2013
Has Voyager 1 Finally Left The Solar System? New Analysis Reveals Compelling Evidence
Brett Smith for redOrbit.com - Your Universe Online
According to a new analysis from scientists at the University of Maryland, NASA's Voyager 1 has finally left the Solar System – marking the first time a man-made object has entered the Milky Way outside of the Sun’s influence.
"It's a somewhat controversial view, but we think Voyager has finally left the Solar System, and is truly beginning its travels through the Milky Way," said study author Marc Swisdak, a UMD plasma physicist.
According to the team’s report in The Astrophysical Journal Letters, their model of the outer edge of the Solar System indicates that Voyager 1 entered interstellar space about one year ago. The report contradicts a NASA-backed studies the said the craft is still in a transitional zone on the edge of the Sun’s influence.
“The model described in the paper is new and different from other models used so far to explain the data the spacecraft has been sending back from more than 11 billion miles away from our sun,” the space agency said in a statement that made the case for a different model of the Solar System’s edge.
Data from Voyager 1 recently showed signs that the craft was crossing through the outermost layer of the heliosphere, or region of space filled with the Sun’s magnetic field and charged particles. Voyager reportedly made "multiple crossings of a boundary unlike anything previously observed,” project scientists said.
The probe recorded several dips in the number of solar particles it was observing, which corresponded with sharp increases in galactic electrons and protons found in interstellar space. A month after these anomalous readings, solar particle counts stopped and only galactic particle counts remained. However, Voyager 1 did not record a change in the direction of the magnetic field it was observing.
To explain these findings, researchers in the latest study focused on magnetic reconnection, or the breaking and reconnecting of close and opposing magnetic field lines. In addition to affecting solar flares and other events on the surface of the sun, the UMD researchers said magnetic reconnections occur at the edge of the Solar System, forming magnetic ‘islands’ where galactic cosmic rays mix with solar particles.
The UMD researchers assert that these magnetic reconnections explain why Voyager 1 is detecting galactic particles, but not a change in magnetic field.
In response to the new study, NASA released a statement quoting Voyager project scientist Ed Stone, of the California Institute of Technology in Pasadena.
"Details of a new model have just been published that lead the scientists who created the model to argue that NASA's Voyager 1 spacecraft data can be consistent with entering interstellar space in 2012,” Stone said. “In describing on a fine scale how magnetic field lines from the sun and magnetic field lines from interstellar space can connect to each other, they conclude Voyager 1 has been detecting the interstellar magnetic field since July 27, 2012. Their model would mean that the interstellar magnetic field direction is the same as that which originates from our sun.”
“Other models envision the interstellar magnetic field draped around our solar bubble and predict that the direction of the interstellar magnetic field is different from the solar magnetic field inside,” Stone continued. “By that interpretation, Voyager 1 would still be inside our solar bubble.”
“The fine-scale magnetic connection model will become part of the discussion among scientists as they try to reconcile what may be happening on a fine scale with what happens on a larger scale,” Stone concluded. “The Voyager 1 spacecraft is exploring a region no spacecraft has ever been to before. We will continue to look for any further developments over the coming months and years as Voyager explores an uncharted frontier.”