A team of NASA scientists have reportedly unraveled the mystery of a striking “ribbon” of energy and particles discovered by NASA’s Interstellar Boundary Explorer (IBEX) at the edge of our solar system.
The origins of the ribbon of energy, discovered nearly three years ago, was largely a mystery to astronomers and astrophysics around the world. The edges of our solar system – the boundary at the edge of our heliosphere where material streaming out from the sun interacts with the galactic material – is essentially invisible, according to NASA. It emits no light and no conventional telescope can see it. Yet, particles from inside the solar system bounce off this boundary and neutral atoms from that collision stream inward. Those particles can be observed by instruments and since those atoms act as fingerprints for the boundary from which they came, astronomers can map that boundary in a way never before done. In 2009, IBEX discovered something in that map that no one could explain: a vast ribbon dancing across this boundary that produced many more energetic neutral atoms than the surrounding areas.
Now, in a paper published inAstrophysical Journal, a team of internationals researchers led by lead author Nathan Schwadron of the University of New Hampshire, propose a “retention theory” that for the first time explains all the key observations of this astrophysical enigma.
“If the theory is correct,” Schwadron noted in a statement released through the university, “the ribbon can be used to tell us how we’re moving through the magnetic fields of the interstellar medium and how those magnetic fields then influence our space environment.”
The so-called “retention theory” proposes the ribbon exists in a special location where neutral hydrogen atoms from the solar wind move across the local galactic magnetic field. Neutral atoms are not affected by magnetic fields, but when their electrons get stripped away they become charged ions and begin to gyrate rapidly around magnetic field lines. The rapid rotation results in waves or vibrations in the magnetic field, and the charged ions then become trapped by the waves — ultimately, creating the ribbons of energy observed by astronomers.
Schwadron likens the effect to boats in a harbor.
“Think of the ribbon as a harbor and the solar wind particles it contains as boats. The boats can be trapped in the harbor if the ocean waves outside it are powerful enough. This is the nature of the new ribbon model. The ribbon is a region where particles, originally from the solar wind, become trapped or ‘retained’ due to intense waves and vibrations in the magnetic field,” says Schwadron.
While the theory has long been proposed, it did contain a number of loopholes that astronomers have struggled to explain. The U.S. space agency noted that astronomers did not know what processes at the edge of the solar system could cause this mysterious increase in neutral atoms, or why any part of the boundary was different than other areas in the solar system. In the years since, astronomers took time to create models and theories to try to explain the ribbon and now, building on earlier interpretations scientists have added a new hypothesis to help solve thy mystery.