EOS/University of New Hampshire

ScienceShot: How to Tie a Ribbon Round the Solar System

Dick writes about Earth and planetary science for Science magazine.

More than 3 years ago, stunned space physicists reported the discovery of a narrow band of sky lit up in the cameras of the Interstellar Boundary Explorer (IBEX) like some Milky Way on fire. High-powered hydrogen atoms, rather than light, were streaming toward the Earth-orbiting spacecraft from near where the sun's wind of charged particles encounters the magnetic field that courses between the stars. A dozen theories later, a pair of IBEX researchers report this week in The Astrophysical Journal that the interstellar magnetic field (thin gray lines wrapping around the region filled by solar wind) may be temporarily trapping and concentrating out-bound particles. The trapping would be most effective where the solar wind squarely crosses interstellar magnetic field lines (gray "life preserver"). IBEX would "see" particles that escape the trap in the sun's direction as the ribbon, here rendered in reds, yellows, and greens. The craft should thoroughly test the trapping idea as the sun's activity varies in the years ahead.

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Posted in Space