(AP Photo/NASA / June 27, 2013)
Like Earth's magnetosphere, which shields us from radioactive solar winds, the heliosphere shields the solar system from many of the cosmic rays that fill interstellar space.
Scientists had long envisioned its outermost layer, the heliosheath, to be a curved, distinct boundary separating the solar system from the rest of the Milky Way. They theorized that once Voyager 1 crossed that threshold, three things would happen: The sun's solar winds would become still; galactic cosmic rays would bombard Voyager from every angle; and the direction of the dominant magnetic field would change significantly because it would be coming from interstellar space, not the sun.
All of those predictions have been turned on their head by Voyager's latest instrument readings.
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