The edge of the solar system has no edge, it turns out. It has a fuzzy transitional area that is not quite part of our solar system and not quite interstellar space.
This basic fact of our star's environment has been discovered by Voyager 1, one of the most remarkable spaceships ever built. Our premier scout of deep space, Voyager 1 is currently 18 billion km from the sun, beaming data to Earth as it scoots at 60,000 kph toward the constellation Ophiuchus.
Scientists had assumed that Voyager 1, launched in 1977, would have exited the solar system by now. That would mean crossing the heliopause and leaving behind the vast bubble known as the heliosphere, which is characterized by particles flung out by the sun and its powerful magnetic field.
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