Narrator: Scientists have now spotted signs of a structured boundary between
the sun and the rest of the solar system. The sun is
not a hard ball in space, nor is it a giant ball of
fire. Instead, it's a mass of charged particles and magnetic
fields. This material extends outward, flowing beyond the surface
of the sun, creating an atmosphere that spreads throughout our
solar system. But the transition is not perfectly seamless.
Our star can be characterized into layers. Each region
has its own temperature ranges and special properties. We call the sun's
atmosphere the corona. The steady breeze of
particles flowing out from the sun and filling the space between the planets
is the solar wind. New research indicates that there is a
discernible transition between the corona and the solar wind.
This difference is marked by a visible change in the consistency
of solar material departing the sun.
About 20 million miles out from the sun, the very nature of the solar material
changes, and the sun's magnetic field no longer
controls its movement. At this point, the flow becomes more
turbulent. Like water from a squirt gun, the plasma
starts as a stream, but then breaks into drops. The farther out
it goes, the weaker the sun's magnetic control of the material, and
the less clear its form becomes. To find this transition,
scientists took images of the faint solar wind and used an
algorithm to dim the competing brightness of background stars and
dust. These are the first movies of the solar wind
itself in a previously unmapped region,
helping us understand what's flowing from the sun, through the space
around our planet and out to the edges of our solar system--crucial
information as we continue to explore.
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