This is a huge surprise and it
really underscores the reality that the sun and all its planets are powerful
magnetic dynamos.
We will be using this capability
to travel throughout the solar system using magnetic field exclusion vessels on
which I have written and posted extensively.
We now know that a combination of weakening fields and complex magnetic
bubbles will make travel into and beyond this barrier rather problematic.
It also provides a natural
boundary for Solar Space itself that is defined and natural. Outer space begins out past the froth.
A Big Surprise from the Edge of the Solar System
June 9, 2011: NASA's Voyager probes are truly going where no one has gone before. Gliding silently toward the stars, 9 billion miles from Earth, they are beaming back news from the most distant, unexplored reaches of the solar system.
It's bubbly out there.
"The Voyager probes appear to have entered a strange realm of
frothy magnetic bubbles," says astronomer Merav Opher of Boston University .
"This is very surprising."
A NASA video shows
how magnetic bubbles might be formed at the edge of the solar system.
According to computer models, the bubbles are large, about 100 million
miles wide, so it would take the speedy probes weeks to cross just one of them.
Voyager 1 entered the "foam-zone" around 2007, and Voyager 2 followed
about a year later. At first researchers didn't understand what the Voyagers
were sensing--but now they have a good idea.
"The sun's magnetic field extends all the way to the edge of the
solar system," explains Opher. "Because the sun spins, its magnetic
field becomes twisted and wrinkled, a bit like a ballerina's skirt. Far, far
away from the sun, where the Voyagers are now, the folds of the skirt bunch
up."
Magnetic bubbles at the edge of the solar system are about 100 million
miles wide--similar to the distance between Earth and the sun.
When a magnetic field gets severely folded like this, interesting
things can happen. Lines of magnetic force criss-cross and
"reconnect". (Magnetic reconnection is the same energetic process
underlying solar flares.) The crowded folds of the skirt reorganize themselves,
sometimes explosively, into foamy magnetic bubbles.
"We never expected to find such a foam at the edge of the solar
system, but there it is!" says Opher's colleague, University of Maryland
physicist Jim Drake.
Theories dating back to the 1950s had predicted a very different
scenario: The distant magnetic field of the sun was supposed to curve around in
relatively graceful arcs, eventually folding back to rejoin the sun. The actual
bubbles appear to be self-contained and substantially disconnected from the
broader solar magnetic field.
Energetic particle sensor readings suggest that the Voyagers are
occasionally dipping in and out of the foam—so there might be regions where the
old ideas still hold. But there is no question that old models alone cannot
explain what the Voyagers have found.
Says Drake: "We are still trying to wrap our minds around the
implications of these findings."
The structure of the sun's distant magnetic field—foam vs. no-foam—is
of acute scientific importance because it defines how we interact with the rest
of the galaxy. Researchers call the region where the Voyagers are now "the
heliosheath." It is essentially the border crossing between the Solar
System and the rest of the Milky Way. Lots of things try to get
across—interstellar clouds, knots of galactic magnetism, cosmic rays and so on.
Will these intruders encounter a riot of bubbly magnetism (the new view) or
graceful lines of magnetic force leading back to the sun (the old view)?
Old and new views of the heliosheath. Red and blue spirals are the
gracefully curving magnetic field lines of orthodox models. New data from
Voyager add a magnetic froth (inset) to the mix.
The case of cosmic rays is illustrative. Galactic cosmic rays are
subatomic particles accelerated to near-light speed by distant black holes and
supernova explosions. When these microscopic cannonballs try to enter the solar
system, they have to fight through the sun's magnetic field to reach the inner
planets.
"The magnetic bubbles could be our first line of defense against
cosmic rays," points out Opher. "We haven't figured out yet if this
is a good thing or not."
On one hand, the bubbles would seem to be a very porous shield,
allowing many cosmic rays through the gaps. On the other hand, cosmic rays
could get trapped inside the bubbles, which would make the froth a very good
shield indeed.
"We'll probably discover which is correct as the Voyagers proceed
deeper into the froth and learn more about its organization1," says Opher.
"This is just the beginning, and I predict more surprises ahead."
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