Galactic Weather Discovery Changes Our Understanding of the Solar System

The Interstellar Boundary Explorer, or IBEX, has provided NASA with a completely unexpected view of solar winds. Turns out that these "winds" of charged particles are shaped by nearby stars. This discovery completely changes our picture of the solar system.

Scientists are using IBEX to create a more accurate map of the boundary between interstellar space and our heliosphere - the bubble of space created by solar winds from our sun. This bubble shields the planets from cosmic particles that zoom from interstellar space towards the sun at speeds ranging from 100,000 mph to more than 2.4 million mph. What scientists thought they'd find was a boundary between the heliosphere and interstellar space that was fairly regular and shifted gradually from one region to the other. But instead they discovered that the charged particles streaming out of our sun are a distinctive ribbon shape (the blue and red regions in the heliosphere model above), almost like an intense jet stream moving rapidly through the solar system.

Said Dr. David J. McComas, IBEX principal investigator:

The IBEX results are truly remarkable, with emissions not resembling any of the current theories or models of this never-before-seen region. We expected to see small, gradual spatial variations at the interstellar boundary, some ten billion miles away. However, IBEX is showing us a very narrow ribbon that is two to three times brighter than anything else in the sky.

This suggests that in some ways, space weather resembles Earth weather. Except instead of hot fronts and cold fronts, you have the magnetic fields of distant stars changing the shape of solar winds here at home.

Here's a closer look at the ribbon.

Galactic Weather Discovery Changes Our Understanding of the Solar System

One question arose immediately when scientists made this discovery: Why didn't the Voyager spacecraft see this ribbon? It turns out that it flows directly between the two satellites' flight paths (see top image).

Eric Christian, the IBEX deputy mission scientist at NASA's Goddard Space Flight Center, said:

The Voyagers are providing ground truth, but they're missing the most exciting region. It's like having two weather stations that miss the big storm that runs between them.

Looks like we have a destination for the next generation of Voyager-style craft.

Even more exciting is that this solar wind ribbon appears to be highly concentrated in some areas, as if the magnetic fields of our interstellar neighborhood are creating eddies and whirlpools of charged particles. Researchers poring over the IBEX data say they need to spend much more time analyzing what they've found before they can make any definitive statements about what all of this means. But one thing they can say for sure. Our solar system's weather - and by extension our solar system itself - is far more affected by nearby stars than anyone realized before.

via Southwest Research Institute