Invisible Portals Let Sun’s Wind Blow Through Earth’s Hair

A coronal hole shows up as huge dark patch in this photo taken this morning in ultraviolet light by NASA’s Solar Dynamics Observatory. Holes are places where the sun’s magnetic field opens up and allows pent up solar wind to escape. Electrons and protons in the wind can cook up auroras in Earth’s upper atmosphere. Credit: NASA

The sun giveth in so many ways. A high speed wind of particles from a large hole in its outer atmosphere is streaming toward Earth right now and will put the squeeze on our planet’s protective magnetic bubble wrap tomorrow June 30 and Sunday.

Flaring sunspot groups currently crossing the sun will also contribute to the disturbance.

That puts at least minor auroral storms back in the forecast, so be on the lookout. One downer. A bright moon could dilute their visibility.

A NASA-funded researcher has been studying a recently discovered phenomenon called “portals” that connect the sun’s magnetic field with Earth’s, allowing the solar wind direct entry to our upper atmosphere, where it can spark auroras and other geomagnetic storm effects.

Earth’s magnetic field lines (pink) tie in directly with the sun’s (yellow) at portals located in the sun-facing side of our planet’s magnetic bubble. The resulting connection sends solar wind particles straight into the upper atmosphere. Credit: NASA

The sun’s magnetic field, which is bundled with the solar wind’s blizzard of electrons and protons, hooks up with Earth’s at so-called X-points, creating an uninterrupted path between our planet and the sun’s atmosphere. Portals are cylinder-shaped and located about 20,000 miles from Earth toward the sun. Approximately every 8 minutes a portal open up and the two fields connect, allowing particles access to Earth. Most X points are small and come and go quickly, but some are as big as the Earth and long-lived.

When Earth’s and the sun’s fields cross at the X point (right) material can follow our planet’s magnetic lines of force (blue) down into the polar atmosphere to create auroras. Credit: NASA

Earth’s magnetosphere staves off much of the sun’s solar wind, but like a mole in the CIA, a portal allows the wind to get in through the front door. Don’t get too alarmed about them – the sun’s wind’s been blowing for billions of years. No matter how it ultimately enters Earth’s inner sanctum to bless and curse us with geomagnetic storms, we’re still protected by our atmosphere from any direct particle hits.

Photograph of the northern auroral oval during an active geomagnetic storm, when Earth’s magnetic field is energized by particles flowing in the solar wind. Credit: NASA

NASA plans to study the portals in detail when the agency with a series of four satellite due to launch in 2014. Called the Magnetospheric Multiscale Mission (MMS), the probes will fan out and hunt for portals using particle detectors and magnetic sensors.

Scientists are coming to understand that the auroras we so enjoy are stoked by more often by the solar wind popping through portals then trickling around the edges of Earth’s magnetosphere. To learn more, take a look at NASA’s video on the topic.

2 Responses

  1. track

    We are currently living in Virginia Beach, and will be relocating to Duluth…long ago home to my wife…which she is quit excited to be coming back home…as it were. I had considered selling my telescope, a Celestron NexStar8SE, but Karen advised me to hold on to it as the night skies are awesome…so, as an amateur astronomenr, should I pack up my Celestron and tote it to the far north? I have never owned such a nice instrument, and I feel it is quite out of my league, but I have seen some amazing things, and I suppose it can only get better…am I right? What say ye? Inquiring minds want to know?

    1. astrobob

      Absolutely – bring it along! You’ll find dark skies relatively close to town. When you arrive, let me know and I’ll provide you with information about our club, the Arrowhead Astronomical Society.

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