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APOD: Little Planet Aurora (2023 Nov 25)
Posted: Sat Nov 25, 2023 5:06 am
by APOD Robot
Little Planet Aurora
Explanation: Immersed in an eerie greenish light, this rugged
little planet appears to be home to stunning water falls and an impossibly tall mountain.
It's planet Earth of course. On the night of November 9 the nadir-centered 360 degree mosaic was
captured by digital camera from the
Kirkjufell mountain area of western Iceland. Curtains of
shimmering Aurora Borealis or Northern Lights provide the pale greenish illumination. The intense auroral display was caused by solar activity that rocked
Earth's magnetosphere in early November and produced strong geomagnetic storms. Kirkjufell mountain itself stands at the top of the
stereographic projection's circular horizon. Northern hemisphere skygazers will recognize the familiar stars of the Big Dipper just above Kirkjufell's peak. At lower right the compact Pleiades star cluster and truly giant
planet Jupiter also shine in this little planet's night sky.
Re: APOD: Little Planet Aurora (2023 Nov 25)
Posted: Sat Nov 25, 2023 2:59 pm
by SeedsofEarfth
The lines of the aurora are reminiscent of magnetic flux lines, arcing out from the poles just as they do on the ends of a magnet. Is there any relationship between those aurora lines and Earth's magnetic flux lines?
Re: APOD: Little Planet Aurora (2023 Nov 25)
Posted: Sat Nov 25, 2023 9:38 pm
by johnnydeep
SeedsofEarfth wrote: ↑Sat Nov 25, 2023 2:59 pm
The lines of the aurora are reminiscent of magnetic flux lines, arcing out from the poles just as they do on the ends of a magnet. Is there any relationship between those aurora lines and Earth's magnetic flux lines?
Not sure. The aurora is certainly caused by Earth's magnetic field, but whether or not the strong resemblance here to the shape of those field lines (looping from pole to pole) is revealing that is unclear to me. It may just be a trick caused by the stereographic projection. Chris?
Re: APOD: Little Planet Aurora (2023 Nov 25)
Posted: Sat Nov 25, 2023 9:57 pm
by Chris Peterson
johnnydeep wrote: ↑Sat Nov 25, 2023 9:38 pm
SeedsofEarfth wrote: ↑Sat Nov 25, 2023 2:59 pm
The lines of the aurora are reminiscent of magnetic flux lines, arcing out from the poles just as they do on the ends of a magnet. Is there any relationship between those aurora lines and Earth's magnetic flux lines?
Not sure. The aurora is certainly caused by Earth's magnetic field, but whether or not the strong resemblance here to the shape of those field lines (looping from pole to pole) is revealing that. It may just be a trick caused by the stereographic projection. Chris?
While the charged particles that create auroras certainly travel along magnetic field lines, I do think this largely an illusion here. Superficially this image looks like the lines around a bar magnet- a dipole field with a north and a south. But the south magnetic pole is not close to being visible here!
Re: APOD: Little Planet Aurora (2023 Nov 25)
Posted: Sat Nov 25, 2023 11:26 pm
by johnnydeep
Chris Peterson wrote: ↑Sat Nov 25, 2023 9:57 pm
johnnydeep wrote: ↑Sat Nov 25, 2023 9:38 pm
SeedsofEarfth wrote: ↑Sat Nov 25, 2023 2:59 pm
The lines of the aurora are reminiscent of magnetic flux lines, arcing out from the poles just as they do on the ends of a magnet. Is there any relationship between those aurora lines and Earth's magnetic flux lines?
Not sure. The aurora is certainly caused by Earth's magnetic field, but whether or not the strong resemblance here to the shape of those field lines (looping from pole to pole) is revealing that is unclear to me. It may just be a trick caused by the stereographic projection. Chris?
While the charged particles that create auroras certainly travel along magnetic field lines, I do think this largely an illusion here. Superficially this image looks like the lines around a bar magnet- a dipole field with a north and a south. But the south magnetic pole is not close to being visible here!
Ah, thanks. Good point!