Starship Asterisk*

SOFIA's Southern Lights

Explanation: SOFIA, the Stratospheric Observatory for Infrared Astronomy, is a Boeing 747SP aircraft modified to carry a large reflecting telescope into the stratosphere. The ability of the airborne facility to climb above about 99 percent of Earth's infrared-blocking atmosphere has allowed researchers to observe from almost anywhere over the planet. On a science mission flying deep into the southern auroral oval, astronomer Ian Griffin, director of New Zealand’s Otago Museum, captured this view from the observatory's south facing starboard side on July 17. Bright star Canopus shines in the southern night above curtains of aurora australis, or southern lights. The plane was flying far south of New Zealand at the time at roughly 62 degrees southern latitude. Unfortunately, after a landing at Christchurch severe weather damaged SOFIA requiring repairs and the cancellation of the remainder of its final southern hemisphere deployment.

<< Previous APOD

This Day in APOD

Next APOD >>

Aurora Australis! Lovely aurora's are always protecting us from
harmful radiation! Thanks SOFIA!

orin stepanek wrote: ↑Fri Jul 29, 2022 11:39 am ASC05954-Edit1024.jpg
Aurora Australis! Lovely aurora's are always protecting us from
harmful radiation! Thanks SOFIA! 8-)

The auroras don't protect us, they just make visible the magnetic fields that do.

Chris Peterson wrote: ↑Fri Jul 29, 2022 1:38 pm

orin stepanek wrote: ↑Fri Jul 29, 2022 11:39 am ASC05954-Edit1024.jpg
Aurora Australis! Lovely aurora's are always protecting us from
harmful radiation! Thanks SOFIA!

The auroras don't protect us, they just make visible the magnetic fields that do.

Yes, You're right; thanks for catching that! It is nice that the lights are there to remind us!

orin stepanek wrote: ↑Fri Jul 29, 2022 1:45 pm

Chris Peterson wrote: ↑Fri Jul 29, 2022 1:38 pm

orin stepanek wrote: ↑Fri Jul 29, 2022 11:39 am ASC05954-Edit1024.jpg
Aurora Australis! Lovely aurora's are always protecting us from
harmful radiation! Thanks SOFIA!

The auroras don't protect us, they just make visible the magnetic fields that do.

Yes, You're right; thanks for catching that! It is nice that the lights are there to remind us!

Those coloured lights do disperse the energy of solar wind protons; the air particles at the altitude of 90 to 150 km intercepts those particles, potentially harmful.
Still if those air particles did not shine (for example, were not there, or let the solar wind protons pass without a fight), we would still have some air layers above to defend us; that would not be so beautiful — the low atmosphere being too thick to fluorescence — but nevertheless effective.
Who should thank the polar lights for saving their lives are high altitude uni-cell extremophiles.

VictorBorun wrote: ↑Fri Jul 29, 2022 4:29 pm

orin stepanek wrote: ↑Fri Jul 29, 2022 1:45 pm

Chris Peterson wrote: ↑Fri Jul 29, 2022 1:38 pm

The auroras don't protect us, they just make visible the magnetic fields that do.

Yes, You're right; thanks for catching that! It is nice that the lights are there to remind us!

Those coloured lights do disperse the energy of solar wind protons; the air particles at the altitude of 90 to 150 km intercepts those particles, potentially harmful.
Still if those air particles did not shine (for example, were not there, or let the solar wind protons pass without a fight), we would still have some air layers above to defend us; that would not be so beautiful — the low atmosphere being too thick to fluorescence — but nevertheless effective.
Who should thank the polar lights for saving their lives are high altitude uni-cell extremophiles.

Well, if we really want to be technical, it's still not the lights that are protecting us, but the absorption of high energy particles by air molecules, after those particles have been concentrated and focused by Earth's magnetic field. The light only indicates that absorption has happened. It would work just as well if the absorbed energy was released as heat, or released outside the visible spectrum, or as radio waves. (Indeed, some of the energy is released in all of those places.)

Beautiful sight! And the "captured this view" link gives a video of the auroras that is incredible. Nice work by astronomer Ian Griffin, using a new auroral camera on SOFIA, so I guess this was actually part of the observing mission, enjoying the aurora.

In the video, one can see a faint red region, sometimes turning more gray, and below that, the bottom visible portion, much brighter and more consistent, are the bands of green. I guess in the APOD still, one can also see the red region, though it is pretty faint.

The view of the plane's wing and engine are intriguing. Apparently illuminated by moonlight. I guess this is the leading edge of the wing and engine (starboard side). Why do they appear bright red?

MarkBour wrote: ↑Fri Jul 29, 2022 5:30 pm The view of the plane's wing and engine are intriguing. Apparently illuminated by moonlight. I guess this is the leading edge of the wing and engine (starboard side). Why do they appear bright red?

Most likely they are lit by the plane's interior red lighting shining out the windows.