APOD: STEVE over Copper Harbor (2021 May 05)

[APOD Robot]

STEVE over Copper Harbor

Explanation: What creates STEVEs? Strong Thermal Emission Velocity Enhancements (STEVEs) have likely been seen since antiquity, but only in the past five years has it been realized that their colors and shapes make them different from auroras. Seen as single bright streaks of pink and purple, the origin of STEVEs remain an active topic of research. STEVEs may be related to subauroral ion drifts (SAIDs), a supersonic river of hot atmospheric ions. For reasons currently unknown, STEVEs are frequently accompanied by green "picket-fence" auroras. The featured STEVE image is a combination of foreground and background exposures taken consecutively in mid-March from Copper Harbor, Michigan, USA. This bright STEVE lasted several minutes, spanned from horizon to horizon, and appeared in between times of normal auroras.

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[RocketRon]

Have these been observed from the ISS at all ?
If they are aligned East-West, this is also a product of the earths magnetic field ?
But where does the heat come from ??

Fabulous photo of a really strange and as yet unexplained phenomenon ...

[Ann]

Lets have a look at some of the background stars, clusters and nebulas!

1) Procyon

2) Beehive Cluster

3) Rosette Nebula (the Cone Nebula and Christmas Tree cluster are to the upper right of the Rosette)

4) Pollux

5) Castor

6) Messier 35

7) Capella

8) Maybe Betelgeuse?

Ann

[orin stepanek]

Every once in a while you learn something New!
I must confess; I never heard of Steve
before, except as a guy's name! My Dad's middle
name!

[Chris Peterson]

Have these been observed from the ISS at all ?
If they are aligned East-West, this is also a product of the earths magnetic field ?
But where does the heat come from ??

Heat (in this context) is a form of kinetic energy. The particles are very energetic and moving very fast, which means they are hot. By definition. It's not unlike the part of the atmosphere where the ISS orbits (the thermosphere). The temperature of the tenuous gas that surrounds it is well over 1000 K. But you'd still freeze to death if you were in the shadows.

[NCTom]

This an awesome photo. Great that the photographer was ready at the right time with the right equipment.

[bystander]

Every once in a while you learn something New!
I must confess; I never heard of Steve
before, except as a guy's name! My Dad's middle
name!

STEVE first appeared on APOD on 2017 Oct 14 and again on 2020 Nov 17.

[asjkdfshad]

...spanned from horizon to horizon...

The feature appears to dissipate at the top of the image.

Does it faintly continue in a giant loop and return to the horizon, (another horizon)?

Sorry if a little pedantic: Can there be two horizons?

[WWW]

Here's another interesting article on STEVEs research:
http://www.sci-news.com/othersciences/g ... 07137.html

[VictorBorun]

Here's another interesting article on STEVEs research:
http://www.sci-news.com/othersciences/g ... 07137.html

This pic is rather confusing.

Click to view full size image

The SAID ring (with a STEVE segment) around the polar magnetic field is shown as just an insulating gap between the higher plasma and solar wind region (green) and the lower plasmasphere (blue).
It would have been more dramatic if there were a major decline or increase in the polar magnetic field before and after a polar light, and the change were so dramatic as to induce circular electric current along the SAID ring heating the ionized air up and making it glow at STEVE segments.

[VictorBorun]

STEVE and starry background MaryBeth Kiczenski.png

4) Pollux
5) Castor
Ann

Any chance that the North pole or a magnetic pole is the center of this STEVE arc?

[Ann]

STEVE and starry background MaryBeth Kiczenski.png

4) Pollux
5) Castor
Ann

Any chance that the North pole or a magnetic pole is the center of this STEVE arc?

This particular STEVE passes right between Pollux and Castor in Gemini. That means that it isn't pointing in the direction of Polaris at all.

Ann

[Chris Peterson]

STEVE and starry background MaryBeth Kiczenski.png

4) Pollux
5) Castor
Ann

Any chance that the North pole or a magnetic pole is the center of this STEVE arc?

This particular STEVE passes right between Pollux and Castor in Gemini. That means that it isn't pointing in the direction of Polaris at all.

It shouldn't be pointing towards Polaris or the nearby magnetic pole. It should be perpendicular to a line of RA, since it's nominally an arc with its center at the magnetic pole. That is consistent with lying between the Twins.

[VictorBorun]

ok I am happy.
In fact I was trying to ask if the steve could have been an arc of a ring centered on the magnetic pole. But the curvature should be hard to judge.
At 450 km distance an arc of a ring at 47°28′08″N which has cosine = 0.68 and radius = 4300 km is pretty straight

[Leon]

why does the light of the feature extend (in front of) the landscape feature?/