Starship Asterisk*

Posted: **Mon Aug 30, 2021 4:06 am**

A Fire Rainbow over West Virginia

Explanation: What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds present below -- in this case cirrus fibrates. The numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are somewhat unusual to see. The featured fire rainbow was photographed earlier this month near North Fork Mountain in West Virginia, USA.

<< Previous APOD

This Day in APOD

Next APOD >>

Posted: **Mon Aug 30, 2021 5:38 am**

: A Fire Rainbow over West Virginia. Image Credit: Christa Harbig

Amazing! It looks like the sky is ablaze with a wildfire of color!

Ann

Posted: **Mon Aug 30, 2021 12:15 pm**

I'm not sure I understand the phrase "the Sun must be at least 58 degrees high in a sky where cirrus clouds present below"...

Was the photographer looking up at the sky or was he on a mountain looking level or down?

Posted: **Mon Aug 30, 2021 12:39 pm**

Exactly what I was thinking Ann! The Sky is burning; Aka Henny Penny
The sky is falling! I never knew this phenom existed!

Kitty thinks it's amazing also

Posted: **Mon Aug 30, 2021 12:59 pm**

FrankTKO wrote: ↑Mon Aug 30, 2021 12:15 pm
I'm not sure I understand the phrase "the Sun must be at least 58 degrees high in a sky where cirrus clouds present below"...

Was the photographer looking up at the sky or was he on a mountain looking level or down?

Looking up at the cirrus.
http://www.atoptics.co.uk/halo/chaform.htm
http://www.atoptics.co.uk/halo/cha2.htm
http://asterisk.apod.com/viewtopic.php? ... 73#p292326

Posted: **Mon Aug 30, 2021 3:49 pm**

Of course all that is true! pass the ice cold one.

Posted: **Mon Aug 30, 2021 8:14 pm**

Ann wrote: ↑Mon Aug 30, 2021 5:38 am
A Fire Rainbow over West Virginia. Image Credit: Christa Harbig

Amazing! It looks like the sky is ablaze with a wildfire of color!

Ann

I fully concur ...

Click to play embedded YouTube video.

As Riker says in Star Trek, but due to something quite else.

Posted: **Mon Aug 30, 2021 10:13 pm**

It is nice to have ONE planet where we can get close-ups!

Posted: **Mon Aug 30, 2021 10:15 pm**

heehaw wrote: ↑Mon Aug 30, 2021 10:13 pm It is nice to have ONE planet where we can get close-ups!

I think it's fair to say that, at the moment, we have two (although with less geographical coverage on one of those).

Posted: **Mon Aug 30, 2021 10:44 pm**

Click to play embedded YouTube video.

Chris Peterson wrote: ↑Mon Aug 30, 2021 10:15 pm
heehaw wrote: ↑Mon Aug 30, 2021 10:13 pm

It is nice to have ONE planet where we can get close-ups!
I think it's fair to say that, at the moment, we have two (although with less geographical coverage on one of those).

Starship Asterisk*

APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)

Re: APOD: A Fire Rainbow over West Virginia (2021 Aug 30)