Halo around the Moon

Our closest neighbor.
btoman
Posts: 208
Joined: October 12th, 2009, 10:35 pm
Location: Baton Rouge

Halo around the Moon

Post by btoman »

If you get outside on one of these chilly nights and the sky is clear, you may get to see one of these. Formed by light reflecting on ice crystals high in the atmosphere, I suspect these halos are not as common down here in Louisiana as they were up in cold, wintry Michigan. There is a nice one out there right now so I'm going to get away from the computer and go freeze a little!
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

Absolutely the best lunar halo I'd ever seen.

Lunar halos form when light gets refracted by ice crystals inside or near cirrostratus clouds, or other clouds that are high in altitude and thin. A 22 degree halo is a ring of light 22 degrees from the Moon or the Sun and is the most common halo. Strong halos can have bands of color.

More information at:
http://ww2010.atmos.uiuc.edu/(Gh)/guide ... lo/22.rxml
http://hyperphysics.phy-astr.gsu.edu/hb ... nhalo.html
http://curious.astro.cornell.edu/question.php?number=79

Nice March 2003 pic:
http://apod.nasa.gov/apod/ap030321.html

Nice December 2009 pic:
http://epod.usra.edu/blog/2010/03/lunar ... aurus.html
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

Here's a nice one. It was taken at an Illinois park in December 2009 when the Moon was in Taurus; one can see Aldebaran to the lower right, between the Moon and the halo. Also, it looks like Orion is swinging from the bottom of the halo!

There's a bright spot in the center of the Moon, which I guess is the most overexposed part of the image.

Image:
http://epod.usra.edu/blog/2010/03/lunar ... aurus.html
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

Those six-sided crystals are at it again. Today's APOD is Rafael Schmall's capture of a halo around the Moon on 2 February south of Budapest. Both Aldebaran and the Pleiades can be seen within the halo.

The image:
http://apod.nasa.gov/apod/ap120211.html
LesleyLandry
Posts: 1
Joined: August 24th, 2012, 3:58 am

Re: Halo around the Moon

Post by LesleyLandry »

The halo is amazing, especially in winter, on a frosty might. I really enjoy walking under the full moon and watching it in the sky.
Thank you for explaining this phenomenon. Although it ruins the romance it is really interesting.
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

Halos during the winter are fantastic. But unless my eyes deceived me I just saw a halo outside. The Moon is a waxing gibbous at the time, so it surprises me. It might be a "false" halo, if there's such a thing, due to the thin clouds, but it sure looks like one. A nice final sky treat before Isaac shut down the celestial show for the next couple of days.
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

Friday's APOD is Luis Argerich's interesting submission of a halo around this last Supermoon. It was taken near Buenos Aires. Due to exposure time, it looks like a sunrise instead of a moonrise, but it's beautiful.

28 June APOD:
http://apod.nasa.gov/apod/ap130628.html
Christopher K.
Posts: 5640
Joined: October 12th, 2009, 3:28 pm
Location: Baton Rouge, LA

Re: Halo around the Moon

Post by Christopher K. »

My first halo of the season! I viewed it just now with Ben, Ashley and Roslyn here at HRPO. The Moon is 10.65 days old; I'm not sure if that's a personal record for least-illuminated Moon generating a complete halo. It certainly is the "fuzziest" halo I've since thanks to the thin clouds.
fred8615
Posts: 294
Joined: October 12th, 2009, 12:29 pm
Location: Sorrento, LA

Re: Halo around the Moon

Post by fred8615 »

Christopher K. wrote:My first halo of the season! I viewed it just now with Ben, Ashley and Roslyn here at HRPO. The Moon is 10.65 days old; I'm not sure if that's a personal record for least-illuminated Moon generating a complete halo. It certainly is the "fuzziest" halo I've since thanks to the thin clouds.
Pics, or it didn't happen. :lol:
Frederick J. Barnett
"Someone's got to take the responsibility if the job's going to get done!! Do you think that's easy?!" Gregory Peck - The Guns Of Navarone
Poppa-Chris
Posts: 110
Joined: December 13th, 2012, 5:32 pm
Location: Denham Springs, LA

Re: Halo around the Moon

Post by Poppa-Chris »

I'm with you, Fred. Where is the evidence! :lol:
Poppa-Chris


"First star to the right, then straight on until morning!" - Peter Pan
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