APOD: Alaskan Moondogs (2016 Mar 21)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 3549
Joined: Fri Dec 04, 2009 3:27 am

APOD: Alaskan Moondogs (2016 Mar 21)

Post by APOD Robot » Mon Mar 21, 2016 4:08 am

Image Alaskan Moondogs

Explanation: What's happened to the sky? Moonlight illuminates a snowy scene in this night land and skyscape made on 2013 January from Lower Miller Creek, Alaska, USA. Overexposed near the mountainous western horizon is the first quarter Moon itself, surrounded by an icy halo and flanked left and right by moondogs. Sometimes called mock moons, a more scientific name for the luminous apparitions is paraselenae (plural). Analogous to a sundog or parhelion, a paraselene is produced by moonlight refracted through thin, hexagonal, plate-shaped ice crystals in high cirrus clouds. As determined by the crystal geometry, paraselenae are seen at an angle of 22 degrees or more from the Moon. Compared to the bright lunar disk, paraselenae are faint and easier to spot when the Moon is low.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

User avatar
Beyond
500 Gigaderps
Posts: 6889
Joined: Tue Aug 04, 2009 11:09 am
Location: BEYONDER LAND

Re: APOD: Alaskan Moondogs (2016 Mar 21)

Post by Beyond » Mon Mar 21, 2016 4:16 am

Finally! Something to howl at the earth, for a change.
To find the Truth, you must go Beyond.

Boomer12k
:---[===] *
Posts: 2485
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: Alaskan Moondogs (2016 Mar 21)

Post by Boomer12k » Mon Mar 21, 2016 8:13 am

Really nice shot...

:---[===] *

heehaw

Re: APOD: Alaskan Moondogs (2016 Mar 21)

Post by heehaw » Mon Mar 21, 2016 8:45 am

What's happened to the Earth? Look at those glints on the snow!

User avatar
RJN
Baffled Boffin
Posts: 1491
Joined: Sat Jul 24, 2004 1:58 pm
Location: Michigan Tech

Re: APOD: Alaskan Moondogs (2016 Mar 21)

Post by RJN » Mon Mar 21, 2016 2:47 pm

I deleted the reference to cirrus clouds in the NASA APOD text since there are likely few cirrus clouds between the observer and the mountain. I apologize for the oversight. - RJN

starsurfer
Stellar Cartographer
Posts: 3529
Joined: Thu Mar 15, 2012 7:25 pm

Re: APOD: Alaskan Moondogs (2016 Mar 21)

Post by starsurfer » Mon Mar 21, 2016 2:50 pm

This is very nice, I have seen sundogs but never moondogs. I think Moonlady will like this one. :)