Astroblog: A Ring Around The Moon

Saturday, October 31, 2009

A Ring Around The Moon

Jupiter forms the jewel in this ring around the Moon (click to embiggen)

Even on cloudy nights you can see interesting things, I captured this image of a ring around the Moon on a night you might have thought was a waste of time. Technically its a 22 degree halo, not a ring, and fortuitously the halo arc was so close to Jupiter that it looked like a Jewel in the ring. In the original you can see a little colour in the halo.

22 Degree halos are the commonest kind of halo or arc, although they are far less obvious than rainbows, and may easily be missed. They are formed by refraction of light through hexagonal columar ice crystals as the fall to the ground. The halo will form when there is a uniform distribution of randomly oriented crystals in the cirrostratus cloud through which the Moon (or Sun) is shining. Because random orientation is only possible if the crystals are tumbling as they fall, the crystals need to be quite small. This is different from what I've been calling "Moonbows", there are typically 8 degrees away from the Moon, and are caused by bullet shaped crystals.

So not only are you seeing something pretty, you are seeing a dynamic event and some cool physics.

Labels: Halo, Moon, Moonbow

# posted by Ian Musgrave @ 7:16 am

Comments:

Delray Beach, Florida
the halo around the moon this evening looked like a rainbow, it was so beautiful
october 30, 2009 approx. 10:45 pm

# posted by

Anonymous : 1:34 pm

Nice.

# posted by

Rob : 4:41 pm

Im from Asheville, NC. My girlfriend and I went outside around 3:00am on Nov. 2, 2009 and we saw the most BEAUTIFUL RAINBOWS EVER!!! There were TWO COMPLETE RAINBOWS around the Moon! I/we hgve NEVER seen or experienced such BEAUTY like thgt before especially at night. DAYENA DABNER & MELANIE RAMSEY

# posted by

Anonymous : 12:46 pm

Today Nov. 30,2009 I was outside with my kids and my husband and we saw the most amazin g thing it was like a rainbow around the moon. My son is actually studying the moon right now for school so it was a good to expirience something new and at the same time my son learned something.

# posted by

Unknown : 2:38 pm

I live in Ft. Laud. FL, and saw the Halo on 11/30/09...what an awesome sight! it was amazing to see the beautiful rings around the moon, and how large it was...and how bright the sky was, you can see all the stars in the sky.

# posted by

Unknown : 3:16 pm

Here in Clearwater Florida, last night Dec 1 at midnight, my boyfriend and I stepped outside and saw a beautiful colored huge halo, yellow with red orange around the moon. Never saw anything so amazing...once in a life time.
DELILAH & CHUCK

# posted by

Anonymous : 12:37 am

Boynton Beach, Fl
A ring around the moon tonight...

# posted by

Anonymous : 2:50 pm

Just saw the same tonight 3/24/10 in Sarasota FL!

# posted by

Unknown : 11:42 am

FROM (PAHOKEE ,FL) YESTERDAY I SEEN THE RING AROUND THE MOON AND I BEEN WAITING TO SEE IT AGAIN EVER SINCE NOVEMBER 2009. I HAVENT SEEN IT SINCE THEN UNTIL YESTERDAY . IT WAS SO BEAUITFUL.ITS A LOVELY SIGHT WITH YOUR SOULMATE UNDER THE STARS

# posted by

LILA14 : 4:26 am

Feb.8.2012 that ring may mean something else

# posted by

Anonymous : 5:23 pm

I have seen rings round the moon, but the night before Hurricane Sandy hit I saw an unusual one. The moon was not centered in the ring, it was on the edge of it and there was an arc over the moon that looked like a faint rainbow. The ring around the moon was so large that it took up half the sky. Only God could create such beauty!

# posted by

Anonymous : 1:58 am

ring around moon and moon not in the center... moon in upper right corner still inside the ring... why?????????

# posted by

Anonymous : 11:57 am

It was strange in Las Vegas to see the burnt orange halo around the full moon tonight.

# posted by

Anonymous : 3:48 pm