Moon Halo in Karachi – Pakistan
From my childhood I was obsessed by Moon, the largest celestial object that could be seen in sky at night. The reason I was obsessed with it could be, it is in sky for most part of a month. I did not get any useful information and guidance to Astronomy until I found a book of Science in which there was some discussion on Stars, Sun, and the Planets including Moon. Later in that year, I found a book named ‘Stars and Planets’ when I was roaming around in book shops finding a book on Bonsai. I turned the pages randomly and stopped to a page (page # 22) where there was picture of Moon as seen with Naked-eye, Binoculars and Telescope, basically a comparison shown with a picture. Gradually my interest grew and, henceforth the hobby started.
Man in the Moon
I used to observe Moon while going to and coming from Mosque, tried to resolve the mystery of black patches but by then I got the book and read it and found some of the answers. At that time I used to have a Binoculars, that were quite useless but due to the passion, I tried to observe the Moon through it in evening. I could make a face in it. 2 black patches (Mare Serenitatis and Mare Tranquillitatis) are eyes and Mare Vaporum, the nose, and then an open mouth (Mare Nubium).
The Observation – Moon Halo
“By day and by night, the interaction of sunlight and moisture in our atmosphere creates delightful sights in the sky (Practical Skywatching)”
It was Eid-ul-Azha (1st or 2nd Day), 28th November 2009 when I went upstairs at my roof with my brother and their friends. It was almost an hour after Magrib prayers. I looked at the Moon and found something different. But I instantly recalled what I learned from the book ‘Practical Skywatching’ (Thanks to Zain for introducing that book to me). And yes I concluded and shouted “Look at the Moon, it is Moon Halo”. My brother and his friends all looked at the Moon with mouths wide open and admitted that yes there is something different about Moon tonight. It looked something like that (see below picture):
I explained them the phenomenon that it is a rare event and is caused by the Moon light (of course the light of Sun being reflected by the moon) that passes the ice crystals in atmosphere layer, and by refraction a ring around the Moon is created. I messaged instantly to Zain, Imran Bhai and Khalid Sahab about the event. I was so excited that I called up Imran Bhai, wished him Eid-Mubarak and then asked him to go outside and observe the phenomenon. I concluded that this phenomenon is rare, is quite different as it is very much unpredictable and has many elements and factors like moon, temperature, the atmosphere, weather and optical illusion. I could not take the picture as I didn’t have a camera. Nokia 6600 camera didn’t work for photographing the Moon Halo.
Facts about Moon Halo
You don’t need any specific Astronomical Instrument (Binoculars or Telescope). All you need is your eye and good timing, as Moon Halos are not predictable like other astronomical events such as Solar Eclipse, Lunar Eclipse, opposition, transit. Moon Halo is observable but varies from region to region depending upon the temperature, and atmosphere at a certain place.
How Moon Halo is created
The Moon halo which is usually created is of 22degrees. It occurs because of the phenomenon of refraction that happens in the hexagonal ice crystals present in the air (Hyperphysics: Moon Halo).
Don’t confuse Moon Halo with Moon Corona
One might see an outline around moon on some nights just as in the following figure and sometimes at times when there are too many small patches of clouds.
This is a phenomenon known as Moon corona, they are produced when light comes on thin clouds which are small and the whole circular area is also lighted up as seen in figure. On the other hand, in Moon Halo, the circular area is not much lighted up and the circular area is large.
I enjoyed looking at the Moon Halo and wishing to see it again. There are lots of other interesting phenomenon that occurs in the night sky.