STRANGE LIGHT IN EARLY NIGHT SKY

STRANGE LIGHT IN EARLY NIGHT SKY 

of Sunday 29.SEPT.2103 AROUND 8 PM

 

 FOR MORE RECENT EXPLANATION OF THE EVENT READ THE ARTICLE AT:

https://sites.google.com/site/astronomyintanzania/previousmonthsnightskies/october-night-skies-over-tanzania-2013

Indeed, it was fortunate that I also saw the event so I know what people saw.  I was watching the planets Venus, Saturn and Mercury with a group of stargazers on the terrace of a high building in the Dar es Salaam city center, so several people whom I was with also saw it around 8 pm and we were all amazed by the sight and were wondering what could have caused it.  I have tried to think about what could have happened.

 

I will first describe what I saw myself.  The whole sky was absolutely clear.  I saw it first as a small whitish circular disk, rising from the horizon from around 8 pm in the south direction where it was relatively dark.

 

The circle rose steadily, moving towards the north direction and become a larger whitish cloudy disk as it rose in the sky.  

 

I saw that in the middle of the circle there was a small point of light like a star, and the point was moving steadily with the cloudy disk.  The disk became elongated when it reached high in the sky and, three or four minutes after it first rose, the cloud disappeared from sight while high in the sky.

 

Since there was a moving point of light that moved in the centre with the cloud, it looked like a satellite to me.  

 

I have checked in the data that show which satellites are visible in the night sky (http://www.heavens-above.com/) and have seen that there was indeed a satellite that would fit the one that we saw.  

 

It must have been the Resurs DK-1 satellite which rose above the horizon from 7:44 pm in the south and disappeared high in the sky at 42 degrees above the horizon in the south east direction at 7:47 pm.  See table below derived from the data: 


RESURS DK-1

3.1

19:44:11

10°

S

19:47:05

42°

SSE

19:47:05

42°

SSE

 

Satellites are seen soon after sunset (or just before sunrise) because, though the sky becomes dark, the light from the Sun can still strike the satellite which reflects the light and we see it as a moving point of light.  Since it was quite late after sunset (around 8 pm) the only very high satellites can be lit by the sun when it is so low under the horizon.

 

Circular cloud formations can occur due high moisture which causes icy crystals to form in the upper atmosphere or very hazy clouds that we cannot see with our eyes since they are high in the stratosphere .  

 

Such icy crystals due to high moisture causes light to scatter equally in all directions.  Since the source was a tiny lighted point this can produce a circular cloudy view like a halo surrounding the satellite.

 

Similar cloudy ring can be seen surrounding a bright full Moon when there is a lot of moisture in the sky.  

 

We perhaps did not know it yesterday night but the moisture must have built up sufficiently since yesterday to cause the heavy rains today, though it had been absolutely dry during the past days.

 FOR MORE RECENT EXPLANATION OF THE EVENT READ THE ARTICLE AT:

https://sites.google.com/site/astronomyintanzania/previousmonthsnightskies/october-night-skies-over-tanzania-2013


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