As an amateur astronomer I take a keen interest in what is happening above our heads, but apparently not keen enough!
My mother during a recent telephone call asked if I'd seen the moon the previous day, I answered, "Yes", and asked her why was she asking, because although she does look through my 'scope on the odd occasion, she is no-way as keen as her son. The answer, it turns out, was that there had been a piece in the evening TV news.
What was being discussed was the occurrence of the instant of full moon with the moon being at the closest point in its orbit to the Earth (the perigee of its orbit); this occurred on 12 and 13 December and although not common is not rare. The conjunction of these two phenomena has two results: higher than usual tides (king tides), and the moon appears larger than usual in the sky. Nick Lomb at Sydney Observatory explains all the mechanics in his post for 15 December (www.sydneyobservatory.com.au/blog/?p=1535).
So I don't miss the next, Constant Reader, I give the circumstances of the event, which is the only one for 2009: 10 January (perigee, distance 357,497 km, 10 pm AEST); 11 January (full moon, 2:37 pm AEST).
While checking my facts and figures for the above I noticed that December 2009 will have two full moons. This means the second December full moon (31 December) can be called a blue moon.
Image: The Earth & Moon as seen by the Voyager 1 spacecraft, 18/9/1977. Distance: 7.25 million km. Moon is at 11 o'clock position.
Image credit: © NASA/JPL, 1977.
1 comment:
Peter.
Thanks for your kind comments.
Your Blog is quite impressive.
You have inspired me to do some long overdue updating to mine.
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