Saturday, May 5, 2012

EXTRA: Why you should look at tonight's full moon - and find out for yourself how "super" it really is!

Here we go again: When a full moon in the spring of 2011 coincided with perigee it was hyped as a "supermoon" (using a term introduced by an astrologer), connected with natural disasters (absolute nonsense) - and then widely debunked as a total non-event: no normal person would be able to notice that this moon was closer to Earth than others throughout the year. In time I pointed out on this blog that this claim was also wrong and a pity because it would discourage people from actually finding out for themselves what's going on in the sky.

For this blogger had found out by chance that the ellipticity of the lunar orbit is actually pretty obvious to the naked eye, with perigee full moons easily recognized as such without being told about their closeness beforehand. In the following year I even made a little sport out of guessing the distance of full moons without knowing the numbers, and it worked quite well. To do this properly the Moon has to be reasonably high in the sky and away from distracting foreground objects: the 'moon illusion' must not be allowed to play a role. Just take in the unobstructed sight (and look how much surface detail of the maria one can actually see with the unaided eye, while you're at it).

Tonight we are facing another perigee moon - and wouldn't you believe it, the debunkers in their zeal to kill the 'supermoon' idea repeat the claim that the eye can't see anything without a ruler: NASA does it, also Sky & Telescope does it, many normally reputable astronomy blogs do it. This AP video tops them all by even completely mixing up the perigee effect and the moon illusion in its first minute - yikes! I can only encourage everyone to have a look tonight: of course you're biased now but try to memorize the appearance of the full moon and recall that when viewing more distant ones later in the year (the one in June will still look exactly the same, so don't despair if it's cloudy tonite)! More stories with varying degrees of flawed-ness (and occasional nice numbers and plots) here, here, here, here, here, here, here, hier and hier.

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