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Tuesday, January 09, 2007

Phases of the Moon

 
I've added the phases of the moon to the bottom of the left sidebar. This is in response to a request from somone who is really interested in astronomy and really interested in knowing whether my mood is affected by the phases of the moon. (It isn't, by the way. )

Some examples of the phases of the moon are shown below for viewing from Canada or Chile. Can you tell which is which? Do you know why they're different?

CURRENT MOON

CURRENT MOON

6 comments :

Anonymous said...

Judging by the underlying pattern of the moon and which bits are lit and which ones aren't at that particular time, I'd suggest they're different because they're not right ;-)

Anonymous said...

I'd suggest they're different because they're not right...

Yep. Definitely not.

If the intention is to represent the fact that, if you represent the moon as being 'the right way up' as seen from the given latitude (with the top part being closest to the zenith), if you're going to flip the shadow, you also have to flip the moon itself, so the same hemisphere is shown as shadowed or lit.

... and ... ummm... I'm pretty sure it's the bottom one that's wrong. Seeing as the first quarter normally looks like my photo below, which would make the top waning gibbous about correct: http://www.well.com/~ajmilne/photos_moon/moon_26_6_2001_b.html

Nandes said...

I'm going to assume that the top one is Canada and that they're different because we're in different hemispheres.

Chileans would have their backs in a different direction to face the moon if it lies in between our 2 viewpoints.

?

Jane said...

The top moon is the right one. Yet another example of astronomy education where the lesson is in the right spirit, but it comes out "not quite right".

Equally interesting is the view of Orion from Chile... he's standing on his head, very disorienting.

Larry Moran said...

Dear Jane,

This is a situation where an expert in astronomy should write to the author of the "phases of the moon" and point out the error. (hint, hint) :-)

As far as I can tell, the bottom image is dead wrong. One of the most important criteria in teaching science to the general public is getting it right.

Larry Moran said...

UPDATE: The Southern Hemisphere moon now seems to be correct.