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That big ol' moon

For the past few nights the moon has appeared larger than many people have seen it for almost 20 years.
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I don't see what's so special about the last few nights.

If you want to see a large full moon you can do so every month - just look out for it near moonrise or moonset and you'll see it close to the horizon.

All that's happening right now is that it's highest altitude through the night is at a minimum. You can see the moon at a range of altitudes (and apparent sizes) all year round.

Am I missing something?

David
 
Not since June 1987 has the moon been this low in the sky, accentuating the illusion even further.
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But it's "this low in the sky" every night. In fact, it's even lower, at 0 degrees altitude, when it rises and sets.

David
 
As explained in the link I posted, the angular diameter of the moon is approx 0.5 degrees no matter where in the sky it is located. There may be some slight variation throughout the year as the moon moves closer or further from the earth in its orbit, but the angular size is constant from moonrise to moonset on any given night (or day).

The apparent enlargement when near the horizon is an illusion.

I think "low in the sky" may be refering to how far south it is at moonrise. Not that that actually makes any difference.
 
davidhorman said:
But it's "this low in the sky" every night. In fact, it's even lower, at 0 degrees altitude, when it rises and sets.

David
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Maybe the Bad Astronomer will stop by..

I thought they were saying that the current zenith, is as low as it has been in 20 years..
 
According to a colleague, Lloyd Kaufman, various distance cues (height in plane, interposition and the "flat bowl sky" effect) make the horizon moon look further away. Since it has the same retinal image as the moon at the zenith, it appears bigger.
 
I thought they were saying that the current zenith, is as low as it has been in 20 years..
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It is,and as an amateur science geek I can appreciate the cosmological significance of it, but it's hardly the once-in-a-lifetime optical illusion the news people are making it out to be.

David
 
davidhorman said:
All that's happening right now is that it's highest altitude through the night is at a minimum. You can see the moon at a range of altitudes (and apparent sizes) all year round.

Am I missing something?
Click to expand...
If the moon peaks at a low altitude, it spends more time near the horizon where the illusion occurs. When it rises, it doesn't rise straight up, but at a pretty good angle so it's near the horizon longer.
 
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