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-   -   Not so super 'super' moon... (https://www.weather-banter.co.uk/uk-sci-weather-uk-weather/152804-not-so-super-super-moon.html)

David Allan March 19th 11 06:29 PM

Not so super 'super' moon...
 
Now I don't know about anyone else, but the so-called 'super moon' didn't
look any bigger than loads of other moon rises I've witnessed.
The full-moon at moonrise often appears much bigger (and so does the sun at
sunrise).
OK, so it's also supposed to be closer to us in its orbit to boot, but I
reckon that extra closeness is not THAT close that you're going to be able
to visually notice the difference.
Eye-catcing it was... but no more eye-catching than many another moonrise at
full moon.

Regards... David Allan.



John Hall March 19th 11 06:45 PM

Not so super 'super' moon...
 
In article ,
David Allan writes:
Now I don't know about anyone else, but the so-called 'super moon' didn't
look any bigger than loads of other moon rises I've witnessed.
The full-moon at moonrise often appears much bigger (and so does the sun at
sunrise).
OK, so it's also supposed to be closer to us in its orbit to boot, but I
reckon that extra closeness is not THAT close that you're going to be able
to visually notice the difference.
Eye-catcing it was... but no more eye-catching than many another moonrise at
full moon.


To me, it did seem noticeably larger and brighter than normal. That was
fifteen minutes ago, when it was already well away from the horizon. Of
course it could have been a psychological effect, since I knew that it
was supposed to be "super".
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

I.M.Sutherland March 19th 11 07:05 PM

Not so super 'super' moon...
 
Definitely looks bigger here; commented on this to other half last night
too.


Yokel[_2_] March 19th 11 09:12 PM

Not so super 'super' moon...
 
On 19/03/2011 19:45, John Hall wrote:
In ,
David writes:
Now I don't know about anyone else, but the so-called 'super moon' didn't
look any bigger than loads of other moon rises I've witnessed.
The full-moon at moonrise often appears much bigger (and so does the sun at
sunrise).
OK, so it's also supposed to be closer to us in its orbit to boot, but I
reckon that extra closeness is not THAT close that you're going to be able
to visually notice the difference.
Eye-catcing it was... but no more eye-catching than many another moonrise at
full moon.

To me, it did seem noticeably larger and brighter than normal. That was
fifteen minutes ago, when it was already well away from the horizon. Of
course it could have been a psychological effect, since I knew that it
was supposed to be "super".

There are both real and psychological effects.

The moon's orbit is distinctly elliptical, so the moon's distance varies
significantly as it goes round. This can be shown by looking at solar
eclipses, which vary from the moon being large enough to completely
cover the sun for about 7 minutes at any given point, to "annular"
eclipses when even at mid-eclipse a ring of sunlight is left around the
moon's disk. Of course, the moon passes through "perigee" every month,
but it is only really noticeable when it occurs at full moon and our
satellite is displayed in full sunlit glory.

The shape of the moon's orbit also varies slightly due to gravitational
effects from the changing geometry of earth, moon and sun. This has
resulted in the orbit currently becoming slightly more elliptical than
normal, hence the slightly closer approach highlighted for tonight. The
earth's orbit and angle of the rotation axis also change in this way
over long timescales - these variations affect the distribution of solar
heating over the globe and a gentleman called Milankovitch showed how,
together with "feedback" effects, these variations could partly explain
the pattern of ice ages and interglacials.

The very real psychological effect is that the brain uses various cues
to estimate the size of objects very far away. Experiments with pairs
of drawings have shown that the brain can be "fooled" by a surprising
amount - an object seen close to the horizon providing a "scale" for it
seems larger than one high in the sky. And there have been any number
of incidents which demonstrate beyond all reasonable doubt that people
will believe almost any old tosh - and judge what they see and hear on
this basis - if they do not know or cannot understand the truth.

--
- Yokel -

Yokel posts via a spam-trap account which is not read.


Tudor Hughes March 20th 11 03:56 AM

Not so super 'super' moon...
 
On Mar 19, 10:12*pm, Yokel wrote:

There are both real and psychological effects.

The moon's orbit is distinctly elliptical, so the moon's distance varies
significantly as it goes round. *This can be shown by looking at solar
eclipses, which vary from the moon being large enough to completely
cover the sun for about 7 minutes at any given point, to "annular"
eclipses when even at mid-eclipse a ring of sunlight is left around the
moon's disk. *Of course, the moon passes through "perigee" every month,
but it is only really noticeable when it occurs at full moon and our
satellite is displayed in full sunlit glory.

The shape of the moon's orbit also varies slightly due to gravitational
effects from the changing geometry of earth, moon and sun. *This has
resulted in the orbit currently becoming slightly more elliptical than
normal, hence the slightly closer approach highlighted for tonight. *The
earth's orbit and angle of the rotation axis also change in this way
over long timescales - these variations affect the distribution of solar
heating over the globe and a gentleman called Milankovitch showed how,
together with "feedback" effects, these variations could partly explain
the pattern of ice ages and interglacials.

The very real psychological effect is that the brain uses various cues
to estimate the size of objects very far away. *Experiments with pairs
of drawings have shown that the brain can be "fooled" by a surprising
amount *- an object seen close to the horizon providing a "scale" for it
seems larger than one high in the sky. *And there have been any number
of incidents which demonstrate beyond all reasonable doubt that people
will believe almost any old tosh - and judge what they see and hear on
this basis - if they do not know or cannot understand the truth.

--
- Yokel -

Yokel posts via a spam-trap account which is not read.


The moon is always closer to the earth than average at new moon
and full moon, slightly more so in the latter case, so the closest
perigees always occur near full moon. This current one is nothing
very special - the moon was closer in 1992, 1993 and 2008 by a few
tens of km. I have never been able to look at the moon and discern
whether it is at apogee or perigee even though the size varies by
±7%. The altitude illusion easily swamps any such change. The moon
is actually measurably *larger* when high in the sky compared with
when on the horizon by a maximum of about 1.6% in these latitudes
because you are then closer to it by a large fraction of the earth's
radius, which is about 1/60th of the distance to the moon.
This full moon, although bright because of the closeness, is not
especially so, the moon being 5.00 degrees from the ecliptic (near the
maximum) and the increase in brightness at full phase is surprisingly
large due to the direct reflection effect.

Tudor Hughes, Warlingham, Surrey.


Dawlish March 20th 11 08:09 AM

Not so super 'super' moon...
 
On Mar 20, 4:56*am, Tudor Hughes wrote:
On Mar 19, 10:12*pm, Yokel wrote:







There are both real and psychological effects.


The moon's orbit is distinctly elliptical, so the moon's distance varies
significantly as it goes round. *This can be shown by looking at solar
eclipses, which vary from the moon being large enough to completely
cover the sun for about 7 minutes at any given point, to "annular"
eclipses when even at mid-eclipse a ring of sunlight is left around the
moon's disk. *Of course, the moon passes through "perigee" every month,
but it is only really noticeable when it occurs at full moon and our
satellite is displayed in full sunlit glory.


The shape of the moon's orbit also varies slightly due to gravitational
effects from the changing geometry of earth, moon and sun. *This has
resulted in the orbit currently becoming slightly more elliptical than
normal, hence the slightly closer approach highlighted for tonight. *The
earth's orbit and angle of the rotation axis also change in this way
over long timescales - these variations affect the distribution of solar
heating over the globe and a gentleman called Milankovitch showed how,
together with "feedback" effects, these variations could partly explain
the pattern of ice ages and interglacials.


The very real psychological effect is that the brain uses various cues
to estimate the size of objects very far away. *Experiments with pairs
of drawings have shown that the brain can be "fooled" by a surprising
amount *- an object seen close to the horizon providing a "scale" for it
seems larger than one high in the sky. *And there have been any number
of incidents which demonstrate beyond all reasonable doubt that people
will believe almost any old tosh - and judge what they see and hear on
this basis - if they do not know or cannot understand the truth.


--
- Yokel -


Yokel posts via a spam-trap account which is not read.


* * The moon is always closer to the earth than average at new moon
and full moon, slightly more so in the latter case, so the closest
perigees always occur near full moon. *This current one is nothing
very special - the moon was closer in 1992, 1993 and 2008 by a few
tens of km. *I have never been able to look at the moon and discern
whether it is at apogee or perigee even though the size varies by
±7%. *The altitude illusion easily swamps any such change. *The moon
is actually measurably *larger* when high in the sky compared with
when on the horizon by a maximum of about 1.6% in these latitudes
because you are then closer to it by a large fraction of the earth's
radius, which is about 1/60th of the distance to the moon.
* * *This full moon, although bright because of the closeness, is not
especially so, the moon being 5.00 degrees from the ecliptic (near the
maximum) and the increase in brightness at full phase is surprisingly
large due to the direct reflection effect.

Tudor Hughes, Warlingham, Surrey.- Hide quoted text -

- Show quoted text -


Thanks both of you. Interesting. we had a veil of high cloud at 9pm
when I looked, so the size was hard to judge. There was a spectacular
halo though.

Martin Brown March 20th 11 09:10 AM

Not so super 'super' moon...
 
On 19/03/2011 19:29, David Allan wrote:
Now I don't know about anyone else, but the so-called 'super moon' didn't
look any bigger than loads of other moon rises I've witnessed.
The full-moon at moonrise often appears much bigger (and so does the sun at
sunrise).
OK, so it's also supposed to be closer to us in its orbit to boot, but I
reckon that extra closeness is not THAT close that you're going to be able
to visually notice the difference.
Eye-catcing it was... but no more eye-catching than many another moonrise at
full moon.


If you were measuring it or trying to take a photo with a decent large
lens then the difference would be obvious. The orbital eccentricity is
about 0.05 so the moons apparent diameter last night at perigee was 10%
bigger than it would be if it occurred at the furthest point apogee.

That you cannot easily spot the difference by eye says a lot about the
limitations of the claim that seeing is believing. Once you have a
camera, micrometer or other measuring instrument the change is obvious.

Regards,
Martin Brown

Roger Smith March 20th 11 09:40 AM

Not so super 'super' moon...
 

"Tudor Hughes" wrote in message
...
On Mar 19, 10:12 pm, Yokel wrote:

The moon is always closer to the earth than average at new moon

and full moon, slightly more so in the latter case,

(snip)

Tudor Hughes, Warlingham, Surrey.

..........................
Tudor

I assume you mean that the average earth-moon distance at new and
(especially) full moons is greater than the overall average, but do you have
chapter and verse for this? I am not challenging the statement, but I had
never heard it before and I am curious.

Regards, Roger




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