Parallax by Day

On May 25, 1:07 pm, Anthony Ayiomamitis
wrote:
Ernie Wright wrote:
Anthony Ayiomamitis wrote:

http://www.perseus.gr/Astro-Lunar-Parallax.htm

The image scale of the resampled image is around 2.51"/pixel. ;-)

I get an estimate of 438,988 km for the distance of the moon from the
earth when, in fact, it was 395,520 km at the time of photography. In
other words, there is an error of approximately 10%.

I got an estimate of 443,368 km. This is assuming an image scale of
about 3.25"/pixel, which I got from the diameter of the Moon,

557 pixels using the ruler tool in Photoshop CS2
1812" according tohttp://aa.usno.navy.mil/data/docs/diskmap.html

The distance between the two images of Regulus is 337 pixels = 1096".

Moon distance = (Selsey Athens distance / 2) / tan(1096"/2)

I think the error comes from assuming that the Selsey-Athens base of the
triangle is at right angles to the Earth-Moon vector. In general it
won't be. If tilting that line up to make it perpendicular shortens it
to about 2100 km, we get a very accurate estimate.

Thanks for the feedback Ernie. My results vary slightly due to SkyMap
Pro which indicates the moon had an apparent diameter of 1839.34" and
the parallax angle which I estimated to be 1113.6". My estimate as to
the distance also ignored the image scale I specified in an earlier post
which for some reason is not correct and I must check as to the reason(s).

Anyway, a nice exercise. Just ask Oriel.

Anthony.





- Ernie http://home.comcast.net/~erniew- Hide quoted text -

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Here is the orbital motion of the Earth along with Jupiter -

http://antwrp.gsfc.nasa.gov/apod/ima...2000_tezel.gif

The common heliocentric orbit provides the basis for the recognition
of the anomalous motion of Io insofar as the stretching distance
between Earth and Jupiter accounts for the irregular occultation of Io
using finite light speed as conditioning factor.

Of course,you and you buddies refuse to acknowledge orbital
comparisons and use a hypothetical observer on the Sun to account for
the motion of Jupiter -

"For to the earth planetary motions appear sometimes direct,
sometimes stationary, nay, and sometimes retrograde. But from the sun
they are always seen direct, " Newton

As the Mora Luminis of Roemer can only be appreciated by people who
recognise the orbital motion of the Earth,any lesser view such as
parallax is going to highlight that you have no astronomical pedigree
and attaching yourself to Newton's views which exclude orbital
comparisons does just that.

The Roemerian refinement is a wonderful addition to the original
working principles provided by Copernicus and does not involve the
background stars but only the motion of the Earth and that of
Jupiter.If you want to continue to make yourself look foolish then so
be it,at least others are getting the benefit of an education by
exposing yourselves as dull and dour astrologers hellbent on ignoring
orbital motions or rather retaining celestial sphere geometry.

Some of the English who recognise an enormous astronomical version of
Piltdown man in the making can easily become familiar with the orbital
motion of the Earth for the first time and at least try to make the
effort of rectifying matters.As for you,continue taking those nice
pictures of the analemma,do you hear,those nice pictures where a 24
hour clock determines the postion of the Sun !!!!!!.