Re: Polar Shift
From: Morris Jones (mojo_at_devilrock.whiteoaks.com)
Date: 01/14/05
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Date: Fri, 14 Jan 2005 20:26:36 +0000 (UTC)
Jerry Pool <nlpjp@aol.comremove> wrote:
>How much has the Polar Shift caused by the recent 9.0 earthquake affected the
>circa 2000 star charts?
You need to shift all of your object coordinates by one-half of a
millionth of an arcsecond.
Better update your charts ASAP!
While I marvel at the innumeracy of the press and the public during this
current game of urban myth "telephone," let me make a couple of points:
1. The shift is predicted by a numerical model developed by Richard
Gross at JPL. This is not a measurement, it's the prediction of a model.
2. Part of the reason it hasn't been measured is because the model's
predictions are too small to measure with current technology.
Example: The model predicts a speed-up in the Earth's rotation of 2.7
microseconds. The earth's rotational period can't be measured to an
accuracy any better than 20 microseconds.
<http://earthquake.usgs.gov/eqinthenews/2004/usslav/neic_slav_faq.html>
But, you know, just to be on the safe side, I recommend that you buy
replacements for all of your charts and charting software as soon as
possible.
Mojo
-- Morris Jones <*> Monrovia, CA http://www.whiteoaks.com Old Town Astronomers: http://www.otastro.org
- Next message: Mike Reed: "1st Surface Image Released"
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