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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Longitude of Greenwich Observatory
From: Frank Reed CT
Date: 2005 Dec 19, 01:50 EST
From: Frank Reed CT
Date: 2005 Dec 19, 01:50 EST
Peter, you wrote: "In the local paper recently came across an assertion that the northern orbital axis of the earth (ie; the North Pole) had been found to have moved some small (less than the five and a half nautical miles cited by Frank) distance 'to the east'." Actually the Greenwich "discrepancy" was only 5.4 arc SECONDS of longitude. But even that is unlikely and probably related to registering the imagery. I would still like to know if that transit instrument at RGO is still the exact zero of longitude. Has anyone on the list turned on a GPS receiver while standing there? But as for the assertion in the article you read, the rotational axis surely could not move five nautical miles without noticeable effects! That's a very large change. Speculating, could it be that the article was talking about recent ice movements up there? --not a change in the axis of rotation, but only a change in the location where the axis pierces the ice. That does move, and changes in the Arctic ice are big news these days. -FER 42.0N 87.7W, or 41.4N 72.1W. www.HistoricalAtlas.com/lunars
