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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Frank Reed
Date: 2022 Apr 24, 11:48 -0700
I looked at the 2004 Deimos transit for a five-minute break just now. This time I assumed the position of Opportunity was as given. I double-checked the martian lat/lon coordinates reported in Stellarium. They are the landing site. While the rover travelled many miles in later years, by early March it had only rolled a few dozen meters. We are given the time to the nearest minute, and assuming the Deimos ephemeris is correct, we can get the actual UT to the nearest five seconds or so by comparing against the image of the transit, even at such low resolution. I get a UT of 03:04:15 on 4 March 2004. That appears to be good to +/-5 seconds.
Fits a general principle: if we have observed details of a transit and accurate UT, we can determine the observer's latitude and longitude. If we have the observed details and known lat and lon, we can determine the Univeral Time.
Frank Reed
