NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Extra-terrestial celestial navigation
From: Peter Fogg
Date: 2003 Feb 14, 10:08 +1100
From: Peter Fogg
Date: 2003 Feb 14, 10:08 +1100
Peter Fogg wrote: > > While in earth orbit I had imagined that Declination and Sidereal Hour Angle and Distance from Earth could form the 3 axis for a 3 dimensional fix. But what are the references > once you leave the earth behind? I guess the star field remains a (relative) constant, reference to the earth or the sun would be confusing because of their movement? After thinking about this some more it has become clearer, at least in my own mind (funny about that). While in earth orbit simple latitude and longitude coupled with altitude is all that is needed. The problem with celestial navigation away from the earth is that the celestial sphere is predicated with the earth at its centre. And the problem with that is that the earth is spinning on its axis and also orbiting the sun. But a slight shift in definition, to taking the sun as the centre (strictly speaking, the centre of the sun) doesn't make much difference to the celestial sphere (as we understand it) and gives a (relatively) static object as a reference point. So I guess the new equator is the plane on which the planets revolve. So: Dec and SHA remain usable (for lack of an alternative we are still using the first point of Aries as our longitudional reference point) and distance from the sun becomes the 3rd axis. Hhm, I think we still need a north south east west equivilant to designate in which quadrant of the orbital plane we are located. Back to the drawing board. In any case, this system is only useful so long as we remain within our own solar system. Of course, whether the actual method(s) used are similar to this I have no idea.