Hi Philip, You are forgetting that NASA themselves maintain their navigation by the stars. There are direct quotes from Buzz Aldrin, for example, on www.midclyth.supanet.com under "Stars, what stars?" This alone means that the stars have to be fixed in the system that NASA wants us to accept and believe in. You are also confusing the navigation problem with the relative motions that we observe from the World being far easier to mathematically describe within a geocentric framework. If you are in a spaceship heading (so you hope) to the Moon, then you need to know where the Moon is going to be when you get out to that distance - this is not the same as two ships close to each other on the ocean, each having the desire to meet up with each other. You cannot maniputate your position in space in anything like the way you can on the sea. To illustrate, how would your two ships meet up with each other if they could not see each other? They would have to take bearings on a fixed point (well, actually two fixed points) and each calculate where and when they were going to meet. Also, this is not a once off, but a constantly changing calculation, due to their drift on the sea. Similarly, a spacecraft drifts in space and has to be regularly adjusted. The distance of the Moon from the World is not the main issue. You have to know where the Moon is going to be with respect to something that does not move. On the way back, too, you have to know where the World will b e with respect to something that does not move - i.e., the stars in the heliocentric myth. Neville. Philip <joyphil@xxxxxxxxxxx> wrote: Neville said, The reason that the astronauts would have to have referred to the stars is that they would have to constantly take bearings on fixed objects. In the geocentric case, the only thing fixed is the World, which would not facilitate their travelling to the Moon. Such navigational aids are required in both scenarios, because the Moon is a moving target in both (as the World is in a heliocentric system). Neville isn't it a matter of relative motions. NASA could, (someone said that they do) nasa could use the geocentric model for calculations. In the eath moon system, true relative motions are observable. The moon distance and thus its orbit could be calculated by Radar or any radio signal bounced off the moon surface. Knowing these surely they could match a missiles speed to that of the moon, thus avoiding the cataclysm you propose. Isn't it the same as two ships within observation of each other in a flowing sea, and on course navigating to come together without recourse to stars or any other fixed object? Philip. --------------------------------- ALL-NEW Yahoo! Messenger - all new features - even more fun!