Re: [Phys-L] Trick photography?

[John Mallinckrodt <ajm@csupomona.edu>]

Yes, but, of course, two weeks later it would be easily visible to a Kiwi 24 hours a day near the celestial south pole.  Near that time its first order apparent motion would be an approximately daily passage around a path spiraling toward and then back away from the celestial pole.  Its apparent angular velocity would be very small, approximately that of stars the same angular distance from the pole.

John Mallinckrodt
Cal Poly Pomona

On 3/3/2014 at 3:34 PM, brian whatcott wrote:

> I don't quite see it - nothing new there! But to the New Zealand videographer, I am supposing that the apparent motion of the Moon would be invisible during the Moon's path through part of the northern celestial hemisphere, once a month?
>
> On 3/3/2014 at 11:04 AM, I wrote:
>
> > There is one other subtle effect related to the inclination of the Moon's orbit to the Earth's equatorial plane.  Because that inclination is only 5 degrees it doesn't produce very noticeable changes in the apparent rate of motion.  But imagine that the inclination were, say, 80 degrees.  In that case the apparent motion of the moon would depend strongly on the orbital phase.  Twice a month the moon would be found only 10 degrees away from a celestial pole and at those times its apparent motion would be very small.