[OT] Astronomical Inquiry (actually another one)

G'day Tom,

> Consider this, the diameter of the Earth's orbit is greater

Mmmm. so this would mean you could use the same 'traditional' means of
navigation (North star, southern cross etc) anywhere in the solar system, yes?

Cheers

Beth

> Beth Fulton wrote:

> G'day Tom,

No, just because the celestial sphere is (relatively) fixed, the inclination
of the planets will vary. Therefore, Polaris will move in an alien sky.

-Mike

G'day Mike

> No, just because the celestial sphere is (relatively) fixed, the

Oops, forgot about that;)

Thanks

Beth

At 10:57 PM -0500 10/13/99, "The thing is, we're not that good. It's
> just that everybody e wrote:

There's more than a few programs out there that will cheerfully draw
you a night sky as seen from anywhere at any time (usually +/- 4000
years from now IIRC). Astronomica for the Mac is one, your Windows mileage may
(will) vary.

> Mmmm. so this would mean you could use the same 'traditional' means

Well, Polaris won't *move*, but where the axis of rotation (and/or
magnetic pole, if any) will be pointing elsewhere. Polaris will still be
findable,
still the end star in the Little Dipper - of course, this presumes you
stay in the same solar system as Earth (or near enough, relative to the other
stars out there; Beth is asking about things in our solar system, not other
ones :).

Mk

"The thing is, we're not that good. It's just that everybody else sucks.
> (a Navy SEALs quote)" wrote:

> >> Mmmm. so this would mean you could use the same 'traditional' means

Actually, I think my statement is correct. From the reference frame of a
person standing on the surface of Earth, Polaris is fixed, all other stars
move in circles around it. From the reference frame of a person standing on
the surface of Mars, Polaris would move through the Martian sky. Therefore,
you could not use "the same 'traditional' means of navigation (North star,
southern cross etc)." To orient yourself on Mars using Polaris as a guide,
you'd have to develop a simple calculator which takes into account time of day
(night) and date. This would be very similar to the "star dials" that can
allow you tell the time, if you know the date, by aligning the stars in
certain constellations with the calculator. Mars almost certainly has a "North
Star," but I couldn't tell you which one.

-Mike

[moving Polaris]
> Actually, I think my statement is correct. From the reference
[...]

Ah, okay, now I understand what you meant. We both basically were saying the
same thing.

> Mars almost certainly has a "North Star," but I couldn't tell you

Without some digging I cna't either.  ;-)

Mk