Celestia Forums

Is there any big different?

Why don't you go and see?

Yes, indeed. Go to Mars in Celestia and look at the sky, notice any change?

In truth (and even in Celestia!) the stars are extremely far away. They are so far that moving merely from Earth to Mars, they all look to be about the same. To notice a difference, you've got to go really far! as in... light years!

The only difference is that Mars has a different north pole star to Earth. You can use Celestia to see which one it is; in fact the pole falls halfway between mu Cephei and Deneb. Otherwise the stars are exactly the same.

Another difference is the position of the Martian ecliptic.

bdm wrote:Another difference is the position of the Martian ecliptic.

I think, though I'm not sure, that's what eburacum45 was getting at.

eburacum45 wrote:...Mars has a different north pole star to Earth..."

Hungry4info wrote:

bdm wrote:Another difference is the position of the Martian ecliptic.

I think, though I'm not sure, that's what eburacum45 was getting at.

eburacum45 wrote:...Mars has a different north pole star to Earth..."

It's not exactly the same. See:

(1) The position of the Martian ecliptic depends on Mars's orbital plane

and

(2) the Martian pole star depends on the orientation of the Mars's rotation axis.

(3) The angle between the equatorial plane and the ecliptical plane depends on both the orbital plane and the rotation axis.

Andy

Ah, yes, I see. Thank-you for the correction.

Hummm *envisioning*... terraformed Mars... sailing upon one of it's oceans, navigating by the stars.

South pole star on Mars is Kappa Velorum, which is rather brighter than Earth's south pole star (Sigma Octantis), though at about 2 degrees off the pole, isn't particularly accurate.

chaos syndrome wrote:South pole star on Mars is Kappa Velorum...

That's interesting. With the Martian lowlands (and thus oceans) being concentrated in the northern hemisphere, I'm afraid a south-pole-star wouldn't help a whole lot when it comes to sailing.

But if you're sailing the Hellas Inland Sea or something, it might be useful...

chaos syndrome wrote:But if you're sailing the Hellas Inland Sea or something, it might be useful...

I'll keep that in mind next time I visit the area

Mars will have a different North Star and South Star to Earth.

Mars will have a slightly different ecliptic inclined at an angle of about 2 degrees to Earth's ecliptic.

The constellations will be much the same, except the stellar parallax over the course of a Martian year will be about 52% greater.

bdm wrote:...the stellar parallax over the course of a Martian year will be about 52% greater.

And with the wider baseline, the parallax measurements would be more accurate.