GPS
We haven't put GPS satellites around Mars quite yet. I'm guessing that won't happen until it gets terraformed.
That being said, how many satellites are orbiting Mars right now that could be used to help determine position?
Compasses don't work on Mars, so how do you navigate?
31–40 of 87 posts
Re: Compasses don't work on Mars, so how do you navigate?
#32Earlier quoted context omitted.
On the hot side as long as you are not exactly on the equator the sun acts as a fixed direction and you can use that. ISTM this would work on the equator too?
On the equator the sun could be directly overhead - so you have no idea what any directions are, the sun is equally far from all horizons. (Remember the sun does not move on mercury.) If you are on the equator, but not directly under the sun then you can figure things out. I guess I should have said equator on the central meridian. Edit: I was under the mistaken assumption that Mercury is tidally locked. So it would…
The sun does move on Mercury. Mercury is not tidally locked- it has a 3:2 spin-orbit resonance. I.e., it rotates 3 times for every two times it goes around the sun. This means that the two sides of the planet alternate facing the sun at perihelion.
Re: Compasses don't work on Mars, so how do you navigate?
#33Does having "no strong magnetic field" mean no Ionosphere and thus no Shortwave Radio?
Re: Compasses don't work on Mars, so how do you navigate?
#34I am surprised that no one has yet mentioned the Gyrocompass: https://en.wikipedia.org/wiki/Gyrocompass
The post mentions manually-set directional gyroscopes, but gyrocompasses are a step ahead of that; on any sufficiently-quickly-rotating planet, a gyrocompass will point you towards the geographic poles by noting the axis of precession of a gyroscope with arbitrary orientation. That's even better than a magnetic compass on Earth, since the magnetic poles do not line up exactly with the geographic poles, and the magnetic is non-uniform anyway (which is why navigational charts include notations of the magnetic deviation in different areas).
Re: Compasses don't work on Mars, so how do you navigate?
#35Celestial navigation plus accurate clocks. I'd think this would be especially good on a planet without clouds (as long as your planet rotates fast enough, so I guess Mercury is out). Anyone know if Mars has any polar stars? https://en.wikipedia.org/wiki/Celestial_navigation
Doesn't Mars have clouds, though?
Re: Compasses don't work on Mars, so how do you navigate?
#36Earlier quoted context omitted.
That's still like a couple of degrees (4 full moons) away so not sure how accurate it would be. Still the thought of seeing literally the same stars on an alien world is blowing my mind. Just imagine the same sky, but different planet... wow
I wonder if "giant head" enhanced depth perception works across planets? https://xkcd.com/941/
Just a nitpick, but how could one see the tops of clouds when the two cameras are only negligibly above ground level?
Re: Compasses don't work on Mars, so how do you navigate?
#37Earlier quoted context omitted.
That's still like a couple of degrees (4 full moons) away so not sure how accurate it would be. Still the thought of seeing literally the same stars on an alien world is blowing my mind. Just imagine the same sky, but different planet... wow
I wonder if "giant head" enhanced depth perception works across planets? https://xkcd.com/941/
Stellar parallax is virtually unnoticeable even when the Earth is on opposite sides of the Sun (~300M km apart), so I don't think the stars would look much differet even if you doubled or tripled that distance.
Objects inside of our own solar system, on the other hand, would be really interesting to look at through such a setup.
Re: Compasses don't work on Mars, so how do you navigate?
#38GPS
We haven't put GPS satellites around Mars quite yet. I'm guessing that won't happen until it gets terraformed.
I think terraformed is long after we'd want GPS. Once we have any sort of Martian colony (which is usually a prerequisite for terraforming, not the other way around) and the ability to build rockets and fuel from Martian resources, it should be straightforward for Martians to set up a GPS network of their own (easier than Earth, probably, due to the lower gravity and thinner atmosphere).
Re: Compasses don't work on Mars, so how do you navigate?
#39Earlier quoted context omitted.
I wonder if "giant head" enhanced depth perception works across planets? https://xkcd.com/941/
Fun link. I was planning on similar setup using a couple of remote linked Celestron C8s separated by 5 miles to observe thunderhead cloud formation in SW Florida. Average natural IPD is around 64mm so it should be interesting to see what the occipital lobe does when this is expanded to over 8km. (IPD = InterPupillary Distance; eyeball separation)
IPD?
Re: Compasses don't work on Mars, so how do you navigate?
#40Earlier quoted context omitted.
We haven't put GPS satellites around Mars quite yet. I'm guessing that won't happen until it gets terraformed.
It could be set up years ahead of any significant ground presence, at a fairly small cost.
Existing GPS satellites orient themselves by ground stations, so we'd need at least some ground presence. Said presence doesn't have to be manned, though.