4 ms·

North, South, East, and West?

ragmondo 14y ago
and what's your definition of those on another planet that doesn't have a magnetic pole ? Is the "North" the "top" of the rotation - which way is the top ?? (here's a link that shows what a compass would do on the surface of Mars : http://mgs-mager.gsfc.nasa.gov/publications/grl_28_connerney/grl_28_connerney_fig1.html http://mgs-mager.gsfc.nasa.gov/publications/grl_28_connerney... )
- biesnecker 14y ago
  The rotational pole, I would imagine. Just as the geographic poles are sometimes referenced on Earth.
- sp332 14y ago
  You know Earth's magnetic poles don't match up with its rotational poles right? They're kinda close, but the magnetic poles wander. Even though Mars (oddly) doesn't have strong magnetic poles, that doesn't mean it doesn't have poles. As for which one is north, we just pick a direction of the solar system to be "north". http://en.wikipedia.org/wiki/Poles_of_astronomical_bodies http://en.wikipedia.org/wiki/Poles_of_astronomical_bodies
  - rubidium 14y ago
    I would guess that we now name the "north pole" on any planet that which your thumb points when doing the right hand rule with the rotation of the planet... but I'm not sure.
    - sp332 14y ago
      That's used for moons and dwarf planets etc. But in this solar system, we actually have a designated hemisphere that is "north" for planets. It's explained in that link I posted.
- DougBTX 14y ago
  The orbital axis of all the planets in our solar system are roughly parallel (within 10 degrees, Mars is just under 2 degrees off ours), so it would be fair to pick a north pole at the same "end" as ours. http://en.wikipedia.org/wiki/Orbital_inclination http://en.wikipedia.org/wiki/Orbital_inclination
  - wkdown 14y ago
    Fun fact: Uranus is at 97+ degrees, making it almost perpendicular to the other planets axis http://en.wikipedia.org/wiki/Uranus#Axial_tilt http://en.wikipedia.org/wiki/Uranus#Axial_tilt
    - DougBTX 14y ago
      Hm, guess that means I don't understand the article I linked to.
      - timmaxw 14y ago
        I think you were confusing orbital inclination with axial tilt. http://en.wikipedia.org/wiki/Axial_tilt http://en.wikipedia.org/wiki/Axial_tilt
      - bmunro 14y ago
        The article you linked to describes the angle of plane of the orbit - the circle it makes around the sun. These vary by only a small amount. The axial tilt is different. It is basically how far the axis through the poles of a planet is tilted compared to the plane of its orbit. This is what you were thinking of initially - it can very a lot.
        wkdown 14y ago
        Pluto, while no longer a planet, as an inclined orbital tilt as well. It will also occasionally come inside the orbit of Neptune. http://en.wikipedia.org/wiki/Pluto#Orbit_and_rotation http://en.wikipedia.org/wiki/Pluto#Orbit_and_rotation

and what's your definition of those on another planet that doesn't have a magnetic pole ? Is the "North" the "top" of the rotation - which way is the top ?? (here's a link that shows what a compass would do on the surface of Mars : http://mgs-mager.gsfc.nasa.gov/publications/grl_28_connerney/grl_28_connerney_fig1.html http://mgs-mager.gsfc.nasa.gov/publications/grl_28_connerney... )

biesnecker 14y ago
The rotational pole, I would imagine. Just as the geographic poles are sometimes referenced on Earth.
sp332 14y ago
You know Earth's magnetic poles don't match up with its rotational poles right? They're kinda close, but the magnetic poles wander. Even though Mars (oddly) doesn't have strong magnetic poles, that doesn't mean it doesn't have poles. As for which one is north, we just pick a direction of the solar system to be "north". http://en.wikipedia.org/wiki/Poles_of_astronomical_bodies http://en.wikipedia.org/wiki/Poles_of_astronomical_bodies
- rubidium 14y ago
  I would guess that we now name the "north pole" on any planet that which your thumb points when doing the right hand rule with the rotation of the planet... but I'm not sure.
  - sp332 14y ago
    That's used for moons and dwarf planets etc. But in this solar system, we actually have a designated hemisphere that is "north" for planets. It's explained in that link I posted.
DougBTX 14y ago
The orbital axis of all the planets in our solar system are roughly parallel (within 10 degrees, Mars is just under 2 degrees off ours), so it would be fair to pick a north pole at the same "end" as ours. http://en.wikipedia.org/wiki/Orbital_inclination http://en.wikipedia.org/wiki/Orbital_inclination
- wkdown 14y ago
  Fun fact: Uranus is at 97+ degrees, making it almost perpendicular to the other planets axis http://en.wikipedia.org/wiki/Uranus#Axial_tilt http://en.wikipedia.org/wiki/Uranus#Axial_tilt
  - DougBTX 14y ago
    Hm, guess that means I don't understand the article I linked to.
    - timmaxw 14y ago
      I think you were confusing orbital inclination with axial tilt. http://en.wikipedia.org/wiki/Axial_tilt http://en.wikipedia.org/wiki/Axial_tilt
    - bmunro 14y ago
      The article you linked to describes the angle of plane of the orbit - the circle it makes around the sun. These vary by only a small amount. The axial tilt is different. It is basically how far the axis through the poles of a planet is tilted compared to the plane of its orbit. This is what you were thinking of initially - it can very a lot.
      - wkdown 14y ago
        Pluto, while no longer a planet, as an inclined orbital tilt as well. It will also occasionally come inside the orbit of Neptune. http://en.wikipedia.org/wiki/Pluto#Orbit_and_rotation http://en.wikipedia.org/wiki/Pluto#Orbit_and_rotation