Comments

You must log in or register to comment.

triffid_hunter t1_j4qz5st wrote

> What if a planet has it's magnetic north pointing towards it's star ?

Like Uranus? It's magnetic north only faces the Sun once per year though, because that's how orbits and rotation works…

> We are used to know that the Earth's north is aligned with the sun's north

It really doesn't :P

19

yayforfood1 t1_j4r0rfl wrote

magnetic north tends to align approximately with the rotation of the planet so yes, it's possible, but it would only be aligned twice a year like Uranus. if a magnetic pole is pointing towards the star, it lets a lot of solar wind into the atmosphere.

8

szypty t1_j4r4c02 wrote

Hmm, unless it was also tidally locked maybe?

2

yayforfood1 t1_j4r5594 wrote

no, if it was tidally locked, the axis of rotation would be where we expect the north/south poles to be. u can't rotate on 2 axes at once, and as far as I know, tidal forces wouldn't be strong enough to precess the axis once a year like that. something something rotational inertia (to be clear, I'm not a physicist, I just have spent way too much time learning about space)

3

Future_Professor738 t1_j4qya0x wrote

There is something close to what you’re describing. Uranus has a tilt of 97.7 degrees, so the sun is close to being its North (or South) Star. The Earth’s tilt also means it isn’t aligned to the Sun’s north-south axis. This is what leads to seasons.

3

Oxey405 OP t1_j4qz0nw wrote

Thanks for this answer ! I guess this is possible but the inclinaison never falls on a perfectly round angle

0

VertigoOne1 t1_j4r7dxe wrote

The magnetic side of things is completely arbitrary on internal inner/outer core/mantle interactions and it can even flip, disappear or be stable. The rotation of the core is obviously in the same inclination but the field from it is far from “stable”. Currently north is somewhere over northern canada i think. The physical inclination of a planet is most likely due to material accretion, and then large planetoid collisions, like a mars sized body wacking earth from an inclined orbit, which imparts that inclination (part of it) to a young earth. These inclined impacts happen due to gravitational interactions with other bodies which throw them in any which direction the masses worked out. Chaotic to say the least. That most planets except weirdo uranus ended up with sensible/neat inclinations just indicate they were mostly in orbits and that the disc formed fairly flat. Any significant planetoids in way out orbits likely ejected themselves due to being too weird to become likely impactors (3D space, 2D racetrack). That being said, venus is rotating completely the wrong way around so it wasn’t all neat and tidy.

1

ah-tzib-of-alaska t1_j4r4w62 wrote

like if it were tidally locked? so likely a dwarf star?

1

space-ModTeam t1_j4r97mv wrote

Hello u/Oxey405, your submission "What if a planet has it's magnetic north pointing towards it's star ?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

1

vlanmusk t1_j4r9gbu wrote

Would gravitational forces slowly "correct" it's axis so that they are closer to parallel?

1