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The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

A further, non-gravitational effect is that the Solar System is somewhat more likely to be within the "danger zone" of a nearby supernova as it crosses the Galactic midplane. This also is unlikely to have any influence on the rotation and spins of the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -2\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane (derivation here).

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{2\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

High mass stars are generally born and live their short lives within a few tens of pc from the Galactic midplane. Thus this is also the location of most type II (core collapse) supernovae. A nearby supernova (less than a few parsecs) is likely to be quite damaging to the Solar System planets (to their atmospheres, though possibly not to their orbits and certainly not to their rotation and spins). The vertical motion of the Sun is an oscillation with a period of around 70 Myr and a semi-amplitude of around 100 pc. That means that every 35 Myr or so there is a possibility for the Solar System to be in the vicinity of a core-collapse supernova (though you have to factor in spiral arm location too).

The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

A further, non-gravitational effect is that the Solar System is somewhat more likely to be within the "danger zone" of a nearby supernova as it crosses the Galactic midplane. This also is unlikely to have any influence on the rotation and spins of the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -4\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane (derivation here).

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{4\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

High mass stars are generally born and live their short lives within a few tens of pc from the Galactic midplane. Thus this is also the location of most type II (core collapse) supernovae. A nearby supernova (less than a few parsecs) is likely to be quite damaging to the Solar System planets (to their atmospheres, though possibly not to their orbits and certainly not to their rotation and spins). The vertical motion of the Sun is an oscillation with a period of around 70 Myr and a semi-amplitude of around 100 pc. That means that every 35 Myr or so there is a possibility for the Solar System to be in the vicinity of a core-collapse supernova (though you have to factor in spiral arm location too).

The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

A further, non-gravitational effect is that the Solar System is somewhat more likely to be within the "danger zone" of a nearby supernova as it crosses the Galactic midplane. This also is unlikely to have any influence on the rotation and spins of the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -2\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane (derivation here).

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{2\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

High mass stars are generally born and live their short lives within a few tens of pc from the Galactic midplane. Thus this is also the location of most type II (core collapse) supernovae. A nearby (less than a few parsecs) is likely to be quite damaging to the Solar System planets (to their atmospheres, though possibly not to their orbits and certainly not to their rotation and spins). The vertical motion of the Sun is an oscillation with a period of around 70 Myr and a semi-amplitude of around 100 pc. That means that every 35 Myr or so there is a possibility for the Solar System to be in the vicinity of a core-collapse supernova.

The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

A further, non-gravitational effect is that the Solar System is somewhat more likely to be within the "danger zone" of a nearby supernova as it crosses the Galactic midplane. This also is unlikely to have any influence on the rotation and spins of the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -2\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane (derivation here).

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{2\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

High mass stars are generally born and live their short lives within a few tens of pc from the Galactic midplane. Thus this is also the location of most type II (core collapse) supernovae. A nearby supernova (less than a few parsecs) is likely to be quite damaging to the Solar System planets (to their atmospheres, though possibly not to their orbits and certainly not to their rotation and spins). The vertical motion of the Sun is an oscillation with a period of around 70 Myr and a semi-amplitude of around 100 pc. That means that every 35 Myr or so there is a possibility for the Solar System to be in the vicinity of a core-collapse supernova (though you have to factor in spiral arm location too).

The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -2\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane.

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{2\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

The Sun and planets are both pulled together by the gravitational field of the Galaxy. But the differential tidal effects could be felt by planets (or other objects) on orbits of size $\sim 10^5$ au (like putative planet X perhaps, or the outer Oort cloud). These effects could radically alter the orbits of such objects, but not their spins because the tidal forces are tiny on planetary (as opposed to orbital) scales. There would be no effect on the known planets.

A further, non-gravitational effect is that the Solar System is somewhat more likely to be within the "danger zone" of a nearby supernova as it crosses the Galactic midplane. This also is unlikely to have any influence on the rotation and spins of the known planets.

Details

We can use Gauss's law for gravitation to get a rough idea of the gravitational acceleration drawing the Solar System (and everything in it) back towards the Galactic plane. $$g \simeq -2\pi G\rho |z|\ ,$$ where $|z|$ is the distance from the Galactic plane and $\rho$ is the mass density in the plane (derivation here).

However, because this affects the whole Solar System, what really matters for your question is a comparison between the gravitational acceleration on a planet exerted by the Sun and the tidal acceleration caused by the Galactic plane. The latter is given by the gradient of the acceleration given above, multiplied by the separation $r$ between the Sun and a planet. i.e. What matters is the ratio $$\frac{g_{\rm tide}}{g_{\odot}} \simeq \frac{2\pi \rho r^3}{M_{\odot}}\ . $$

Quantitatively, we can express $r$ in au and use $\rho \sim 0.1 M_{\odot}$/pc$^{3}$, so $$\frac{g_{\rm tide}}{g_{\odot}}\simeq 10^{-16}\left(\frac{r}{\rm au}\right)^3 . $$ Thus, for star-planet separations of au to tens of au, the tidal influence of the Galactic plane is negligible. Only planets (or comets, or binary companions, or anything else, since the ratio does not depend on the mass of the orbiting object) with orbits of $\sim 10^5$ au might be affected in any significant way.

This is why, for example, the outer Oort cloud should be pseudo-spherical and any planet X on a very wide orbit may not be in the same plane as the rest of the planets. i.e. The effect is sufficient to change the orbits of such objects, but the torque exerted on small length scales would not be anywhere near enough to affect spin axes or rotation rates.

High mass stars are generally born and live their short lives within a few tens of pc from the Galactic midplane. Thus this is also the location of most type II (core collapse) supernovae. A nearby (less than a few parsecs) is likely to be quite damaging to the Solar System planets (to their atmospheres, though possibly not to their orbits and certainly not to their rotation and spins). The vertical motion of the Sun is an oscillation with a period of around 70 Myr and a semi-amplitude of around 100 pc. That means that every 35 Myr or so there is a possibility for the Solar System to be in the vicinity of a core-collapse supernova.