Spam email from some trivia website: “Which Two Planets in Our Solar System Spin Clockwise?”
My mind: Ermm, clocks are circles, planets are spheres. We viewing this planet from the south pole or the north pole?
Does “planet spinning clockwise” conjure up a clear image for you, or does it hit you as it did me, as a meaningless construct?
I would interpret it as viewing from the top (N pole), but in the grand
scheme of things it is pretty much a meaningless construct.
But which is the top (or north), and why?
I would think of it as being viewed from above.
In the case of a planet, it would be viewing from the north pole. Maybe that’s my northern-hemisphere living bias showing Apologies to antipodean board members.
We make assumptions about what is ‘up’ and ‘down’ in our solar system relative to the axis of the sun by assuming it has a north pole on it’s axis, co-oriented with the north pole of the earth, and when viewed from the plane of the ecliptic the planets and sun appear to be spinning one direction or the other relative to each other that can be called clockwise or counter-clockwise. But it’s all relative motion based on assumptions. I assume the earth spins counter-clockwise based on the usual conventions.
Agree with this, and I would look at all the planets from the top down, the top being above the plane of the ecliptic from Earth’s north pole.
I always thought a neat novelty item to have would be a globe of the earth with the south pole on top and all the text upside-down.
It’s the one from where it looks like it’s spinning clockwise!
Yup. ‘Top’ and ‘above’ are also assumptions based on the earth’s and/or sun’s axis having a north pole that we consider to be their tops. Without those assumptions it gets really complicated.
I know that it’s meaningless, but I also know that what they intended was “as viewed from Solar North”.
Here you go.
I’ll argue “meaningless” is much too strong a term. IMO …
The OP’s cited sentence is clearly ambiguous. That doesn’t make it meaningless. It just means some additional context must be applied to understand it. No different than saying “On Main Street, the Walmart will be on your left”. That assumes e.g. you’re coming from one direction, not the opposite direction. But depending on who’s talking to who, one of those directions is far more plausible than the other.
You already have the context that you understand English words. Absent that, its just gibberish. And you have the context that in colloquial speech, “north” and “up” are loosely equated. And that humans generally prefer to look down on things, not up at them. In the case of something written on paper, “up” is coming out of the paper towards the observer, while down is through the paper and away from the observer, etc.
If you know anything of the naming and directional conventions of modern astronomy, that completely removes the ambiguity by convention.
So yes, ambiguous. But far from meaningless.
I’ll also quibble with this bit:
The circle/sphere distinction is incorrect. If you look at a conventional analog clock from the back side, the hands move in a counter-clockwise direction. It is only because you assume the context of looking at it from the front that you think you know what the word “clockwise” represents.
Speaking precisely about any rotation involves defining an axis and defining one end of that axis as the special reference one. There is zero difference in that between a spinning disk, a sphere, or even a 4D hypersphere.
But if we’re defining the frame of reference to be solar north , there’s only one planet with a clockwise rotation: Venus.
Seven have a counter-clockwise rotation, and Uranus just keeps rolling along.
Quite right. Which is why astronomers have an extra special convention for Uranus.
Yeah, they have to stretch a point to make it all fit in, but with enough lube, they’re good. Nobody knows what Uranus thinks of this. 
I suppose one could say rotating in the opposite direction that the sun rotates.
Astronomers talk about prograde and retrograde rotation; I don’t think they normally talk about “clockwise” or “anti-clockwise”. The Earth (unlike Venus) is rotating prograde.
I suppose that, grossly speaking, if (by definition? but what about the Southern Hemisphere?) the Sun moves clockwise when viewed from the Earth, the Earth could be said to be rotating counterclockwise? But I do not see the point of this line of reasoning.
How is prograde and retrograde defined, other than by reference to solar north?
I think the Sun also has counter-clockwise rotation, seen from solar north?
Prograde is when the handedness (CW vs CCW) of the body’s rotation about its axis is the same as the handedness of its orbit around whatever it’s orbiting. Implicitly when viewed from the same POV. Retrograde of course is the opposite.
Most orbiting bodies that rotate at all rotate prograde. The same sort of momentum that got them orbiting at all also got them spinning on their axis the same way.
Explaining retrograde rotation usually involved collisions, captures, etc. Something really big had to have happened to Venus to have it do what it does.
Solar north is defined as the direction from which the Sun has counterclockwise rotation. Just like Earthly north is defined as the direction from which Earth has counterclockwise rotation.
And Uranus is close to sideways, but it’s still slightly off a perfect 90º angle. And the direction in which its off is the retrograde direction.
Yes; at least in this Solar system and for major planets, I think there is no confusion that, looking down on the Solar system from Solar north (i.e. Earth’s north, we all know which half of the universe we are talking about) prograde motion is counterclockwise.
It’s orbiting prograde but is rotating retrograde.