Terminology for motion in the solar system, ecliptic maybe?

In summary, the terminology for motion in the solar system includes key concepts such as the ecliptic, which is the plane of Earth's orbit around the Sun. This plane serves as a reference for understanding the positions and movements of celestial bodies. Important terms also encompass heliocentric (Sun-centered) and geocentric (Earth-centered) models, as well as concepts like retrograde motion, which describes the apparent backward movement of planets. Understanding these terms is essential for studying the dynamics of the solar system and the interactions between various celestial objects.
  • #1
Albertgauss
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TL;DR Summary
What is the terminology for moving through the solar system?
Just looking for terminology here.

If an object moves through the solar system, what is the simplest terminology that relates to how the object moves through the solar system?

What are the words for if an object moves

towards the sun (radially inwards)
away from the sun (radially outwards)
counterclockwise with the Earth's orbit (prograde?) (as seen from north hemisphere of Earth, looking south)
clockwise with respect to the Earth's orbit (retrograde?) (as seen from north hemisphere of Earth, looking south)
Out of the solar system plane
Towards the solar system plane

Are there any simpler terms than "North Ecliptic Pole" and "South Ecliptic Pole"?

I could not find anything obvious on the internet but are there any stars that remain relatively fixed over a human lifetime above the north pole of the sun? South pole of the sun?
 
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  • #2
Are you looking for industry terms or just convenient terms?
'cuz you seem to have already got some pretty good convenience terms there.

Some quick Googly-eying turns up this:

"The North Pole of the sun points towards the constellation Draco. There is no bright star close to the North Pole of the Sun. The closest fairly bright star is Delta Draco, "Altais". A magnitude 3 star."
https://astronomy.stackexchange.com...star-is-directly-north-of-the-suns-north-pole
 
  • #3
Albertgauss said:
TL;DR Summary: What is the terminology for moving through the solar system?

Just looking for terminology here.
"Trajectory?"
 
  • #4
DaveC426913 said:
Are you looking for industry terms or just convenient terms?
'cuz you seem to have already got some pretty good convenience terms there.

Whichever is simplest. I feel like there's got to be an easier/simpler way to say "moving radially towards the sun" or "out of the ecliptic plane" for instance. What would someone at NASA say if they were trying to move a satellite around the solar system?

DaveC426913 said:
"The North Pole of the sun points towards the constellation Draco. There is no bright star close to the North Pole of the Sun. The closest fairly bright star is Delta Draco, "Altais". A magnitude 3 star."
Yes, that looks to be the case. That looks to be why I couldn't find a star over the north pole of the sun.

Bystander said:
"Trajectory?"

Too vague.

Local motion on Earth could be described completely as: "up, down, left, right, out, in." I realize from this post that analogous terminology for moving in the solar system may not exist, but maybe someone will have some terminology I could not find easily on the internet.
 
  • #5
  • #6
pbuk said:
Up (or North), down (or South), in, out, clockwise (or West), anti-clockwise (or East).
That works! So simple I missed it.
 
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  • #7
Albertgauss said:
...there's got to be an easier/simpler way to say "moving radially towards the sun"...
sunward.
 
  • #8
pbuk said:
Up (or North), down (or South), in, out, clockwise (or West), anti-clockwise (or East).
Prograde and retrograde are more objective and more useful.
 
  • #9
DaveC426913 said:
Prograde and retrograde are more objective and more useful.
You may find them more useful but you can hardly say that they are more objective: prograde with respect to what?

Personally I can never remember which way the Earth goes round the Sun, but I know that once we have defined 'North' (or 'up') for an orbital system, clockwise is easy to find.

For more technical insight (reference frames used by NASA's JPL) see https://ssd.jpl.nasa.gov/horizons/manual.html#frames
 
  • #10
pbuk said:
You may find them more useful but you can hardly say that they are more objective: prograde with respect to what?
All the planets, minor planets and asteroids. And the sun's revolution.
In short: with respect virtually everything.

pbuk said:
Personally I can never remember which way the Earth goes round the Sun,
You, pbuk, do know. It goes prograde, by definition.

See?

What you don't have to remember is whether that's clockwise or counterclockwise, because who cares?


See it's not about knowing some external-to-the-solar-system direction. This about moving within the solar system. What is going to be very important is the direction relative to what the things you are amongst are doing.

👎
Captain: "Helmsman, we're about to cross Mars' orbit. Which way are we orbiting?"
Pilot pbuk: "Clockwise, sir!"
Captain: "Great. Er ... remind me again which direction Mars is orbiting?"
Pilot pbuk: "Counterclockwise, sir!"
Captain: "Great. Opposite to Mars. It'll whiz past us long before we cross."

👍
Captain: "Helmsman, we're about to cross Mars' orbit. Which way are we orbiting?"
Pilot Dave: "Retrograde, sir!"
Captain: "Great. Opposite to Mars. It'll whiz past us long before we cross."
 
  • #11
Note that prograde and retrograde are used in reference to something's orbit. If you're talking about which direction something is going in relation to the Sun, or a coordinate system centered on the Sun, then you can't use those.
 
  • #12
Drakkith said:
Note that prograde and retrograde are used in reference to something's orbit. If you're talking about which direction something is going in relation to the Sun, or a coordinate system centered on the Sun, then you can't use those.
🤔 I'm not sure what you are objecting to.

"A planet has a prograde orbit or rotation if the sense of rotation is the same as the general sense of rotation of the Solar System."
- Oxford Reference

"[Pro]grade motion in astronomy is, in general, orbital or rotational motion of an object in the direction [the same as] the rotation of its primary, that is, the central object.
...
In the Solar System, the orbits around the Sun of all planets and most other objects, except many comets, are prograde. They orbit around the Sun in the same direction as the sun rotates about its axis..."

- Wiki


This seems to cover what I'm getting at. Is it possible I'm misinterpreting the gist of your post?
 
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  • #13
DaveC426913 said:
In short: with respect [to] virtually everything.

DaveC426913 said:
What is going to be very important is the direction relative to what the things you are amongst are doing.
I think you are missing my point: when a definition is "with respect to" or "relative to" something then it is subjective, not objective.
 
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  • #14
pbuk said:
I think you are missing my point: when a definition is "with respect to" or "relative to" something then it is subjective, not objective.
If it is not relative to something then by definition you can not describe its motion/trajectory!

For instance a thrown object in a gravity field could be seen as a parabola if seen from a point perpendicular to its plane, or as a straight line if seen from a point in its plane of motion.

Each description is relative to the observer, you, and totally accurate.

p.s. isn't philosophy banned here?
 

FAQ: Terminology for motion in the solar system, ecliptic maybe?

What is the ecliptic?

The ecliptic is the apparent path that the Sun traces out in the sky over the course of a year, as seen from Earth. It represents the plane of Earth's orbit around the Sun and is used as a reference for the positions of other celestial bodies in the solar system.

How does the ecliptic relate to the zodiac?

The zodiac is a band of the sky that extends about 8 degrees on either side of the ecliptic. It is divided into twelve equal parts, each associated with a constellation. The Sun, Moon, and planets all move through this band, making the zodiac an important concept in both astronomy and astrology.

What is the difference between the ecliptic and the celestial equator?

The celestial equator is the projection of Earth's equator onto the celestial sphere, while the ecliptic is the plane of Earth's orbit around the Sun. The two are inclined to each other by about 23.5 degrees, which is the tilt of Earth's rotational axis. The points where they intersect are known as the equinoxes.

What are the nodes of the Moon's orbit?

The nodes of the Moon's orbit are the points where the Moon's path crosses the ecliptic. The ascending node is where the Moon moves from south to north of the ecliptic, and the descending node is where it moves from north to south. These nodes are important for predicting eclipses.

What is an ecliptic coordinate system?

The ecliptic coordinate system is a celestial coordinate system that uses the ecliptic plane as the primary reference. It is often used in astronomy to describe the positions of objects in the solar system. The two main components are ecliptic longitude and ecliptic latitude, analogous to longitude and latitude on Earth.

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