One of our more brilliant members should know the answer to this. Is our solar system's rotational axis aligned with that of the whole galaxy? Or is it skewed at some angle or does it wobble?

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

Bob -- This is a fast, and incomplete reply. The Earth's axis is skewed,
and it wobbles. This is nothing new, to you. As for the solar system's
axis, w/respect to the plane of the Milky Way -- I don't know. Will try
Googling it.

There is a good book on a planet's axis, and more, on a planet without a
sufficiently-large moon to provide relative stability, "What if the Earth
Had Two Moons?", by Nicholas Carr.

Per a Google search, Bob:

"Newton Ask a Scientist", Argonne National Laboratory/US Dept of Energy Office
of Science

Question:

Is the disk of our solar system coplanar with the disk of the Milky Way?

Answer (Only one, of two entries, listed here):

The plane of the Solar System is called the ecliptic. The plane that stars
appear to rotate in, as seen from a point on the Earth, is called the Celestial
equator. The angle between the ecliptic and the Celestial equator is, of
course, equal to the angle between the Earth's rotation axis and the Solar
System's axis, 23.5 degrees. The Galactic Equator is tilted about 63.5 degrees
from the Celestial equator, in the opposite direction of the ecliptic. So, why
aren't all these rotations coplanar? Like one might expect from Conservation
of Angular Momentum? We think that when the Solar System was just a rotating,
collapsing cloud of gas and dust, a passing star came close enough to change the axis of rotation.

Hope this proves enlightening. I'm no astronomer; perhaps, someone such as
Tullio, could say it all a little better.

Bob -- This is a fast, and incomplete reply. The Earth's axis is skewed,
and it wobbles. This is nothing new, to you. As for the solar system's
axis, w/respect to the plane of the Milky Way -- I don't know. Will try
Googling it.

There is a good book on a planet's axis, and more, on a planet without a
sufficiently-large moon to provide relative stability, "What if the Earth
Had Two Moons?", by Nicholas Carr.

I knew the earth was tilted and wobbles but uncertain about the entire solar system.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

A good question. I don't know if the ecliptic wobbles, or not. It seems that
it should, over time, due to the presence of passing stars/galactic gravity
variations (assuming that there any variations).

As there is stuff in orbit of the sun, the center of mass of the system is shifting, that will create nutation. Precession is a given as there are other stars in the galaxy to gravitationally upset the system, and of course the sun is in motion around the galaxy. You could ask the same of the solar system's orbit in the galaxy, same answers. Also same answers about the galaxy itself.

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All spinning things can and usually do have precession, that's the scientific term for wobble.

The spinning force has to be exactly 90° to the vertical axis for there not to be any precession and there has to be no outside influences, like gravitation pull from passing object.

Earth's precession cycle takes 26,000 years.

This is a rather complex question and right now I do not have these things in front of me.

But I did look at this subject in the past.

Since the earth is subject to both precession, nutation, etc., it would be a better idea of looking at the sun instead.

We happen to be defining the difference between "north" and "south" either because our way of looking at the earth itself, or possibly making a difference between positive and negative charges like those on a magnet.

Also, we would like to be making a difference between "up" and "down", or "top" vs. "bottom".

In the middle of the day, we are not able to see three-dimensional space, but at rare times, when the moon is rising from the horizon, you may be able to notice the stars in the same field if they happen to be bright enough.

Occasionally you may be in for a surprise. At least it happened to me not too long ago, when viewing such a rising moon through binoculars.

Next, it becomes a little more difficult.

We know that most planets in the solar system follows the ecliptic.

But that is because we are observing these planets by means of kind of a two-dimensional view.

With that meaning either you or me at one end and the planet, like Mars or Jupiter at the other end.

Think about rotational direction as being either clock-wise or anti-clockwise. Is that because we are viewing such a direction from either top, bottom, up, or down?

It should be noted that the planet Uranus is having a tilt of its rotational axis some 98 degrees from its angle of direction compared with its roughly circular orbit around the sun.

Meaning that it is in fact tumbling through space.

Its day is roughly 15 hours (neeeds checking), while it takes some 84 years to complete an orbit around the sun.

At the same time the sun, together with the rest of the planets, is moving through space because of the sun being a member of the Milky Way, which is known to be having a rotational period of some 220-225 million years.

Which is hard for most people to catch and therefore is not being noticed at all.

A more important fact is that position in the sky on the ecliptic for summer sunstice and the opposite for winter sunstice is not that far away from the similar positions locating the center of the Milky Way in Sagittarius and the border between Taurus and Gemini for the Milky Way anti-centre.

I do not have the manuals in front of me, so this becomes only a rough description.

If that was not the answer to your question, you rather have to ask an astronomer instead.

My question was related to this thought. If most star/planet systems are oriented in generally the same plane as the spin of the galaxy then we should be able to see/detect a lot of planets as they circle their star(s). That is assuming any given star is observed long enough for the effect of a planet crossing it's star to repeat itself. Someone would have to watch our sun for a long time, almost 12 years, to detect Jupiter completing an orbit. That, for us, is a long time to watch just one star.

So far the planet hunters have been finding stars with planets that complete an orbit in a few days to a few weeks which in my mind makes them unlikely candidates for finding life or being suitable for colonization. So how will they detect stars with planets that have orbital periods similar to ours.

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Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.

Just read: "Better Than Earth", by Rene' Heller, Scientific American,
pp. 32-39.