Planet Rotation: Questions & Answers

In summary, the rotation of a planet around its star is generally in the same direction as the star's rotation on itself, due to conservation of angular momentum from the initial rotation of the cloud of dust and gas from which they both formed. As for why stars rotate, it is a topic of ongoing research, but it is believed to be a result of their formation process. All stars rotate, although some may rotate faster or slower than others due to various factors.
  • #1
_DJ_british_?
42
0
I've read that a planet's rotation around it's star is in the same direction has the rotation of the star on itself, is that true? If so, why? Does it have something to do with the conservation of angular momentum?. And another question (well, two :P) : why do stars rotate (the outer layer, I mean)(And if it does, the inners?) ? And do all stars rotate? If not, why some do and some don't (four questions, I guess!)?
 
Astronomy news on Phys.org
  • #2
_DJ_british_? said:
I've read that a planet's rotation around it's star is in the same direction has the rotation of the star on itself, is that true?
Generally, yes. But it is not a rule.

_DJ_british_? said:
If so, why? Does it have something to do with the conservation of angular momentum?.
Yes. The star and planets all condensed from the same cloud of dust and gas, and it is this cloud's initial rotation that is preserved.

_DJ_british_? said:
And another question (well, two :P) : why do stars rotate (the outer layer, I mean)(And if it does, the inners?) ?
See above.
_DJ_british_? said:
And do all stars rotate? If not, why some do and some don't (four questions, I guess!)?
Don't know of any that don't. Do you?
 
  • #3
_DJ_british_? said:
I've read that a planet's rotation around it's star is in the same direction has the rotation of the star on itself, is that true?

Kind of true. It's the direction the planets have as they orbit the Sun because they condensed from the same rotating mass as the Sun. Less true for rotation on their axes, as Venus rotates retrograde and Uranus and Pluto are tipped over.

If so, why? Does it have something to do with the conservation of angular momentum?

Yes. It's also hard to reverse direction when you're a planet.

And another question (well, two :P) : why do stars rotate (the outer layer, I mean)(And if it does, the inners?) ? And do all stars rotate? If not, why some do and some don't (four questions, I guess!)?

They all do, some much, much faster than others. It's an active field of research as to how they get fast or slow. The Sun's sluggish rotation is probably due to magnetic braking during its formation. Through interacting with the disk of ionized gas around it, the Sun lost rotational energy like a gigantic "disk brake".
 
  • #4
Just wanted to say thanks for ze info!
 

1. How does the rotation of a planet affect its climate?

The rotation of a planet affects its climate by influencing the distribution of sunlight and heat across its surface. A faster rotation can lead to more extreme temperature variations between day and night, while a slower rotation can result in more moderate temperatures. Additionally, the tilt of a planet's axis can also impact its climate, as it determines the angle at which sunlight hits different parts of the planet.

2. Why do some planets rotate in the opposite direction of others?

The direction of a planet's rotation is determined by the direction of its initial spin during its formation. Planets are believed to have formed from the same spinning disk of gas and dust, but various factors such as collisions and gravitational interactions with other objects can cause a planet to rotate in the opposite direction.

3. What is the difference between a planet's sidereal day and solar day?

A planet's sidereal day is the length of time it takes for the planet to complete one full rotation on its axis relative to the stars. A solar day, on the other hand, is the length of time it takes for the planet to rotate once and return to the same position relative to the sun. The difference between the two is caused by the planet's orbit around the sun and can vary depending on the planet's axial tilt and orbital eccentricity.

4. Can a planet's rotation be affected by external forces?

Yes, a planet's rotation can be affected by external forces such as the gravitational pull of other planets or objects. This can cause small changes in a planet's rotational speed or axis tilt over time. For example, Earth's rotation is gradually slowing down due to tidal forces from the moon.

5. How does the rotation of a planet affect its magnetic field?

The rotation of a planet is one of the key factors that determines the strength and structure of its magnetic field. A fast rotation can generate a stronger magnetic field, while a slow rotation can result in a weaker field. The tilt of a planet's axis can also impact the shape and orientation of its magnetic field, as seen in the case of Uranus where its axis is tilted at a 98 degree angle compared to its orbit around the sun.

Similar threads

  • Astronomy and Astrophysics
Replies
2
Views
2K
  • Astronomy and Astrophysics
Replies
2
Views
2K
  • Astronomy and Astrophysics
Replies
1
Views
1K
  • Astronomy and Astrophysics
Replies
19
Views
1K
  • Astronomy and Astrophysics
Replies
6
Views
1K
  • Astronomy and Astrophysics
Replies
11
Views
528
  • Astronomy and Astrophysics
Replies
6
Views
2K
  • Astronomy and Astrophysics
Replies
6
Views
2K
  • Astronomy and Astrophysics
2
Replies
53
Views
5K
Back
Top