The Same Plane: Orbits & Galaxies in Our Solar System

Click For Summary
SUMMARY

The discussion focuses on the phenomenon of planets and galaxies orbiting in a similar 2D plane, attributed to the conservation of angular momentum during their formation. The process begins with molecular clouds and cosmological overdensities that experience small torques from nearby objects, leading to a slow rotation. As these structures collapse gravitationally, they rotate faster, resulting in a disk-like formation due to the conservation of angular momentum and energy loss through radiative cooling. This explanation highlights the complexities involved in simulating such dynamic systems.

PREREQUISITES
  • Understanding of angular momentum conservation
  • Familiarity with molecular clouds and cosmological overdensities
  • Knowledge of gravitational collapse processes
  • Basic principles of radiative cooling in astrophysics
NEXT STEPS
  • Research the dynamics of molecular clouds in astrophysics
  • Explore simulations of galactic formation using tools like GADGET-2
  • Study the effects of tidal forces on celestial bodies
  • Investigate the role of radiative cooling in star formation
USEFUL FOR

Astronomers, astrophysicists, and students interested in celestial mechanics and the formation of planetary systems and galaxies.

scott_alexsk
Messages
335
Reaction score
0
Why is it that for the most part, all orbiting planets in our solar system orbit together on the same 2D plane. The same can be asked for the disk shape of all of the galaxies. (sp everywhere)
Thanks,
-scott
 
Astronomy news on Phys.org
The short answer is that we don't know. The formation of disks on either galactic or planetary scales are extremely difficult to do because they require your simulation to have a huge dynamic range.

The long and crude answer is that the progenitors to these objects (molecular clouds and cosmological overdensities) can be given small torques by the tidal fields of other nearby objects. This causes the entire progenitor to rotate slowly in some arbitrary direction. Then, as it collapses gravitationally, angular momentum must be conserved and the cloud/overdensity begins to rotate more quickly. This rotation produces a strong asymmetry (along the axis of rotation) in the dynamical system. This system tends to conserve angular momentum about the rotation axis, but lose energy to radiative cooling. The net effect is contraction into a disk rotating roughly about the axis created by the original torque.
 

Similar threads

Undergrad Any Galaxy (Milky-way) based coordinate systems?
  • · Replies 8 ·
Replies
8
Views
2K
Stargazing Planetary orbits -- Why do planets orbit at same “level”?
  • · Replies 5 ·
Replies
5
Views
2K
High School Question about the solar system and gravitational forces
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Galaxies as systems extended from the solar system
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad How to graph Earth's path?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad New Developments In The Search For Planet X
  • · Replies 2 ·
Replies
2
Views
3K
High School Which Way Do Planets in Our Galaxy Spin?
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Planetary Formation: Could Collisions Explain Our Solar System?
  • · Replies 52 ·
2
Replies
52
Views
6K
Undergrad Evidence for existence of a 9th Planet in the solar system
  • · Replies 15 ·
Replies
15
Views
3K
Undergrad Oort Cloud and Kuiper Belt: differences
  • · Replies 3 ·
Replies
3
Views
2K