Stars in the disks of spiral galaxies have orbits that:
A) are randomly oriented
B) constantly are getting larger
C) mostly aligned in the same plane
D) spiral shaped
E) unaffected by dark matter

Question

Quizplus · Accepted Answer

The stars in disks of spiral galaxies mostly have orbits aligned in the same plane, which is the plane of the disk. This is because the disk formed from the collapse of a rotating cloud of gas and dust, and conservation of angular momentum results in the rotation being mostly in the same direction.

Stars in the Disks of Spiral Galaxies Have Orbits That