Why is the Oort cloud a sphere rather than a disc?

Question

Since the solar system was created from a disc of material, why is the Oort cloud a sphere? Why didn't the Oort cloud colapse into a disc of material when the nebula did that created the solar system did?

Answer 1

The Oort Cloud is spherical because it is so distant from the inner cloud which collapsed into a disk. Plus the gravitational effect of other Oort Cloud objects, suns that pass by, and other molecular clouds that pass by have randomized the orbits of the objects in the Oort Cloud.

Answer 2

I thought that the current understanding was that the Oort cloud was formed after the formation of the Solar System as a result of debris being thrown out of the inner solar system by the giant planets.

The randomness of that action accounts for the scattering of the cometary material in all directions, creating a sphere of material believed to contain trillions of comets.

Answer 3

Short period comets all come in from the plane of the ecliptic. We have now confirmed the existence of the Kuiper Belt (perhaps better named the transneptunian belt), a belt of hundreds (likely thousands or millions) of icy bodies out beyond Neptune's orbit.

Long period comets, however, are apt to enter the solar system not just on the plane of the ecliptic (the plane the planets orbit in), but from any direction. To account for these comets Jan Oort proposed a spherical cloud of objects out way beyond the orbit of Pluto/Charon. Even beyond the orbits of Varuna, Quoaor, and Sedna (Sedna is bigger than Pluto).

Unlike the Kuiper belt, we really don't have proof the Oort Cloud is there yet, except for the long period comet orbits. Most astronomers are convinced it does exist, and rightly so.

Answer 4

when the nebula condensed and created a hot dense core it caused a build up of hot material, and when the material got to dense it exploded shooting debris in all directions. The hot center was of course our sun. The debris shot all over the place started to once condense again, soon a monopoly occurred, and 8 planets were made. The Oort Cloud was too far away to condense inward towards the newly made planets. So they stayed orbited out beyond the gravitational pull. Basically any material inward of the Oort cloud was drawn in towards the sun, making planets. However im not sure why the asteroid belt did not condense into planets. the asteroid belt is like in the middle of jupiter and saturn. However, occassionally asteroids crash into jupiter. Jupiter is like a vacuum cleaner.

Answer 5

Theories say Oort cloud is actually the remains of the nebula (a cloud, not a disc) that collapsed to create our solar system. This left-over debris remains in highly elliptical orbit off the ecliptic plane.