How did all the outer planets form?

Answer 1

The other planets were formed many years ago when the atmosphere didn't contain gravity so rocks and dust floated about in space and eventually over time collided with each other then somehow gravity was made and forced the rocks aand dust to stay together

Answer 2

The outer planets, known as gas giants, formed from the gas and dust left over from the formation of the Sun. As the gas and dust in the protoplanetary disk surrounding the young Sun cooled and condensed, gravity caused clumps to form. These clumps eventually grew larger and larger, eventually becoming the gas giants we see today.

Answer 3

ways no one knows