When Planets Form

While all the action of star birth happens at the center of a rotating disk of gas and dust, farther out in the disk atoms, molecules, and dust grains collide and stick together. As these form larger concentrations of mass, they sweep up matter in their vicinity through gravitational attraction. Those objects with the most mass eventually grow into planets.

View the slideshow:
Images of alien worlds and where they are made.
OOOI©2014 Space Science Institute, All Rights Reserved. Alien Earths - www.alienearths.org