A nebula collapses down into a disk known called:
A compact disk
An irregular cloud
An protostellar disk
An circular disk
What forms in the very center of the accretion disk?
What two objects do scientists study to learn about the formation of the solar system?
Stars & Star systems
Comets & Asteroids
Comets & Meteoroids
Asteroids & Distant Stars
What happens during nuclear fusion in the sun?
oxygen nuclei combine to form helium
Helium nuclei combine to form oxygen
helium nuclei combine to form hydrogen
hydrogen nuclei combine to form helium