Chapter 11: Exploring Space
Lesson 1- The Solar System (p. D56)
* The Sun and the bodies that revolve around it make up the solar system. The solar system is a small part of a much larger system call the Milky Way galaxy.
__4.6__ billion years old.
(Pluto used to be considered the 9th planet.)
Q. What causes the “tail” of a comet to form?