Carl Sagan opened an immense door to stars and planets beyond. His "billions and billions of stars" sentence will linger for some time. Even now, some 40 years after he opened space for many people, we still remember him.
"The universe is less now that he has left it" is what someone expressed in comments. And to whomever wrote this, this is what I feel as well. What he saw and knew is something we will appreciate for decades to come.
Sagan's devotion to teaching provided opportunities for students to learn about this new revelation we experienced, and that our children have learned. Ultimately, our progeny can look through a telescope and view the spots of light in a dark sky.
Sagan would smile and look through Hubble. Ah, there it is! Did you see that?