We are excited that you are taking an astronomy
course and using our book. You
are going to see some amazing things,
from the icy rings of Saturn to monster
black holes. We are proud to be your
guides as you explore.
We have developed this book to help
you expand your knowledge of astronomy,
from recognizing the moon and a
few stars in the evening sky, to a deeper
understanding of the extent, power, and
diversity of the universe. You will meet
worlds where it rains methane, stars so
dense their atoms are crushed, colliding
galaxies that are ripping each other apart,
and a universe that is expanding faster
and faster.