

Throughout history, our nightly view of the universe has fueled our collective imagination. When it comes to the Big Bang, not even the most creative work of imagination can rival what science has revealed about the birth of the universe.

This episode traces our view of the Milky Way, from the mythology of ancient sky watchers to the efforts of scientists to map it from the inside out.

Mercury is one Earth's closest neighbors, but for centuries it eluded astronomer's best efforts to learn its secrets. But that has changed thanks to missions like Mariner and most recently, Messenger.

Cosmic rays can tell us much about the universe. They are not simply another form of light, but carriers of information about powerful and unseen processes at work thousands or even millions of light years away.