Galileo’s telescopic discoveries, and especially his observation of sunspots, caused great debate in an age when the heavens were thought to be perfect and unchanging. Christoph Scheiner, a Jesuit mathematician, argued that sunspots were planets or moons crossing in front of the Sun. Galileo, on the other hand, countered that the spots were on or near the surface of the Sun itself, and he supported his position with a series of meticulous observations and mathematical demonstrations that eventually convinced even his rival.

On Sunspots collects the correspondence that constituted the public debate, including the first English translation of Scheiner’s two tracts as well as Galileo’s three letters, which have previously appeared only in abridged form. In addition, Albert Van Helden and Eileen Reeves have supplemented the correspondence with lengthy introductions, extensive notes, and a bibliography. The result will become the standard work on the subject, essential for students and historians of astronomy, the telescope, and early modern Catholicism.

The glowing cloud in Orion's sword, the Orion Nebula is a thing of beauty in the night sky; it is also the closest center of massive star formation--a stellar nursery that reproduces the conditions in which our own Sun formed some 4.5 billion years ago. The study of the Orion Nebula, focused upon by ever more powerful telescopes from Galileo's time to our own, clarifies how stars are formed, and how we have come to understand the process. C. Robert O'Dell has spent a lifetime studying Orion, and in this book he explains what the Nebula is, how it shines, its role in giving birth to stars, and the insights it affords into how common (or rare) planet formation might be.

An account of astronomy's extended engagement with one remarkable celestial object, this book also tells the story of astronomy over the last four centuries. To help readers appreciate the Nebula and its secrets, O'Dell unfolds his tale chronologically, as astrophysical knowledge developed, and our knowledge of the Nebula and the night sky improved.

Because he served as chief scientist for the Hubble Space Telescope, O'Dell conveys a sense of continuity with his professional ancestors as he describes the construction of the world's most powerful observatory. The result is a rare insider's view of this observatory--and, from that unique perspective, an intimate observer's understanding of one of the sky's most instructive and magnificent objects.

A BBC Sky at Night Best Astronomy and Space Book of the Year

“[A] luminous guide to the cosmos…Jo Dunkley swoops from Earth to the observable limits, then explores stellar life cycles, dark matter, cosmic evolution and the soup-to-nuts history of the Universe.”
—Nature

“A grand tour of space and time, from our nearest planetary neighbors to the edge of the observable Universe…If you feel like refreshing your background knowledge…this little gem certainly won’t disappoint.”
—Govert Schilling, BBC Sky at Night

Most of us have heard of black holes and supernovas, galaxies and the Big Bang. But few understand more than the bare facts about the universe we call home. What is really out there? How did it all begin? Where are we going?

Jo Dunkley begins in Earth’s neighborhood, explaining the nature of the Solar System, the stars in our night sky, and the Milky Way. She traces the evolution of the universe from the Big Bang fourteen billion years ago, past the birth of the Sun and our planets, to today and beyond. She then explains cutting-edge debates about such perplexing phenomena as the accelerating expansion of the universe and the possibility that our universe is only one of many. Our Universe conveys with authority and grace the thrill of scientific discovery and a contagious enthusiasm for the endless wonders of space-time.