Future Studies Will Extend Census of Middleweight Black Holes
The current census of middleweight black holes is incomplete in many ways. Additional studies will push astrophysicists' understanding of and search for middleweights in new directions
Stephen Hawking, "Equal to Anything!" [Excerpt]
A new biography of Stephen Hawking by long-time acquaintance Kitty Ferguson explores the famous physicist's life and theories in honor of his 70th birthday
Middleweight Black Holes: Clues to the Universe's Evolution
Tipping the scales at less than about a million suns in mass, middleweight black holes may hold clues to how their much larger siblings, and galaxies, first formed
Our Galaxy's "Big Ears": Milky Way's Large Companion Galaxies Stand Out
The Milky Way seems to have too few galactic hangers-on, except when it comes to the big ones. What gives?
Gas Guzzler: Cloud Could Soon Meet Its Demise in Milky Way's Black Hole
The supermassive black hole at our galaxy's center may be about to shred and consume a cloud of gas and dust the size of a planet
Black Holes Dwarf the One in Milky Way
Galaxies NGC 3842 and NGC 4889 host black holes, each of which about 2,500 times the mass of the one at the center of the Milky Way. John Matson reports
Monster Black Holes Are Most Massive Ever Discovered
The discovery, of objects 9.7 billion solar masses large or more, suggests there is still much to learn about how monster black holes grow
Recommended: Relics: Travels in Nature's Time Machine
Books and recommendation from Scientific American
Breaking the Deep-Space Barrier [Interactive]
How a spacecraft propelled by ion drives could deliver humanity deeper into space than ever before. Read more in our special report on deep-space exploration
What Is Life Like in Other Parts of the Multiverse? [Video]
In a clip from the NOVA miniseries "The Fabric of the Cosmos," Brian Greene and his fellow physicists ponder the implications of multiple universes
Fresh Start: Scientists Glimpse Unsullied Traces of the Infant Universe
For the first time, astronomers discover pockets of pristine gas formed in the universe's first few minutes
Did Saturn's Moon Iapetus Once Have Its Own Moon?
A sub-satellite of the Saturnian moon would explain two of the most puzzling features of Iapetus. John Matson reports