Galaxies

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

In a clip from the NOVA miniseries "The Fabric of the Cosmos," Brian Greene and his fellow physicists ponder the implications of multiple universes

For the first time, astronomers discover pockets of pristine gas formed in the universe's first few minutes

A sub-satellite of the Saturnian moon would explain two of the most puzzling features of Iapetus. John Matson reports

Most physicists are betting against the idea that neutrinos can pierce the cosmic speed limit, but that has not stopped some researchers from exploring the implications

Dark matter is not just a puzzle. It is a solution

Encounters with the Sagittarius Dwarf Galaxy could have had huge effects on the structure of the Milky Way

A new study may help scientists determine when stars were born

In Brief

Proof of parallel universes radically different from our own may still lie beyond the domain of science

Flagship missions at risk as astrophysics funding shrinks.

A supernova that went off in 1987 produced large quantities of dust, which may explain why galaxies in the early universe were so dusty