Researchers unveil state-of-the-art simulation of galaxy formation. (p. 9)

Researchers announce an intriguing new finding about the most energetic charged particles in the universe. (p. 8)

A speedy stellar neighbor may be a refugee from another galaxy. (p. 9)

A familiar star, visible to the naked eye, has shrunk dramatically in just 15 years. (p. 9)

The giant black holes at the cores of massive nearby galaxies may be two to four times heftier than estimated. (p. 5)

Researchers unveil imprints made 20 years before Edison invented phonograph.

Plumes of Enceladus offer hints that moon is now or was in the recent past partially liquid inside.

During five successful space walks, astronauts repaired and rejuvenated the Hubble Space Telescope.

Two new studies document how crystalline dust forms in the hot, inner part of a young star’s planet-making disk and then gets incorporated into the cold, comet-forming region billions of kilometers away.