Data collected by the MESSENGER spacecraft as it flew past Mercury last January has revealed the origin of the planet’s magnetic field, discovered evidence of early volcanic activity and provided a first look at the planet’s surface composition.

New data about the edge of the solar system offer surprises about how the sun interacts with our galaxy.

The first chemical analysis of dirt by the Mars Phoenix Lander supports the notion that liquid water flowed on the Red Planet at some point.

The Large Hadron Collider could generate black holes, but they would be too tiny and short-lived to do any harm and would be no more malevolent than the cosmic rays constantly bombarding Earth, two new reports find.

Astronomers hope that new tools will enable them to capture the first image of one of the 300 known planets orbiting distant stars.

NANTES, France — The first space-based observatories to find and study Earthlike planets won’t be able to image these bodies but will determine their composition by recording their spectra. Now a new study suggests that the telescopes may recognize a twin of Earth much quicker — in fact, in a twinkling. As seen from space, Earth appears to vary its brightness, or twinkle, as different clouds in its atmosphere rotate in and out of view. The clouds are the main source of light reflected from Earth, notes Enric Pallé of the Institute of Astrophysics of the Canary Islands in L...

A theorist says new extrasolar findings prove that the standard model of planet formation is correct.

Astronomers have discovered the first known system of three superEarths beyond the solar system.

A new analysis suggests that the universe exists within a bigger space.

Astronomers have unveiled a 180-foot-long poster showing the sharpest most detailed infrared view ever recorded of stars and dust in the inner Milky Way. To complete the portrait, researchers stitched together more than 800,000 infrared images taken by NASA’s Spitzer Space Telescope, covering a swath of sky 120 degrees across and one degree above and below the plane of our dusty, disk-shaped galaxy. The Spitzer mosaic is expected to be the gold standard for studying the inner region of the galaxy for years to come, notes Barbara Whitney of the Space Science Institute in Madiso...

New studies revise the structure of the Milky Way, exchanging the old map of a four-armed spiral galaxy for a two-arm version. The makeover also includes the discovery of a smaller, short, gaseous arm that is a long-sought counterpart to a similar arm near the galaxy’s center.

Astronomers have discovered the smallest planet known that is beyond the solar system and orbits an ordinary parent body.

The good news is a tentative sighting of ice by the Mars Phoenix Lander. The bad news is the discovery of a glitch in the system that will analyze soil samples.