Newly recorded gamma rays from a microquasar may reveal how the black holes or neutron stars powering them can accelerate particles to enormous energies.

Plume of lunar material contained roughly 25 gallons of vapor and ice.

The amount of lithium in the atmosphere of sunlike stars is a powerful indicator of whether such stars have planets, a new study reveals.

Combining infrared and X-ray images from three orbiting observatories, NASA has unveiled a never-before-seen composite portrait of the Milky Way’s bustling center.

The signature of positrons has been found for the first time in gamma rays associated with storms on Earth. (p. 9)

Gamma-ray emissions are providing a guide to finding the compact, rapidly rotating remnants of massive stars known as pulsars.

By detecting gamma rays, a new generation of telescopes bolsters theory that supernovas are origin of some cosmic rays (p. 8)

A new study eliminates some theories of quantum gravity by finding that spacetime isn’t as lumpy as some models had proposed. (p. 14)

The Ares 1 set to replace the space shuttle is too expensive and won’t be ready soon enough, the Augustine Committee concludes.

A mother lode of 32 newly discovered planets brings the number of known extrasolar planets to more than 400 and suggests that lightweight planets are common around sunlike stars. (p. 14)

Data from another craft suggest iron and mercury, not frozen water, were kicked up when a spent rocket plunged into a lunar crater

New observations reveal a dense ribbon structure that current models don't explain. (p. 15)

A proposed ocean on Jupiter’s moon Europa may receive about 100 times more oxygen than previously estimated. (p. 8)