Astronomers have for the first time found evidence of large amounts of frozen water in the subsurface of Mars. (p. 149)

If all goes according to plan, astronauts aboard the space shuttle Columbia will embark on the fourth and most technically challenging mission to replace damaged parts and install new detectors on the Hubble Space Telescope. (p. 132)

After more than 6 years spent touring Jupiter and its four largest moons, the Galileo spacecraft’s mission is beginning to wind down. (p. 125)

Collisions with photons left over from the birth of the universe appear to have generated the longest X ray-emitting jet ever found in a distant galaxy. (p. 101)

Both professional and amateur sky watchers are pointing their telescopes at Jupiter as two titanic storms in the giant planet's upper atmosphere meet each other. (p. 85)

The explosion of nearby supernova may have caused the widespread extinction of marine life on Earth 2 million years ago. (p. 69)

We live in a pale-green universe, according to astronomers who analyzed the colors of some 200,000 galaxies as part of the largest galaxy survey completed to date. (p. 62)

The first image of a planet orbiting a star other than the sun may be only a year away. (p. 62)

A sizable minority of gamma-ray bursts may originate relatively nearby, in galaxies within 325 million light-years of our own. (p. 37)