On the Cover:Mars Observer didn't leave us much, just this "postcard" taken 5.8 million kilometers from Mars on July 26, just 27 days before it lost contact with Earth. From this distance, the planet displays the face familiar to telescopic observers on Earth. The dark feature in the center is Syrtis Major, a region of volcanic plains and sand dunes. At the top is Nilosyrtis, a region of buttes, mesas and box canyons similar to the southwestern deserts of the United States. Near the bottom is the Hellas basin, a circular impact crater some 2,000 kilometers across. JPL / NASA
4 What Happened to Mars Observer?Louis Friedman explains what we know so far.
5 Triumph and Failure: The Way of Planetary Exploration: Louis Friedman gives a brief rundown of planetary missions still in progress or planned.
6 Return to the Wonder World: Mars Observer in Perspective: Carl Sagangives the historical perspective of this failed Mars mission.
8 The Space Station: In the Beginning: Hans Markdescribes the initiation of the Space Station Program.
3 Members' Dialogue Mars Observer, Mercury, and Shoemaker-Levy 9.
16 World Watch An historic agreement between the U.S. and Russia.
18 Readers' Service Tales of the Earth.
19 News & Reviews Biospherians re-emerge.
20 Q&A Impact threats to Earth, the ozone layer, and the solar wind.