The Planetary Report • March/April 1991

Galileo Encounters Earth

On the Cover: How might our own planet appear to an alien spacecraft sweeping by? This mosaic of images taken by <i>Galileo</i> gives us some idea. Here the snow and ice of Antarctica, surrounded by oceans of liquid water, tell much about the unique nature of this watery planet in our solar system. But could an alien detect signs of life? Not in these images, where features smaller than 5 kilometers (3 miles) are not visible. But a spacecraft like <i>Galileo</i> carries many types of instruments, and some of these did detect evidence of life.


4 The Future of the U.S. Space Program: Norman Augustine reports on the findings of the National Space Council's Advisory Committee on the Future of the U.S. Space Program.

8 From Siberia to Mars: Chris McKay, E. Imre Friedmann, and Michael Meyer search for Mars-like environments in the northernmost edges of Siberia.

12 Galileo Encounters Earth and Venus: Charlene Anderson presents some of Galileo's first findings.

16 Tracking Spacecraft: The Deep Space Network in Spain: Bettyann Kevles explains the potential threat of our flyby neighbors.

20 Prospecting the Future: The Planetary Society Asteroid Program: Charlene Anderson and Louis Friedman introduce a new Society effort to look for near-Earth asteroids.


3 Members' Dialogue The K-T extinction.

7 World Watch The effect of NASA's budget battles on planned missions.

18 News & Reviews Biospheric science; laboratory of Mars.

19 Society Notes Goodbye to an old friend; NEO update.

20 Q&A How do storms last so long on the gas giants compared to Earth?

The Planetary Report • March/April 1991

View Table of Contents

Help advance space science and exploration! Become a member of The Planetary Society and you'll receive the full PDF and print versions of The Planetary Report.