Help Shape the Future of Space Exploration

Join The Planetary Society Now  arrow.png

Join our eNewsletter for updates & action alerts

    Please leave this field empty
The Planetary Report
Galileo Encounters Earth On the Cover: How might our own planet appear to an alien spacecraft sweeping by? This mosaic of images taken by Galileo 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 Galileo carries many types of instruments, and some of these did detect evidence of life.

Volume 11, number 2
March/April 1991

Galileo Encounters Earth

Download this issue as a PDF
(Planetary Society members only)


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? 

Facebook Twitter Email RSS AddThis

Essential Advocacy

Our Advocacy Program provides each Society member a voice in the process.

Funding is critical. The more we have, the more effective we can be, translating into more missions, more science, and more exploration.


Space in Images

Pretty pictures and
awe-inspiring science.

See More

Join The Planetary Society

Let’s explore the cosmos together!

Become a Member

Connect With Us

Facebook, Twitter, YouTube and more…
Continue the conversation with our online community!