christic@cdp.UUCP (08/29/89)
The following is from the Christic Institute in Washington, D.C. In October the next NASA shuttle will launch the Galileo mission to Jupiter. Galileo will be powered by 50 pounds of plutonium. Florida citizens already have protested that the mission's radioactive power supply, if dispersed in an accident over the skies of their state, could represent a serious threat to human life and health. A new development, however, indicates that Galileo could also carry the threat of biological contamination of Jupiter. Despite the severe conditions that exist on Jupiter, Planetary Society President Carl Sagan and other space scientists have speculated that life could exist on the giant planet. A paper published in 1982 by Sagan with a group of other scientists argued that future exploration may find ecological niches in the Jovian atmosphere in which life could have evolved. Sagan's paper concluded that "it seems judicious not to exclude prematurely the possibility of biological contamination of Jupiter by terrestrial microorganisms." The United States and the Soviet Union are parties to a 1967 treaty requiring appropriate measures to prevent the harmful contamination of outer space. In the past, NASA used high temperatures to sterilize spacecraft, but has discontinued this practice. A number of experts believe that despite the harsh environment of outer space, a large colony of earth microorganisms will survive the journey to Jupiter in the interior of the spacecraft. When Galileo reaches Jupiter, the spacecraft will launch a smaller probe into the Jovian atmosphere. The probe's unsterilized parachute will probably carry billions of live microbes. Although conditions on Jupiter are very different from earth, the planet's atmosphere includes clouds of liquid water at temperatures at which earth microbes could survive and grow. Even if the microbes could not survive on their own, the Sagan paper suggests they could find a supportive environment inside native organisms on the planet. The probe will also carry small heating units powered by plutonium. The radioactive material will be released when the probe is crushed by the intense pressures of the Jovian atmosphere. Our first direct contact with Jupiter therefore will pollute the planet with toxic plutonium and probably with alien biological life. The effects of this biological contamination are, of course, impossible to predict. If life already exists on Jupiter, it could be wiped out by the new microorganisms. On the other hand, its evolutionary path might be permanently altered by the introduction of alien life. The danger of contamination raises profound moral and ethical questions for our space program. The Galileo probe could have the same effect on Jovian life as the European settlers who wiped out entire native American communities with the smallpox virus. The Christic Institute supports the exploration of the outer planets, but urges NASA to postpone the Galileo mission until the spacecraft is sterilized and its plutonium generators are replaced by a safer alternative energy source. To learn more about how you can help postpone the Galileo launch, please call or write: The Christic Institute, Public Education Department, 1324 North Capitol Street, N.W., Washington, D.C. 20002. Our phone number is (202) 797-8106.