Findings may aid Earth

Press, 31 August 1989, Page 8

Findings may aid Earth

NZPA-AP Pasadena, California Voyager 2 cruised away from Neptune and towards the stars yesterday, completing a SUSB6S million ($1469 million) trek past 60 worlds, a triumphant exploration that might help humans prevent destruction of their own planet. “If you want to understand Earth, go look at other worlds,” said the Cornell University astronomer Carl Sagan, a member of the team that analysed about 81,000 photographs taken by Voyager 2 and its twin, Voyager 1. "Our passion to explore, our deep need to understand our origins, and the very urgent and practical matter of safeguarding our planet are all enormously enhanced by studying other planets,” he said. Scientists planned a final news conference at the National Aeronautics and Space Administration’s Jet Propulsion Laboratory to summarise Voyager 2’s discoveries. The one tonne spacecraft was 4.44 billion km from Earth and 6.7 million km beyond Neptune, the solar system’s fourth-largest and currently most-distant planet. Voyager also was nearly 7.24 billion km along a curving path that took it from Earth&in 1977, past Jupiter in 1979, Saturn in 1981 and

Uranus in 1986, and now past Neptune in search of the edge of the solar system. Voyager 1 explored Jupiter in 1979 and Saturn in 1980.

The twin Voyagers visited four planets with at least 56 moons, discovering at least 23 of the satellites and examining worlds of wonder, such as Jupiter’s moon 10, with its sulphur-spewing volcanoes. At Neptune, Voyager 2 discovered six moons in addition to Nereid and Triton, which were first detected from Earth. It discovered three thin rings of debris and two broad rings orbiting the planet. It found at least six moonlets hidden in one of the rings. The spacecraft detected in Neptune’s bluish skies an Earth-sized swirling storm called the Great Dark Spot, 1160kmh winds, photochemical smog, invisible ultraviolet auroras and cirrus clouds of natural gas casting shadows on clouds far below.

On icy, pinkish Triton, Voyager revealed bizarre volcanic activity — giant, inactive craters that produce ocean-size floods of flowing ice lava.

“These observations are just as arcane as the discoveriejxOf Captain Cook or even the postlKmous ac-

counts of Magellan,” said the Planetary Society’s vice president, Bruce Murray, former director of the Jet Propulsion Laboratory. “The discoveries challenge our imagination and seem just like science fiction. But they may be very important and very relevant to our grandchildren and their grandchildren.”

The knowledge gathered by the Voyagers might help alert their human masters to the vulnerability of Earth, a tiny garden threatened by nuclear warfare, the greenhouse effect and destruction of the ozone shield.

“If you look who discovered these dangers.. .you find a remarkable preponderance of present and past planetary scientists,” Dr Sagan said. He said Voyager also helped satisfy human wanderlust and sought to answer that most fundamental question — “where we come from, how we fit into the grand cosmological scheme.” Voyager 2 keeps looking back at Neptune until October 2. Then, like Voyager 1, it will spend the next 20 or 30 years collecting information about particles and magnetic fields in space and searching for thetedge of the solar system.