Science: Update

THE STARDUST mission to bring back samples of cometary dust to Earth is due to blast off tomorrow from the Kennedy Spaceflight Center in Florida. Scientists hope the material collected from Comet Wild-2's tail will tell them more about the elements that existed at the birth of the Solar System nearly five billion years ago. Other scientists, notably Chandra Wickramasinghe of Cardiff University, hope the mission might also bring back evidence of extraterrestial life. He, along with Sir Fred Hoyle, one of the greatest British cosmologists, proposed nearly 20 years ago that microbes from outer space may have "seeded" the Earth about 4 billion years ago to provide the spark for evolution. They were ridiculed then, but now scientists are treating their ideas more seriously, having observed organic molecules in cometary material.

Meanwhile, Professor Wickramasinghe is collaborating with scientists from the Indian Space Research Organisaton to fly a series of balloons into the stratosphere later this year to suck up samples of air that could contain evidence of cometary microbes.

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A STUDY of last year's World Cup has identified the part of the pitch where football matches are won and lost. Scientists have found that it is the "D" zone on the edge of the penalty area. "It's the critical area of the pitch for exploitation of any creative action, and the springboard for true penetration of the defensive line," Tom Reilly of the Research Institute for Sport and Exercise Sciences at Liverpool University, told New Scientist. The study analysed 24 matches and found that successful teams made much greater use of the zone just outside their opponent's penalty area. Successful teams made on average 25 passes from the zone, compared with just 15 passes by losing sides.

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A THINNING ozone layer could have greater impact on agriculture than anticipated from conventional views on the mutation rates of plants caused by ultraviolet radiation. As plants rely on sunshine they are exposed to high levels of UV light but they have an internal sunscreen to limit the damage it might cause to DNA. Virginia Walbot of Stanford University in California reports in Nature that exposure of maize plants to UV light not only damages DNA but activites dormant parts of the genetic material which increase the rate of mutation. She warns that a thinning ozone layer, and corresponding increase in UV could unleash a sustained increase in mutation rate of important crops.