********************************************************************** *NASA URGED TO SEEK OUT INTELLIGENT LIFE* Space scientists in America have a new dream - to discover another planet like Earth, writes Robin McKie. American scientists are planning to go fishing - for planets. A growing research lobby believes the United States should channel it's space resources towards detecting other solar systems that might support life. The move would shift funding away from expensive manned expeditions, for instance to Mars, and would instead exploit recently established technologies for building oriting observatories, such as the Hubble space telescope. Robert Brown of the Space Telescope Science Institute in Baltimore says: "Such a hunt would strike a chord with the public. The National Aeronautics and Space Administration (NASA) is trying to find a purpose for it's existance. It could do no better than this. It would be popular and make a real contribution to history. Dr Brown, speaking last week at the American Association for the Advancement of Science, is a noted enthusiast for planet-hunting. But he is not alone. Several other speakers stressed that they now believe solar-system spotting has matured sufficiently to begin realistic hunts. Nasa is currently seeking a new rationale. It's orbiting space-station, Freedom, only just survived a series of congressional budget cuts and the agency's traditional approach of planning ever more ambitious manned missions, to culminate in a $50 billion (u31 billion) landing on Mars early next century looks increasingly vulnerable. Critics argue that the two-year mission would only prove what we already know - that Mars is red, dead, and boring. The popular alternative within the space community would be to commit NASA to a search for other worlds, a task which has previously stumped astronomers because stars emit a billion times more light than even the largest planets, like Jupiter. Observer's ability to see smaller, warmer worlds (where life has it's best prospects) against the glare of the stars has therefore proved to be limited. Nevertheless, the first planets have been hooked. At Pennsylvania State University, Dr. Aleksander Wolszczan has detected three - in orbit around a star called PSR 1257+12. The star is a pulsar, an old, extremely dense object, 12 miles in diameter, which revolves at an astonishing 160 times per second. From perturberations in the regular pulses emmitted by this "astronomical lighthouse", Dr. Wolszczan detected two planets slightly bigger han Earth and one much smaller, about the size of Mercury. His discovery suggests planets may be ubiquitous, for if they can survive near pulsars, created when starts first explode as supernovae and then condense in on themselves, they should exist everywhere. The cataclysmic creation of PSR 1257+12 should have destroyed any planets in it's vicinity. So how did they get there? Researchers speculate that PSR 1257+12 may have had a companion star from which the pulsar slowly drew off gas and dust until it's partner was destroyed. From the debris planets evolved. Life there must be slightly odd, however. "You would have to protect yourself against a giant pulsing x-ray machine," Dr. Wolszczan said. "You would have to carry a lead umbrella all the time." Not surprisingly, scientists look to other, far more "normal" stars for signs of planets that might support life. "There are about 1,000 stars like our Sun within 100 light years of Earth, so there should be no shortage of fish in our pond," said David Latham of the Harvard-Smithsonian Centre for astrophysics. "For example, Tau Ceti, near the constellation Pisces, is only 11.7 light years distant and is extraordinarily like our Sun. It must be a very good prospect." And if there are plenty of promising stars, ans evidence that planets are ubiquitous, our extra-terrestial search should have considerable promise. Unfortunatly, other conference speakers provided evidence that undermined this optimism. Research by Andrea Ghez of the university of California, Los Angeles, has found that three-quarters of young stars are born with one or more companion stars. "That is bad news for planets' prospects," she said. "Planets form out of disks of dusk that slowly accrete into larger and larger bodies. A companion star would sweep through these disks, depleting the dust and rocks. There would not be enough left for planets. Solar systems may be the the exception, not the rule, in our galaxy." Scientists are faced, therefore, with contradictory evidence about the ubiquity of other worlds. But now they posses the means to begin to find out who is right. "We have finally built a telescope outside our atmosphere which will detect other planets," Dr. Brown said. "We will soon finish the Copernican Revolution. We have shown planets go around the Sun, but may soon be able to show they go round other stars as well." Dr. Brown said advanced cameras were due to be flown to the space telescope in 2002. These would exploit methods, known as Fourier techniques, which would suppress the glare of o star and reveal it's planets, if any. Once these new worlds had been detected, a new space telescope, on the Moon or in deep space - could be built to study such planets' atmospheres for the presence of chemicals produced by living beings. Such a telecscope would probably exploit the principles of interferometry, in which two seperate instruments combine to produce extremely powerful observations. If it sounds like a dream, consider the words of the NASA director Daniel Goldin: "What if we were to build an interferometer on the moon? And what if it were big enough that we could not only image planets around distant stars, but do spectroscopic analyses of their atmospheres? Results might "change our society in matters we can't even comprehend". Humanity would either learn that life is rare, and therefore precious, or that humans are just an "ever so 'umble" species in an alien-filled universe. "We should get the answer soon," Dr. Brown said. "We have put out hooks. Soon we will be draining the lake.." ********************************************************************** "change our society in matters we can't even comprehend" Hmmm.. sounds as if "they" are preparing to "find" some aliens.. :) :::%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%::: :::%%%ET-=-MAILSYSTEM. "ET" ::: :::%%%%%%%%%%%%%%%%%%%%%%%AMIGA%%%%%%%%%%%%%%%%%%%%%%%:::