Sky & Telescope June 1998 [antikvár]

On March iith Roger Sinnott sauntered into my office grinning from ear to ear. "This is a first," he burbled, " an exclamation point in an lAU Circular!" Roger was referring to a just-issued statement by Brian Marsden that a mile-wide body called 1997 XF would pass some 29,000 miles from Earth on October 26, 2028. But what riveted my attention was the error bar on the distance 10 times the distance itself. This thing might actually hit us!That night the media frenzied. The next morning's Boston Globe quoted Marsden as saying, "The chance of an actual collision is small, but one is not entirely out of the question."Less than a day after the initial announcement Donald Yeomans and Paul Chodas at NASA's Jet Propulsion Laboratory issued their own analysis, opening the minimum distance to 54,000 miles and stating categorically: "Probability of impact: 0 (that's zero folks)." And soon thereafter both Marsden and Yeomans pushed the miss distance out to 600,000 miles after incorporating new observations.The media reported "all clear."Imagine the poor guy on the street getting these contradictory messages. Could he have thought anything but, "Astronomers are jerks for scaring us like that!" And the guy is right. It's one thing for astronomers to announce they've discovered a pulsar and later realize they observed an auto ignition who cares? But to suggest mass destruction one day and retract it the next is unacceptable.All the parties who might have had something to say should have been consulted before a public announcement was made. They should have spoken with one voice. In a telephone interview, Wesley Huntress, NASA's Associate Administrator for Space Science, said: "It's become a story not about asteroids but about the credibility of the scientific community." Apparently the community got the message, for plans are afoot to set up protocols for validating future intruders before an announcement is made.And what about that "zero-impact" forecast? Should it have been believed by the press? Absolutely not! First, other astronomers disagreed with it. And who's to say that 1997 XF,, isn't a tired comet that might yawn and send itself right at us? Or maybe it will get nudged by some interplanetary cohort with the same result.I imagine the public thinks there's a government observatory where all the astronomers do their hocus-pocus in unison. Why shouldn't the guy on the street scratch his head and wonder, "Why don't they get it right?"How much credibility has the astronomical community lost by this public-relations debacle? We'll find out when the next Earth-grazer comes by. Meanwhile, moviemakers should cash in this summer (see page 26).NO UTURN