On January 13, Astronomers around the world believed that a newly discovered asteroid, 30m in diameter, had a 1 in 4 chance of hitting the Earth within the following 36 hours, somewhere in the northern hemisphere. An object that size would not be a “planet killer” but it would explode in the atmosphere, causing considerable local damage.
Researchers were within minutes of making “the call” to inform President George Bush about the discovery. At the time, the President was preparing for his address the following day at NASA where he shifted its course to manned flight to the moon and Mars. If the call had been made, it would have been a very different speech.
Fortunately, minutes later, an amateur astronomer took a picture of a piece of sky that should have had the rock in it, but didn’t, confirming that the Earth was in no danger. The crisis was over. Within the following days, more observations were made, correcting the size to a massive 500m. Its trajectory took it past the Earth at a distance of 12 million km, well beyond cause for any concern.
The procedures for raising the alarm in such circumstances are now being revised. Many astronomers recognise that a false alarm could have brought ridicule on their profession. They are calling for more planning and less panic if it should happen for real next time.