Icy nucleus of Halley’s comet was drifting in dark silence far beyond the planet Neptune. Its glory extinguished by deep cold, the comet was feeling gravitational tugs from the distant sun, tugs that would pull it back, ever accelerating, into the inner solar system. Four decades later, in January 1985, the comet was passing Jupiter, hurtling toward the asteroid belt at 18 kilometers a second.
At Hawaii’s Mauna Kea Observatory a man who was not even born when the comet made its turnaround was sitting cold and tense at the eyepiece of a 61-centimeter (24-inch) telescope. Breathing oxygen to improve his concentration at Mauna Kea,’s heady summit, Steve O’Meara was pursuing an improbable dream. He wanted to be the first person in 76 years to lay eyes on the comet on its 30th recorded return.
Others already had located the celebrated itinerant electronically. O’Meara, known to fellow amateur astronomers as the “faint-star wizard,” was pressing the limits of human vision. With his naked eyes O’Meara had seen objects 15 times fainter than the distant planet Uranus— invisible to most viewers. Even Uranus was brilliant compared to Halley’s comet, which was bedeviling the professional astronomers working next door that night with electronic detectors on a large 224-centimeter instrument.
“The comet is 300,000 times fainter than the faintest star you could see with the unaided eye,” said University of Hawaii astronomer Dale Cruikshank. “Detecting something so small is like being in New York City and trying to see a penny in St. Louis,” calculated his colleague Bill Hartmann. O’Meara’s night began badly. Using a sky chart, he visually star-hopped to where Halley should be, but he found only stars that were not on his chart. When, after a two-hour search, he sought help, Cruikshank pointed out that he had forgotten to compensate for the longitude difference between Hawaii and his cheap hotels prague.
Next, O’Meara had trouble opening the telescope slit enough to focus on the correct patch of sky. Moreover, subfreezing winds were picking up, threatening to shut down observations. When he finally focused the eyepiece, he noticed three faint stars arrayed in a triangle. Two were not on his chart. Fifteen minutes later he glanced back at the triangle, only to find that it had become a straight line. The star on top had moved. A few minutes later it had dropped farther, forming an inverse image of the original triangle. That was no star, O’Meara realized. The faint-star wizard had found Halley’s comet in flight.
Looking for Halley’s comet this time around wasn’t easy for anyone. Astronomers had warned the public that the comet’s 1986 apparition would be history’s worst. Orbital vagaries kept Halley much farther from earth than on its last visit in 1910. Then its tail practically grazed the planet.”Nature has played a nasty trick on us,” I overheard a small boy complain after viewing the anemic comet from a 200-dollar-aseat jet flight over Australia.