Rotten luck indeed. But two days later Carolyn noticed a peculiar smudge on a few of the telescopic photographs they and their colleague, astronomy writer David Levy, 45, had taken that night. The smudge turned out to be the most celebrated comet discovery of the century.
The Shoemaker-Levy 9, as it's now called, is actually a chain of 21 fragments—the spawn of one giant, icy comet that shattered as it was captured by Jupiter's gravity in 1992. Hurtling through space at 37 miles a second, it resembles a siring of pearls when viewed through the world's largest telescopes. But when the comet hits Jupiter, the resulting explosion will release 10,000 times the energy of Earth's entire stash of nuclear weapons at the peak of the Cold War. It will blow fiery Texas-size holes into the Jovian atmosphere, create a mushroom cloud of debris 1,500 miles high and emit titanic shock waves during a six-day barrage that starts July 18. Though it will only slightly rattle Jupiter, a planet 300 times the size of Earth, it will be the most massive celestial collision ever witnessed in this solar system.
"The only other event in history of comparable force," Astronomy magazine asserts, "is the asteroid or comet that may have struck Earth 65 million years ago, which some scientists speculate wiped out the dinosaurs."
The only thing not surprising about the comet is that the Shoemakers found it. Eugene, 66, who recently retired as the head of the astro-geology department at the U.S. Geological Survey, is a 1992 National Medal of Science winner. Carolyn, 65 and self-trained in astronomy, holds the world record in comet discoveries, with 32. Though at least three other groups had already sighted the aberration near Jupiter, the Shoemakers and Levy were the first to report and identify it. Carolyn's skill at scanning telescopic pictures for the tiny irregular light patterns that signify comets was key in making the identification.
Comprising ice, debris and frozen gases that glow from reflected light, comets typically orbit the sun in a set path (Halley's can be seen on an average of every 77 years). The Shoemaker-Levy 9, however, has been orbiting Jupiter in an irregular ellipse that has brought it ever closer to our solar system's largest planet. Next week its flight will end. "Virtually every telescope in the world will be pointed toward Jupiter in July," said Lucy McFadden, a University of Maryland astronomer.
Born to a teacher and his wife in Los Angeles, Eugene graduated from the California Institute of Technology in 1947 with a major in geology. In 1960 he earned a Ph.D. in geology at Princeton before moving to Flagstaff, Ariz., with his family. In 1951 he married Carolyn, who was born in Chico, Calif., the daughter of a chicken farmer and a teacher. She was the sister of his college roommate. A graduate of Chico State University, Carolyn worked briefly as a seventh-grade teacher before deciding to stay at home to raise their three children: Christine, now 41, Patrick, 38, and Linda, 34. But in 1982, after the kids had moved out, she began helping Eugene with his work. These days, she says cheerily of her nocturnal hours, "we work from dark to dawn."
Next week, the Shoemakers will be among the prominent astronomers heading to Hubble Space Telescope headquarters in Washington to view the hit parade. They're hoping for a spectacular show, even though most of the action will occur on the far side of Jupiter. (Some PBS affiliates will carry pictures from the orbiting Hubble; amateur astronomers will need at least a 10-inch telescope to catch a glimpse.)
Have the couple got complacent? Hardly. Since the discovery of Shoemaker-Levy 9, they've already found three more comets. "I think it's addictive," says Carolyn. "It's still just as exciting every time."
AMY ROFFMANN NEW in Flagstaff
- Amy Roffmann.
ASTRONOMERS CAROLYN AND EUGENE Shoemaker were about to pack it in. "We were having rotten luck," recalls Eugene of the foul weather obscuring the night skies over Palomar Observatory near San Diego during the couple's monthly visit in March 1993. "The clouds kept forming, and it was threatening to snow."