The first mammal cloned from an adult cell, whose 1996 birth raised the specter of human cloning, was euthanized February 14 after developing a lung tumor. Dolly got arthritis early in life, which critics cite as evidence of cloning's potential perils. Waggishly named for Dolly Parton because her genesis was a mammary gland cell, the Finn Dorset sheep is now stuffed and on exhibit at the National Museum of Scotland.
Martha Chase, 75
The former lab assistant who, with the switch of a Waring blender, changed the path of genetics died of pneumonia August 8. In 1952, Chase and microbiologist Alfred D. Hershey demonstrated that DNA, not protein, is the carrier of genetic information. The work inspired James Watson and Francis Crick, who discovered DNA's double helix structure 11 months later.
Edward Teller, 95
An inventor of the hydrogen bomb, whose zeal for nuclear-weapons development made him a model for Stanley Kubrick's Dr. Strangelove, died of a stroke September 9.
After a 2.8-billion-mile hike around Jupiter, the spacecraft obliterated itself September 21 by crashing into the planet, as directed by NASA engineers. Launched in 1989, Galileo stayed in orbit an extra six years and amassed a long list of firsts: the first asteroid fly-by; the first sighting of a moon orbiting an asteroid; the first detailed analysis of Jupiter's atmosphere. Galileo's findings also suggested there's a vast ocean under the icy surface of Jupiter's moon Europa -- raising the prospect of extraterrestrial life.
The world's only supersonic passenger service was permanently mothballed in October due to high prices (New York?London round-trip: $9,000-plus), low demand and aging craft increasingly in need of costly maintenance.
THE TOP SCIENCE STORIES OF 2003
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.