IT TOOK 52 minutes for signals traveling at the speed of light from Galileo's probe of the planet Jupiter to reach NASA's Jet Propulsion Laboratory in California this week. But processing the signals took longer than expected, and the unexpected 10-minute delay before scientists knew they had the data in hand produced what was surely the most agonizing wait in a long and often frustrating attempt to peer into the huge and mysterious planet at the outer reaches of the solar system.
Despite obstacles, Galileo had accomplished the core of its $1.3 billion mission -- dropping the probe into the stormy, gaseous atmosphere of Jupiter and putting itself in orbit around the planet, where it will stay for almost two years. With that task, mankind also scored another triumph in the age-old quest to explore the world -- and worlds -- around us.
Galileo, launched from a space shuttle six years ago, was delayed three years by the Challenger explosion. Once in flight, the space craft's main antenna, 16 feet wide, failed to deploy properly, putting at risk much of the data the mission hoped to collect. But ever-resourceful scientists were able to reprogram the craft to use a smaller, slower antenna for transmissions, thus rescuing most of the information.
In Thursday's dramatic climax, Galileo acted as a mother ship for the probe, receiving its signals and relaying them back to Earth. The probe was expected to self-destruct in Jupiter's turbulent atmosphere after about 75 minutes. The exact length of its flight will take time to determine, while the data it beamed back will provide years of research for scientists. Because Jupiter still retains characteristics of the cloud of dust and gas out of which grew the planets in our solar system, it holds important clues about the origin of Earth.
As long as human beings have gazed at the stars, they have wondered: What are they like? Where did they come from? Where did we come from?
As another century, and another millennium draws to a close, we have more answers than ever. The challenge now is to continue not just the quest for knowledge, but the twin quest to learn to use it wisely.