WHERE TO FROM HERE?
If just some of the dreams of the science visionaries come true, the next century promises to bit a bold new era of exploration and discovery in astronomy.
With ever more
sophisticated technology and mountains of data pouring in, it is hard to imagine what revelations even the next 25 years will bring. We will never understand everything about the universe because each answer poses new questions, but astronomers are closing in on some notable controversies: the existence of fossilized forms of microbiotic life on Mars; the intriguing conditions on the moons of Jupiter; the ages of the oldest stars; the presence of Earth-like planets around other stars; and the distances to remote galaxies. Still ahead lie the daunting tasks of ascertaining the true size and age of the universe, the physical characteristics of the earliest galaxies, and the composition of the mysterious "dark matter," said to constitute more than 90 percent of the universe's matter.
In some respects, the future is already here. Ground-based astronomy is using new mirror-making technology to create larger, less-expensive telescopes. With computer controlled optics to counteract the effects of Earth's atmosphere, these instruments will be almost like space telescopes on the ground. Radio telescopes linked to form the equivalent of one huge telescope will look into the hearts of galaxies and quasars, and map the universe for unknown sources of radio energy.
Space missions currently underway include NASA's Cassini-Huygens mission, a seven-year, 2 billion mile (3.2 billion km) journey to Saturn. Soon after arrival, it will deploy the European-built
Huygens probe to explore the atmosphere and surface of the giant moon Titan. Then the Cassini orbiter will embark on a four-year tour of Saturn, S sending back data about the planet, its 18 known moons, and its spectacular ring system. Scientists have ambitious plans for Mars, too. Leading off is the Mars Pathfinder, which arrived at the planet on
4 July 1997. Its surface-rover,
Sojourner, studied Martian geology, analyzed soil, and transmitted exciting images of surface features. Hot on its heels is the Mars Global
Surveyor, which will orbit the planet to map surface topography, mineral distribution, and global weather.
In February 1996, NASA launched its Near Earth
Asteroid Rendezvous mission.
The NEAR spacecraft's trajectory first takes a flyby look at asteroid 253 Mathilde, but its ultimate destination is 433 Eros, in 1999. It will orbit and study Eros's surface for a year, giving scientists their first look at an asteroid of a type that has collided with Earth.