Issues

Astronomers hove just prioritized the ways in which they try to discover more about the universe.

The 1990s should see an 8‐m infrared telescope built atop Mauna Kea, a 2.5‐m telescope in a 747 jumbo jet that will fly above 99% of the water vapor in Earth's atmosphere and a 1‐m cryogenic telescope inserted into a 100 000‐km orbit.

The decode will see major improvements in existing radiotelescopes, such as the Very Large Array, and the construction of new instruments for astronomy at millimeter and submillimeter wavelengths.

Since Galileo's time, atmospheric turbulence has limited the resolution of astronomical observations to around 0.5 sec. Now optical and infrared astronomers are on the verge of improving the limiting resolution of their observations by factors of tens or hundreds—even thousands.

A symbiosis is evolving: Astrophysicol observations are elucidating the nature of the elementary particles, while particle theory and experimental techniques address the dark as well as the showy components of the cosmos, and how it all began.

A revitalized program with a balance of large, moderate and small missions, frequent access to space and improved scientific management will lead to major advances in our understanding of the universe.

In topics ranging from the Big Bang to vulcanism on the moons of Jupiter, theoretical advances in the 1980s radically altered the understanding of the universe. In the coming decade, with better data and more realistic models, more answers—and new questions—will be found.