Radio astronomy covers five orders of magnitude in wavelength (300 mm to 30 m) and provides unique as well as complementary windows on the origins of the universe, galaxies, stars, and planets. Radio astronomers sample milliarcsecond scales and millisecond periods. Radio astronomers alone can view the early universe directly through the cosmic microwave background (CMB) and probe large-scale structure independent of redshift using the Sunyaev-Zel’dovich (SZ) effect. Radio waves offer the only clear view of the earliest stages of star and planet formation, both locally and in distant galaxies, by directly probing the dust, magnetic fields, gas dynamics, and rich molecular complexity in the highly obscured environments where galaxies, stars, and planets form.
Not surprisingly, astronomy in the radio and submillimeter wavelength range is driven by technology advances. The last decade has seen the success of the Cosmic Background Explorer (CORE); the completion of the Very Long Baseline Array (VLBA); the launch of the Japanese Very Long Baseline Interferometry (VLBI) Space Observatory Program (VSOP) mission, which pioneered the technique of very-long-baseline interferometry from space; the upgrade of the Arecibo telescope; and the development of millimeter-wave interferometry and submillimeter capabilities. The Green Bank Telescope (GBT), a unique and powerfully flexible instrument exploiting new technology for radio-wave active optics, was dedicated in August 2000. The Atacama Large Millimeter Array (ALMA), the first-ranked major project of the Astronomy and Astrophysics Survey Committee’s Panel on Radio Astronomy a decade ago (it was known then as the Millimeter Array), is currently approaching its construction phase.1 The ALMA project is far more exciting and capable than originally envisaged and will provide the means to explore the dusty sites of planet and star formation and the hearts of the earliest galaxies. The Panel on Radio and Submillimeter-Wave Astronomy reaffirms the high priority given to ALMA by the 1991 Astronomy and Astrophysics Survey Committee and emphasizes that its construction schedule should be maintained.
The panel recommends as its highest priority for major new funding