the submillimeter wavelength band. Important new initiatives are under way with the forthcoming construction of the Smithsonian Institution 's submillimeter array and the University of Arizona-Germany Submillimeter Telescope. The Smithsonian array will make subarcsecond images with high spectral resolution for the first time in this important wavelength band. The NSF is supporting construction of a 1.7-m telescope to investigate the feasibility of conducting submillimeter observations from the South Pole.
NASA's Infrared Telescope Facility (IRTF) and the Kuiper Airborne Observatory (KAO) continue to provide important new results in planetary astro-physics, including the direct detection of water vapor in Halley's Comet, the imaging of volcanoes on Io, and the detection of numerous molecules, including water, phosphine, and germane, in the atmosphere of Jupiter.
Radar results play a critical role in planetary astronomy. The radar sensitivity of the Arecibo telescope will be increased by a factor of 10 or more in a joint undertaking by NASA and the NSF. The enhanced telescope will make high-spatial-resolution images of many asteroids and comets and probe the sub-surface properties of many of the natural satellites such as Phobos, Deimos, Io, and Titan. The committee commends NASA and the NSF for collaborations on the Arecibo telescope.
The sun can be studied at a level of detail that is impossible to achieve for any other star, establishing the foundation of our understanding of all stars. The physical regions inside the sun, especially in the convective zone and below, can be probed by observing the oscillation (or “ringing”) of the sun's surface. The technique is similar to studying the interior of the earth by observing seismological waves on the earth's surface. The Global Oscillations Network Group (GONG) project is an international collaboration, supported in this country by the NSF, to set up a chain of telescopes around the world to monitor the sun's oscillations continuously. With GONG data, it will be possible to constrain the interior temperature and density structure of the sun, and to infer its differential rotation as a function of radius, latitude, and depth. The space-borne complement of GONG is a NASA-funded helioseismology instrument on the European Space Agency's (ESA's) Solar-Heliospheric Observatory (SOHO) mission.
The committee regards the completion of the GONG network, with adequate support for its continued operation and data analysis, as being of fundamental importance.