based observations are likely to remain highly competitive over the coming decade. The largest challenge to these observations is to detect the B-mode polarization that may be associated with very long wavelength gravitational radiation that was set down during the epoch of inflation.
Exoplanet Initiatives. The discovery and the study of exoplanets are developing at an extraordinarily rapid pace. It will be important to make strategic investments in new ground-based capabilities during the coming decade. One important component will be the aggressive development of ground-based high-precision radial velocity surveys of nearby stars at optical and near-infrared wavelengths (including efforts to determine the effects of stellar activity on these measurements). These surveys will need new spectrometers and significant time allocation on 8- to 10-meter-class telescopes. Another possibility is the development of ground-based high-spatial-resolution techniques in an exoplanet context for direct and indirect detection, and a third, facilities dedicated to surveying exozodiacal dust around nearby stars from the ground.
Next-Generation Adaptive Optics Systems. The adaptive optics technique can correct the distortions that are introduced by turbulence in Earth’s atmosphere in images taken with ground-based telescopes. This technique enables near-infrared images to be obtained with resolution superior to that provided by the Hubble Space Telescope. The next generation of such systems deployed on the existing 8- to 10-meter telescopes will offer major improvements in the quality and wavelength coverage of the images, and in the fraction of the sky accessible to adaptive optics.
Next-Generation Instruments for Solar Telescopes. The Advanced Technology Solar Telescope (ATST) is currently in the MREFC construction queue. The Mid-Scale Innovations Program would be one avenue for providing a second generation of instruments for this facility and maintaining its cutting-edge capabilities.
High Altitude Water Čerenkov Experiment. The High Altitude Water Čerenkov experiment (HAWC), sited in Mexico, is proposed to map the sky at gamma-ray energies above 1 TeV and detect transient sources. With its very large field of view, it will complement the proposed atmospheric Čerenkov facility.