The National Solar Observatory (NSO) advances knowledge of the Sun as the dominant external influence on Earth and as the local archetype of a typical star.

NSO supports facilities that provide forefront observational opportunities for the solar research community, and leads construction of the Daniel K. Inouye Solar Telescope (DKIST) on Maui in Hawaii, to be completed in 2021. DKIST, a collaboration of 22 institutions, will be the largest and most advanced solar telescope in the world, with unprecedented abilities to view details of the Sun. Using adaptive optics technology and a 4-meter telescope, DKIST will explore physical processes that link the Sun to the Earth, and will set the stage to develop enhanced predictive capabilities of explosive solar events that drive geomagnetic storms. DKIST will also further our understanding of other stars by allowing scientists to study fundamental physical processes that occur on their surfaces.

NSO also operates the Synoptic Optical Long-term Investigations of the Sun (SOLIS) and the Global Oscillation Network Group (GONG). SOLIS observes the Sun over decades to understand the solar activity cycle, solar irradiance changes, and energy releases in the solar atmosphere. GONG is a six-station network of extremely sensitive solar imagers located around Earth, including a site on Cerro Tololo in Chile. GONG provides continuous imaging of the Sun and its solar magnetic field, and has been identified as a crucial asset for space weather operational forecasting. AURA operates NSO for the National Science Foundation under a cooperative agreement.