The Big Bear Solar Observatory (BBSO), operated by the New Jersey Institute of Technology (NJIT), is a premier solar research facility in the United States. Located on the north shore of Big Bear Lake in California's San Bernardino Mountains, about 120 kilometers east of Los Angeles, BBSO benefits from the lake's high altitude and cooling influence, creating ideal conditions for observing the Sun. The lake stabilizes air temperatures, reducing ground-layer turbulence and enhancing image quality, while the observatory's location above 2,000 meters provides clearer skies and minimizes atmospheric interference.

BBSO houses the 1.6-meter Goode Solar Telescope (GST), named in honor of Dr. Philip R. Goode, a former director and leading figure in solar physics. The GST is the largest clear-aperture solar telescope in the world, with an off-axis design that eliminates optical obstructions in its light path. This allows for exceptionally detailed observations of solar phenomena, with the telescope able to resolve features as small as 50 kilometers on the Sun's surface. Equipped with advanced adaptive optics (AO), the GST has seen successive generations of AO technology, culminating in a multi-conjugate AO (MCAO) system that corrects atmospheric distortions across a wider field of view. This system uses three deformable mirrors to enhance imaging stability and clarity, essential for studying dynamic solar processes.

The GST directs light through various spectro-polarimeters, including the Visible (VIS) and Near-Infrared Imaging Spectrograph (NIRIS), allowing researchers to analyze the Sun’s magnetic fields and surface dynamics in multiple wavelengths. Additionally, BBSO’s instrumentation includes a cryogenic spectrograph (CYRA) for capturing data at longer wavelengths, expanding the scope of solar observations. Beyond the GST, BBSO operates full-disk patrol telescopes, such as the Full Disk H-alpha Patrol Telescope, which captures continuous images of the entire solar disk in H-alpha light, crucial for monitoring solar activity like flares and prominences.

Originally established with smaller telescopes in the 20-inch class, BBSO transformed with the construction of the GST, which saw "first light" in 2009 and began operations with AO-corrected imaging by 2010. The MCAO system’s successful integration in 2016 extended the observatory's capabilities, making it a vital resource for wide-field solar studies at high temporal resolution.

BBSO also supports collaborative projects in solar research. The observatory is a station for the Global Oscillation Network Group (GONG), a helioseismology initiative run by the National Solar Observatory. Located at the base of the observatory’s 200-meter causeway, the GONG station has been operational since 1995, adding a global perspective to BBSO’s focus on solar oscillations and magnetic fields.

Through its cutting-edge technology and strategic location, BBSO enables groundbreaking research in solar physics, contributing valuable insights into solar activity, magnetic fields, and their effects on space weather. The observatory remains an essential institution for understanding the Sun’s impact on Earth and advancing the field of solar science.