Mauna Loa Solar Observatory (MLSO) is a solar observatory located on the slopes of Mauna Loa on the island of Hawaii in the US state of Hawaii. It is operated by the High Altitude Observatory (HAO), a laboratory within the National Center for Atmospheric Research (NCAR).The MLSO sits on property managed by the Mauna Loa Observatory (MLO), which is part of the National Oceanographic and Atmospheric Administration (NOAA)). MLSO was built in 1965.
The MLSO is tasked with monitoring the solar atmosphere and recording data on plasmic and energetic emissions from the chromosphere and corona. Studies of coronal mass ejections (CMEs) are also conducted at MLSO. A number of non-solar astronomical observatories are located at the site. The MLSO instruments record images of the solar disk and limb every 3 minutes for 3–10 hours daily starting at 17:00 UT, weather permitting.
The Advanced Coronal Observing System (ACOS) is a set of instruments for monitoring the chromosphere on a shared mount.
The Coronado Solarmax 60 (CS60) is a small refractor built by Meade Instruments which provides H-alpha disk and limb images.
Chromospheric Helium-I Imaging Photometer (CHIP) observes at a wavelength which is an emission line for non-ionized helium (He I) in order to monitor the chromosphere.
The Coronal Multi-channel Polarimeter (CoMP) monitors the magnetic field in the corona by recording the strength and polarization of light received from corona.
The Precision Solar Photometric Telescope (PSPT) produces highly accurate images of the photosphere at five different wavelengths.