HAO's Mauna Loa Solar Observatory (MLSO) has been operating since 1965 on the flank of Mauna Loa at 3440 meters, providing scientifically useful images of the Sun to solar researchers and the public.

The COSMO K-Coronagraph (K-Cor) operates at MLSO. It is the first white light coronagraph to view the very low corona (down to 40,000 kilometers) outside of a total solar eclipse. Many explosive solar events form in the very low corona. K-Cor is designed to record the formation and acceleration of Coronal Mass Ejections (CMEs) and associated prominence eruptions.

CMEs, such as the close-up shown here, are the most spectacular form of solar activity. They are violent events that eject part of the Sun's outer atmosphere into interplanetary space and drive the largest geomagnetic storms at Earth.


K-Cor (here, seen inside of MLSO's dome) observes the region of the corona excluded by space-based telescopes, providing crucial information about CMEs. K-Cor observations are provided on the MLSO web page within 15 minutes of acquisition so they can be used for Space Weather forecasting.

Observing the Sun's chromosphere requires viewing in H-alpha light, produced by hydrogen atoms at temperatures between 5 and 10 thousand degrees Kelvin. H-alpha images show solar features such as prominences, filaments, Moreton waves, and optical flares. A Moreton wave can be caused by coronal mass ejections or large flares and travel fast along the surface. An example is shown here, taken through an H-alpha filter at MLSO.


The figure above shows H-alpha images during solar maximum and minimum. During the peak of activity, many more filaments (long dark structures) and plage (bright features) appear due to the complexity of the magnetic field. At solar minimum, the global magnetic field is considerably less complex and fewer features are present.

The featured event movie (glowing green border) shows a chromospheric wave, also known as a Moreton wave or solar tsunami, as seen by MLSO's CHIP instrument (which images the Sun's chromosphere in the Helium line). Waves like these affect the structure of the chromosphere and may contribute to the heating of both the chromosphere and higher lying regions. They have characteristic speeds of around 1000 kilometers per second. This particular wave was initiated by an X6.5 flare.

The Solar Dynamics Observatory (SDO) is the first mission to be launched for NASA's Living With a Star Program, a program designed to understand the causes of solar variability and its impacts on Earth. SDO is designed to help us understand the Sun's influence on Earth and Near-Earth space by studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously.

If the geomagnetic activity level is high, the chance for auroras goes up. We are currently in solar cycle 25, with the next solar maximum predicted to be between 2023 and 2026.

The solar map above shows the current active region numbers and locations assigned by NOAA's Space Weather Prediction Center. The colored circle below the active region indicates the activity level and hazard potential of an active region (see key). If flares occur in the orange shaded area on the right side of the map, they are more likely to be directed towards Earth.

Sunspot numbers for the past solar cycle, with a short-term prediction of future values.

HAO's Mauna Loa Solar Observatory (MLSO) has been operating since 1965 on the flank of Mauna Loa at 3440 meters, providing scientifically useful images of the Sun to solar researchers and the public.

The COSMO K-Coronagraph (K-Cor) operates at MLSO. It is the first white light coronagraph to view the very low corona (down to 40,000 kilometers) outside of a total solar eclipse. Many explosive solar events form in the very low corona. K-Cor is designed to record the formation and acceleration of Coronal Mass Ejections (CMEs) and associated prominence eruptions.

CMEs, such as the close-up shown here, are the most spectacular form of solar activity. They are violent events that eject part of the Sun's outer atmosphere into interplanetary space and drive the largest geomagnetic storms at Earth.


K-Cor (here, seen inside of MLSO's dome) observes the region of the corona excluded by space-based telescopes, providing crucial information about CMEs. K-Cor observations are provided on the MLSO web page within 15 minutes of acquisition so they can be used for Space Weather forecasting.

Observing the Sun's chromosphere requires viewing in H-alpha light, produced by hydrogen atoms at temperatures between 5 and 10 thousand degrees Kelvin. H-alpha images show solar features such as prominences, filaments, Moreton waves, and optical flares. A Moreton wave can be caused by coronal mass ejections or large flares and travel fast along the surface. An example is shown here, taken through an H-alpha filter at MLSO.


The figure above shows H-alpha images during solar maximum and minimum. During the peak of activity, many more filaments (long dark structures) and plage (bright features) appear due to the complexity of the magnetic field. At solar minimum, the global magnetic field is considerably less complex and fewer features are present.

The featured event movie (glowing green border) shows a chromospheric wave, also known as a Moreton wave or solar tsunami, as seen by MLSO's CHIP instrument (which images the Sun's chromosphere in the Helium line). Waves like these affect the structure of the chromosphere and may contribute to the heating of both the chromosphere and higher lying regions. They have characteristic speeds of around 1000 kilometers per second. This particular wave was initiated by an X6.5 flare.

The Solar Dynamics Observatory (SDO) is the first mission to be launched for NASA's Living With a Star Program, a program designed to understand the causes of solar variability and its impacts on Earth. SDO is designed to help us understand the Sun's influence on Earth and Near-Earth space by studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously.

If the geomagnetic activity level is high, the chance for auroras goes up. We are currently in solar cycle 25, with the next solar maximum predicted to be between 2023 and 2026.

The solar map above shows the current active region numbers and locations assigned by NOAA's Space Weather Prediction Center. The colored circle below the active region indicates the activity level and hazard potential of an active region (see key). If flares occur in the orange shaded area on the right side of the map, they are more likely to be directed towards Earth.

Sunspot numbers for the past solar cycle, with a short-term prediction of future values.