Science & history · Looking at the Sun
Solar images are colour-coded
The gold, teal and violet Suns in NASA's pictures are not what the Sun looks like. They are maps of light we cannot see.
One channel, one colour
NASA's Solar Dynamics Observatory records the Sun in many wavelengths and converts its data to colours we can see; each colour corresponds to a different temperature and region. The 304 Å channel shows the chromosphere and transition region at about 50,000 K; 171 Å the quiet corona at about 600,000 K; 193 Å the corona at about 1.3 million K, and hot flare plasma (SDO channel list).
Browse pictures and science data
The quick pictures SDO posts are browse images, one per channel about every 15 minutes. Science work uses calibrated files, and precise pointing is not final for several days. A colour on a browse image is not a temperature reading, and lining two images up exactly takes more than placing them side by side.
Sources
- NASA Scientific Visualization Studio Why Does NASA Observe the Sun in Different Colors? (opens in a new tab) for the Sun appears white because it emits all visible colours; SDO's colours stand for wavelengths, temperatures and regions · checked 2 October 2026
- NASA Solar Dynamics Observatory AIA and HMI channels (opens in a new tab) for each channel's wavelength, region and characteristic temperature (log T) · checked 2 October 2026
- NASA Solar Dynamics Observatory Ways to Access SDO Data (opens in a new tab) for browse JPEGs every 15 minutes vs calibrated FITS; pointing finalised days later · checked 2 October 2026