SDO AIA Image: Solar Activity in ultra-violet range

A full-disk extreme ultraviolet image of the Sun taken by the Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) instrument, showing the temperatures of gases on the solar surface and in the solar atmosphere. 

Red gases are cooler (around 60,000 degrees Celsius), blue and green are warmer (more than 1 million degrees). 

A solar flare is seen at upper left. Spacecraft like the Solar Dynamics Observatory allow us to 'see' wavelengths of light which would be invisible to human eyes. 

In the ultraviolet the Sun's familiar face appears dark, but now we can see that it's surrounded by wispy streamers of gas and blotched with bright regions of intense solar activity, each the size of the Earth.


Picture: SCIENCE PHOTO LIBRARY / NASA / BARCROFT MEDIA