A NASA satellite, launched in 2010 February, to improve understanding of solar activity and its effects on Earth. The Helioseismic and Magnetic Imager (HMI) measures solar oscillations and the magnetic fields on the photosphere to determine how processes inside the Sun are related to surface activity; the Atmospheric Imaging Assembly (AIA) monitors the Sun’s corona at high resolution; and the Extreme Ultraviolet Variability Experiment (EVE) monitors the Sun’s emission at extreme ultraviolet wavelengths.

http://sdo.gsfc.nasa.gov/ Official mission website.